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L 1.01 - Climate change and its likely effects on food production Farquhar G. (Graham.farquhar@anu.edu.au), Lim W.H., Sun F.B., Wong S.C., Roderick M. Environmental Biology Group, Research School of Biology, Australian National University, GPO Box 475, Canberra City, ACT 2601, Australia. We examine scenarios for future climate change, noting that the Framework Convention on Climate Change includes the direct effects of changes in carbon dioxide concentration itself as part of the definition of climate change. There could be a range of effects on food production, from the direct environmental ones to those on trade and the diversion to biofuel production, and including such biological issues as temperature effects on plant development and meiosis. The possible changes in rainfall and in the incidence of drought, changes in evaporative demand, and CO2 effects on transpiration efficiency are the issues most relevant to this conference. The basic nature of the water vapour feedback in climate change, and hence on the temperature increase to be expected for a doubling of carbon dioxide concentration, is still uncertain as it is sensitive to the changes in humidity in the upper troposphere. Nevertheless, we will examine the predictions of models that all have conventional treatments of this feedback. We examine the outputs of the models used in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Total global changes in rainfall are easier to predict than regional ones. We take Australia as an example to examine in detail, and will discuss China if there is time. We discuss the chaotic nature of climate and the implications for interpreting both observations and modelled predictions. Some models are thought to predict more climatic variability. What do IPCC AR4 models say about variability in rainfall? The other climatic side to water use is evaporative demand. We examine past trends, including the pan evaporation paradox. We examine the role of solar dimming (caused by aerosols) and ‘stilling’, the reduction in windspeed. We speculate about future changes in evaporative demand. Finally we turn to biological issues. We examine the effects of changing carbon dioxide concentration on photosynthesis and transpiration, and in particular on their ratio, transpiration efficiency (TE). We consider how increased [CO2] should improve TE. We speculate on adaptation of Rubisco to changes in the environment ([CO2] [O2] and temperature). We emphasise that many of the projected difficulties associated with adjustment or adaptation to climate change are ones that farmers have dealt with before, and emphasise that research on water-use efficiency and drought tolerance for present-day problems will be valuable for future climates, just as will research on improvement of yield potential.

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L 1.02 - Maintaining food production under environmental challenge: the biologists response Zhang Q.F. (qifazh@hzau.edu.cn) National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.

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L 1.03 - Water resource for agriculture development in China Peng S.Q. (pengsq@agri.gov.cn) National Agro-Technical Extension and Service Centre, MOA. In the past nearly 60 years, China's agriculture has been rapid development. The food supply has been greatly guaranteed. The other agricultural products have greatly improved people's lives. In all of the technologies, such as varieties, cultivation, fertilizers, pest and disease control, the development of irrigated agriculture has played a very important role. China's irrigated land has expanded impressively from 15.9 million hectare in 1950’s to 57.8 million hectares in 2007. It covered 47.4% of the total arable land. The amount of water use for irrigated land has increased 368 in 1978 billion cubic meters, accounting for 66% of the total water resources supply a year. With urbanization and improvement of people's living standards, amount of water use for domestic and industrial has also increased. If the absence of new water sources exploitation, much of water supply will be diverted to domestic and industrial. According to an annual average of 320 billion's irrigation water supply, the matching of land and water resources is about 2670 m3 / ha. The development of agriculture is increasingly constrained by the shortage of water resources. China still accounted for 60% of the land area is the arid and semi-arid areas. In this region, agricultural production relies on natural rainfall exclusively with the lower and unstable yield. Each year, Agricultural production also suffered the threat of severe drought. The direct reduction of grain output reached 20 billion kilograms a year. The area of orchards and vegetables is growing rapidly. It is becoming a new growth point of the irrigation water use. Water-saving and raise efficiency of water use in agriculture is an important guarantee for agricultural development in the future. China needs to maintain agriculture in the existing conditions of water supply, especially the steady growth of grain. In accordance with national strategy, the grain production capacity will reach more than 550 billion kilograms by comprehensive grain production capacity will increase more than 50 billion kg in 2020. This paper attempts to have an analysis on the water use and problem in China's agricultural development in the past nearly 60 years, forecasting demand of water resources for agriculture development in 2020. This paper also will discuss the potential of China's agricultural development and requirement of the technologies.

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L 1.04 - The Engineering of C4 photosynthesis into C3 crops: implications for water use efficiency Sage R. (r.sage@utoronto.ca) Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, On M5S3B2 Canada. The water use efficiency (WUE) of C4 photosynthesis is two to four times greater than that of C3 photosynthesis, resulting in greater biomass yield of C4 plants on restricted supplies of water. The greater WUE of C4 plants arose in later phases of C4 evolution, when the C4-metabolic cycle (the C4 pump) was established. High activity of the C4 pump may further increase WUE in plants from arid environments, as it can compensate for very low stomatal aperture by pumping sufficient CO2 into the bundle sheath tissue to sustain high rates of photosynthesis. Thus, C4 photosynthesis is more flexible than C3 photosynthesis in responding to drought, and hence would be a desirable trait to engineer into C3 crop plants. Engineering C4 photosynthesis into C3 crops has long been considered an overly ambitious if not insurmountable challenge, because dozens if not hundreds of genes would have to be altered in a C3 plant to establish a functioning C4 pathway. The recent realization that C4 photosynthesis independently evolved over 50 times indicates it is not a difficult trait to develop. With this in mind, the International Rice Research Institute has initiated a project to engineer the C4 pathway into rice, the most important C3 crop in warm climates. The project envisions a 20 to 25 year timeline with the initial phase being the discovery of the genes controlling the expression of Kranz anatomy and the C4 pump, and the identification of efficient transformation systems for moving C4 genes into rice. Successful engineering of C4 rice could enhance rice yield per hectare by up to 50%; however, large improvements in rice stocks could also occur because high WUE C4 rice could be grown over a much larger land area than at present, due to less water required for a successful harvest.

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L 2.01 - Water scarcity and the FAO model AQUACROP Steduto P.1 (Pasquale.Steduto@fao.org), Hsiao T.C.2, Fereres E.3, Raes D.4 1 Land and Water Division, FAO, United Nation, Rome, Italy; 2 Department of Land, Air and Water Resources, University of California, Davis, USA; 3 IAS-CSIC and University of Cordoba, Spain; 4 Department of Earth and Environmental Sciences, K.U. Leuven University, Belgium. Demographic growth and economic development are putting unprecedented pressure on renewable, but finite water resources, especially in arid regions. By 2025, 1.8 billion people are expected to be living in countries or regions with “absolute” water scarcity (<500 m3 per year per capita), and two-thirds of the world population will approach “stress” conditions (between 500 and 1000 m3 per year per capita). Rapidly growing urban areas, climate change and bio-energy demands will amplify the already complex relationship between world development and water demand. In brief, a large quota of the world is facing progressive water scarcity conditions. Today’s agriculture uses 70 per cent of all fresh water withdrawals globally, and up to 95 per cent in several developing countries, to meet the present food demand. Therefore, the agricultural sector offers the larger scope for scrutinizing the options to cope with water scarcity. It remains imperative to demand for more efficient and productive water use of farming systems as large amounts of water is consumed by evapotranspiration. To address these aspects, FAO has developed a model, AquaCrop, which simulates attainable yields of the major herbaceous crops in response to water. As compared to other crop models, AquaCrop has a significantly smaller number of parameters and attempts to strike a balance between simplicity, accuracy and robustness. Root zone water content is simulated by keeping track of incoming and outgoing water fluxes at its boundaries, considering the soil as a water storage reservoir with up to 12 layers. Instead of leaf area index, AquaCrop uses canopy ground cover. Canopy expansion, stomatal conductance, canopy senescence and harvest index are the key physiological processes which respond to water stress. Low and high temperature stresses on pollination and biomass production are considered as well. Evapotranspiration is simulated as crop transpiration and soil evaporation and the daily transpiration is used to calculate the daily biomass gain via the normalized biomass water productivity of the crop. The normalization is for atmospheric evaporative demand and carbon dioxide concentration to make the model applicable to diverse locations and seasons, including future climate scenarios. AquaCrop accommodates different water management systems, including rainfed, supplementary, deficit, and full irrigation. Simulations can be carried out both on calendar and thermal time, and future versions, currently under development, will incorporate effects of soil salinity. AquaCrop is mainly aimed at applications at the level of extension services, consulting firms, governmental agencies, NGOs, farmers associations, and farmers. Conceptual and algorithm features of the AquaCrop are illustrated along with some tests and field validation.

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L 2.02 - Managing efficient use of water in extensive dryland wheat farming systems Kirkegaard J. (john.kirkegaard@csiro.au), Hunt J. CSIRO Plant Industry, GPO Box 1600, Canberra ACT, 2601 Australia. Crop scientists generally agree that improvements in water productivity and yield arise from interactions of new crop varieties (G) and their management (M) in particular environments or farming systems (G*E*M). Comparing performance against physiological benchmarks has proven a successful stimulus for improvement, but an understanding of the risk and economic consequences of pursuing higher yield ultimately drives management decisions. Much of the M considered by breeders and physiologists to date has focused on in-crop management (variety, sowing time, plant density, N management) while significant opportunities to capture more water and use it efficiently commence in preceding years and in fallow periods prior to cropping (e.g. rotation, weed control, stubble management). The impact of individual management options on water capture and use may be clear but the relative importance and potential interactions over the season may be less obvious. In some cases management strategies might sensibly substitute for proposed genetic improvements while in others G*M synergies can provide greater benefits. Simulation studies can assist in extrapolating experimental results in this regard, although many important biotic constraints to productivity and water use are not accounted for by current models. We use the dryland wheat production systems to demonstrate how a range of management decisions influence water productivity and yield and tease out the important G*E*M interactions that have driven progress in recent years. We also consider the novel genetic and management options of the future in the context of a changing climate (E) and suggest that research efforts can be better structured to capture G*E*M synergies in a less serendipitous way.

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L 2.03 - SVAT modeling of crop physiological response to drought in potatoes under different types of deficit irrigation Plauborg F.1 (finn.plauborg@agrsci.dk), Mollerup M.2, Abrahamsen P.2, Liu F.L.3, Iversen B.V.1, Ahmadi S. H.1, Andersen M.N. 1, Jensen C.R.3, Hansen S.2 1 Dept. of Agroecology and Environment, Faculty of Agricultural Sciences, University of Aarhus, Denmark; 2 Dept. of Basic Sciences and Environment; 3 Dept. of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen, Denmark. Further understanding of the crop physiologic responses to drought caused by deficit irrigation (DI), regular or partial root drying (PRD), have been obtained in several studies in tomatoes and potatoes under controlled environment. The improved quantitative description of the production of abscisic acid in the root system and as well as its influence on stomatal regulation of gas exhange has been implemented in the Daisy model, a comprehensive work partly financed by the SAFIR project (www.safir4eu.org). Hence, the improved Daisy model now calculates crop production based on gas exchange (CO2 and H2O) from the canopy configured as a big leaf with sun and shade compartments where the gas exchange in its basics is described according to the theory of Farquhar and Ball-Berry, but further modified to include effects of ABA signaling. The Daisy model has as well been further developed to include 2D root development, water and nitrogen uptake to enable studies of the effect of PRD/DI on improving water-use- efficiency. The present paper presents the new processes implemented in Daisy, and a comprehensive test of the model against data obtained under field conditions. Preliminary results show some discrepancies between modeled and measured ABA production, probably due to the fact that the latter was obtained from pot experiments. Further, the modeling work show a reasonable fit to measured 2D soil water content, but further refinement of the model is needed to explain water flow in a potato ridge system, which in fact is a 3D structure.

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L 2.04 - Productive performance and response of Greenchilli (Capsicum annum l.) to drip irriga- tion schedules under water limited conditions Ramachandrappa B.K 1(bkr_agron@yahoo.co.in)，Nanjappa H.V. 2 1 All India Coordinated Research Project For Dryland Agriculture, University of Agricultural Sciences,

G.K.V.K, Bangalore-65, India; 2 University of Agricultural Sciences, Bangalore-65, India. Drip irrigation is often preferred under water limited conditions over the other irrigation methods because of its high water application efficiency on account of reduced surface evaporation and percolation losses. The major limitation of drip irrigation is its initial investment. Therefore, there is a need to reduce the cost of drip installation by altering the planting geometry besides enhancing the productivity and moisture use. Results of the two years field study conducted on sandy loam soils revealed that drip irrigation at 1.0 Epan with normal row system (60 cm×

30 cm) registered significantly higher yield of green chilli(14.08 t·ha-1) which was on par with 0.8 Epan two rows paired system (90-45-90 cm×30 cm:13.45 t·ha-1) and significantly lowest was noticed with 0.6 Epan four rows paired system (45-45-45-120 cm×30cm ) (5.50 t·ha-1). The quality parameters viz, TSS and Ascorbic acid were significantly higher with drip irrigation at 1.0 Epan with normal row system and lowest was observed with 0.6 Epan four rows paired system. Total water used was maximum in 1.0 Epan (691.7 mm) followed by 0.8 Epan irrigation (590.2 mm) and the lowest was recorded in 0.6 Epan irrigation (488.8 mm). There was a saving of water by 14.68 percent and 29.34 percent under 0.8 and 0.6 Epan drip irrigation schedules respectively over 1.0 Epan. Indications of less leaf water potential in 1.0 Epan drip irrigation (-0.58 to – 0.67 MPa) followed by 0.8 Epan (-0.61 to – 0.68 MPa) and more negative leaf water potential in 0.6 Epan (-0.71 to -0.88 MPa) in relation to water applied were observed. Changes in the status of soil moisture and soil water potential in drip irrigation schedules were discussed in this paper in relation to plant response under water limited conditions and productivity. Water use efficiency recorded was maximum in 0.6 Epan normal row systems (24.1 kg ha·mm-1) and the least was recorded in 0.6 Epan four rows paired system (11.3 kg ha-mm-1). The significantly higher root growth characters such as root length (42.6 cm), number of primary roots (28.7), root dry weight (11.05 g·plant-1) and maximum depth of penetration were recorded with 0.6 Epan four rows paired system and the least was observed with 1.0 Epan with normal row system. This indicating root proliferation under stress conditions and marked performance in terms of yield under water limited environments. Significantly higher Benefit: Cost ratio was recorded with 0.8 Epan two rows paired system (2.24:1) and was on par with 1.0 Epan two rows paired system (2.00:1) and 1.0 Epan normal row system (1.85:1). The significantly lowest B: C ratio was noticed with 0.6 Epan four rows paired system. Agronomic techniques can be used to enhance water use efficiency and productivity under drip irrigation in water limited environment.

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L 2.05 - New stage for development of dry land farming on Loess Plateau: opportunity for break- through Shan L. (shanlun@ms.iswc.ac.cn) Northwest A & F University, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Conservancy, China. In dry land agriculture practice, there are two approaches to improve field productivity: (1) Environment control development, i.e., improve plant living environment to fit the needs of crops, this includes technologies which reduce soil and water loss, decrease soil water evaporation, increase and maximum use of soil water storage, collect non cultivate field runoffs and use them as irrigation supplement; (2) Approach of biological water saving, i.e., modify plant to adapt the dry environment, this includes genetic modification of Plant, physiological regulation and application of crop complementary effort. These can he obtained by either improving water use ratio in field or by improving plant water use efficiency itself. These two aspects rely on each other. They can not be isolated but need to be separated, because these are two different technological directions. As a typical semiarid area, the dry land agriculture in China’s Loess plateau has gone through some different stages. The core technologies during these stages include: development level terrace field in hilly area, wide application of fertilizer, crop mulching and rain water harvesting. These technologies are well developed and promoted in Loess Plateau and they are reaching to the top of the potential. Therefore dry land farming in Loess Plateau is now facing to a new stage Yield increasing and high usage of limited water resources can be obtained not only from application of environment control technology, but also can be exploited from biological water saving, i.e. improvement of crop to adapt dry environment. Improvement of crop drought resistance and WUE by modifying crop itself will be a key issue in the near future for breakthrough of dry land farming. The three aspects related to biological improvement of drought resistance and water saving were discussed in this paper, it indicates that selection crop varieties which has wide adaptation to highly variance and Low water environment need to be the number l target for crop breeding work in this region. Crop varieties which combine characters of medium high yield with high drought resistance and high WUE are very much desirable. Based on the author’s research work, the theory of drought resistant differences among crops and the theory of plant compensatory effort are the two fundamental theories for establishment of water saving agricultural structure and for the efficiency development of semi-dry land farming . We has reviewed the plant compensatory effort after certain water stress in this paper, since it is indeed a important theoretical basis for achieving a new breakthrough in developing dryland farming and water saving agriculture.

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L 2.06 - Deficit irrigation in fruit trees and vines Fereres E. (ag1fecae@uco.es) IAS-CSIC and University of Cordoba Apartado 4084, 14080-Cordoba, Spain. Increased demands for more food and a more varied diet, together with greater freshwater withdrawals for other uses is creating an unprecedented challenge for irrigation management. In situations of water scarcity, there has been a shift in irrigation water use towards high value crops of high water productivity, mostly horticultural crops. Even for crops such as fruit trees and vines, severe constrains in water supply are not uncommon. Improved water application methods and precise irrigation scheduling reduce water losses (recoverable) to a minimum, but this may not be enough, as net water savings may be needed to match the limited supply available. Reducing evaporation from soil and/or plant transpiration would then be required. This presentation reviews the current state of deficit irrigation (DI) in fruit trees and vines (FTV) with emphasis on the basic physiological reactions to water deficits, and how this knowledge improves our understanding of the yield responses under field conditions. Various approaches to DI have been developed over the last three decades, with mixed success at the adoption level. One positive response to water deficits in FTV is the shift in assimilate partitioning towards fruit production. However, carry over effects of stress into subsequent years have negative impacts in these perennial crop plants. The application of water deficits at certain developmental stages considered insensitive to yield determination, termed regulated DI (RDI), has been successfully used in several crops. Other DI approaches have also been tested and adopted, including the use of DI by watering alternate sides of the tree or vine (PRD). The objective of DI is to maximise net income with the limited water available, and the often observed positive effect of water deficits on crop quality is an important consideration for promoting DI. The increased risks associated with RDI demand the use of advanced sensors and of precision irrigation and here, technology is well ahead of the science. A number of trade-offs when using DI will be discussed, emphasising the sustainability aspects of this practice. The complexity of the responses of FTV to DI, and a lack of physiological research in these perennial crop plants have been important constraints in the development of successful DI practices. Nevertheless, the potential water savings may be substantial, and this is the main driving force behind the recent efforts in research and development of deficit irrigation.

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L 2.07 - Efficient water-saving agriculture in arid northwest China Du T.S., Kang S.Z.(kangshaozhong@tom.com), Li S., Tong L., Wang S.F. Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083 China. Competition for the limited water resource between agriculture and ecosystem is increasingly becoming a serious problem especially in northwest China. Due to the lack of surface water, groundwater has become a major source of irrigation water in these areas. Groundwater levels are persistently declining, and there are a number of regions with significant groundwater depression. In the oasis fields, effective use of limited water resources for crop production will be a great challenge in the future. A typical example is the lower reach of the Shiyang River Basin (Minqin oasis) between the Tenggeli Desert and Badanjilin Desert in the Gansu Province. It is a typical irrigation-dependant oasis with abundant sunlight but limited rainfall (annual precipitation of 110 mm). As a result of the low rainfall and intense competition for water between the upper and lower reaches, the only surface water resource, i.e., the Hongyashan Reservoir at the end of Shiyang River, became dried up in June 2004. To maintain agricultural production and human consumption in the lower reach, deep groundwater at 80-300 m depth has been extracted. Utilization of these water resources has led to some serious consequences, e.g., gradually falling groundwater table, shrinking of vegetation areas, soil salinization and desertification. As the Shiyang River Basin is one of the main agricultural areas in the Hexi Corridor of Gansu Province and has large areas of cereal crops (e.g., spring wheat, maize) and cash crops (e.g., cotton, grape and melon), the competition for water resources between agricultural irrigation and ecological maintenance has also become a difficult problem. In order to explore the suitable pattern of limited water resources utilization and water-saving agriculture, accelerate the demonstration and exploitation of advanced water-saving technology, China Agricultural University built the Shiyanghe Experimental Station for Water-saving in Agriculture and Ecology. The general objective of our research is to investigate the characteristic of water transforming and consuming at river basin scale, collocate the water resource based on ecology water demand, exploit new theory, technology and control approach of improving irrigation water use efficiency with reduction of “luxury evapotranspiration” based on crop water information and obtain the new water use pattern of agriculture and ecology grounded on water cycle and ecology water demand in arid inland river basin. Furthermore, the experimental station accumulate scientific data for research of agro-system in Northwest, provide support for comprehensive reparation of Shiyang River Basin and offer reference and example for water management in arid areas of the world. It also serves for the local water-saving agriculture production and ecosystem restoration with cooperation of local government.

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L 2.08 - Crop management strategies to improve water use efficiency in wheat under water limited conditions Waraich E.A. (uaf_ewarraich @ yahoo.com), Ahmad R.

Department of Crop Physiology, University of Agriculture, Faisalabad, Pakistan. Wheat production in Pakistan is confronted with many constraints among which shortage of irrigation water and frequent droughts are more common and often very serious. Moreover, inefficient use of water is a notorious phenomenon in irrigation system of Pakistan and a significant portion of water is lost during transfer to farmer’s fields. Realizing the need for increased wheat production especially in the scenario of developing water shortage in the country, two sets of field experiments were conducted each, the research area of the Department of Crop Physiology, University of agriculture, Faisalabad, Pakistan. The objective was to determine whether modifications in recommended crop management practices could significantly improve yield and water use efficiency (WUE) in wheat and identify management practices that might be implemented to maximize WUE in wheat under water-limited conditions. In the first experiment, the effects of irrigation and nitrogen on growth, yield, water use and physiological responses in wheat variety Inqlab-91 were determined. Four irrigation regimes and four levels of N were tested. In second experiment, the conventional, flood irrigated-flat planting was compared with furrow irrigated-raised bed planting for wheat. Four planting techniques and two wheat varieties were tested using the randomized complete block design with four replications. The data for gas exchange, water relations, crop growth and development and yield and yield components were recorded during the course of study. Water stress resulting from decrease in number of irrigations consistently resulted in marked decrease in these parameters. Significantly higher values of above-mentioned physiological and yield attributes were observed in 150 kg N ha-1 treatment at all the irrigation levels. Higher GFR was observed for low levels of irrigation and nitrogen than for the high levels. The GFR increased with time being maximum after 20 days of anthesis. Grain filling duration (GFD) was not affected significantly with nitrogen application. The irrigation treatments, however, had a significant effect on GFD. Crude protein concentrations were higher at low levels of irrigation and decreased with increasing number of irrigations. Nitrogen supply improved crude protein concentrations and significantly higher values were recorded for 150 kg N ha-1 level than all other N levels, in both years. Among planting techniques (Experiment II), flat sowing with 11 cm row-to-row distance proved better for the number of tillers, number of spikelets spike-1, number of grains spike-1, grain and biological yield than all other planting techniques. Two wheat varieties showed differential responses to planting techniques. The new line (97050) performed better by producing higher number of tillers, number of spikelets spike-1, number of grains spike-1 and grain yield. Water use efficiency (WUE) decreased with the increasing number of irrigation but increased with the increasing levels of nitrogen (experiment I). Planting wheat on beds (Experiment II) improved water use efficiency in both the years. On average water use efficiency in bed planting was higher (18% in 2000-03 and 45% in 2003-04). New line 97050 proved better regarding WUE, depicting similar trend in both the years of experimentation.

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L 2.09 - Adaptation of rice to uplands in the temperate monsoon region in Japan Kato Y.1 (akko@fm.a.u-tokyo.ac.jp), Okami M.1, Yamagishi J.1, Abe J.2, Nemoto K.2, Kamoshita A.3, Katsura K.4, Hirayama M.5, Manabe T.5

1 Field Production Science Center (FPSC), The University of Tokyo, Japan; 2 AE-Bio, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan; 3 Asian Natural Environmental Science Center, The University of Tokyo, Japan; 4 Experimental Farm, Graduate School of Agriculture, Kyoto University, Japan; 5 Plant Biotechnology Institute, Ibaraki Agricultural Center, Japan. Coping with drought has been a major issue for upland rice (Oryza sativa L.). Japan has a history of research into upland rice, and the breeding program was run from 1929 to 2005. Research objectives included breeding for enhanced adaptability to water limitations. The targeted strategies were the drought escape by early flowering and the drought avoidance by deep root morphology, as the common type of drought was intermittent, mild to moderate drought. A raised bed system for selecting the deep-rooted genotypes was developed in the greenhouse, which was adopted in the breeding program as well as the evaluation of rooting depth in the field. One of the successes was the release of ‘Yumeno-hatamochi’, a deep-rooted elite variety with yield potential of 6-7 t•ha-1. However, it remained a challenging problem to genetically combine a set of high-yielding traits and drought resistant traits. We have studied the physiological characterization of yield potential and drought avoidance of upland rice at the University of Tokyo, Japan on Andisols since 2001. The major findings are: (1) effectiveness of deep rooting for N uptake capacity, (2) importance of constitutive root traits for deep rooting, (3) relevance of leaf water potential to the abortion of spikelets under drought at pre-flowering stage, and (4) large room for raising yield potential. Quantitative trait loci (QTL) analyses, by using a japonica cross (‘Akihikari’בIRAT109’ back- cross-inbred lines), suggested that the genetic improvement of deep rooting can enhance yield stability of upland rice, without sacrificing yield potential. Some of the QTL for high-yielding traits were common in lowlands and uplands. There is a clear scope for improving the ability of rice to uptake more of the available water in uplands, as much of the soil moisture seems to be not exploited by the plants. This will improve both drought resistance and yield potential of upland rice.

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L 3.01 - Genetic variability of growth maintenance under drought: from phenotyping platforms to the field Tardieu F. (tardieu@supagro.inra.fr), Welcker C. INRA, LEPSE 2 place Viala 34060 Montpellier, France. Expansive growth of leaves or of reproductive organs such as silks are affected by water deficit before any reduction in photosynthesis or root growth. An approach combining quantitative genetic, physiology and ecophysiological modelling has been developed to disentangle the genetic basis of growth response to soil water deficit and evaporative demand. - The analysis of a mapping population in 7 fields in Mexico, Kenya and India suggests that the genetic determinisms of leaf area and of grain yield are in good part common, with an overall correlation between both variables. - A considerable genetic variability was observed for the sensitivities of leaf growth to water deficit and evapo- rative demand, measured in phenotyping platforms. In populations of RILs or in panels of unrelated lines, some lines had their growth stopped at a soil water potential of –0.6 MPa while other continued growing until –1.6 MPa. There is therefore a considerable natural genetic variability which can be exploited for breeding. A limited number of genomic regions were repeatedly associated with the sensitivity to soil water deficit and evaporative demand across mapping populations. - The dynamic nature of responses of leaf growth to changes in soil water status or evaporative demand suggests that hydraulic processes significantly contribute to genetic differences in growth maintenance in maize and rice. In particular, abscisic acid largely contributes to increase the tissue hydraulic conductivity, whole plant hydraulic conductance and growth recovery via an increase in aquaporin content and activity. Turgor and hydraulic conductivity play an important role in changes in leaf growth rate. - Comparative mapping in a tropical maize mapping population shows that the genetic determinism of leaf growth maintenance under water deficit is partly common with that of the maintenance of reproductive development1. This suggests common mechanisms between source and sink strengths, with profound consequences for designing drought tolerant ideotypes. - Common QTLs for leaf growth were observed in phenotyping platforms and in the field. Both modelling and experiment show that QTLs for organ growth translate into differences in yield5, opening route to new approaches of breeding combining MAS and modelling.

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L 3.02 - Management techniques to enhance harvest index Yang J.C.1( jcyang@yzu.edu.cn), Zhang J.H.2 (jzhang@hkbu.edu.hk) 1 Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou,

Jiangsu, China; 2 Department of Biology, Hong Kong Baptist University, Hong Kong, China.

A major challenge in rice (Oryza sativa L.) production is to enhance water use efficiency (WUE) and maintain or even increase grain yield. As the grain yield is the product of harvest index and total above-ground biomass, either increase in transpiration efficiency (the ratio of biomass production over transpiration) or increase in harvest index would improve grain yield and WUE. However, transpiration efficiency has been shown to be fairy constant for a given species in given climate, and higher WUE is often a trade-off lower biomass production. Harvest index has been shown a variable factor in crop production, especially in cases where whole plant senescence of rice is unfavorably delayed due to over-use of nitrogen fertilizers, adoption of lodging-resistant cultivars that stay “green” for too long, and introduction of hybrid rice which is too vigorous. This paper discussed the possibility to increase WUE without compromising grain yield through the manipulation of harvest index in the crop. Our results showed that several practices, postanthesis controlled soil drying, alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially enhance WUE and maintain or even increase grain yield of rice, mainly via improved canopy and enhanced remobilization of pre-stored carbon reserves from vegetative tissues to grains. We conclude that proper field practices hold great promise to increase crop water productivity through enhancement in harvest index.

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L 3.03 - Flower and pod production and abortion in two chickpea cultivars under terminal drought Fang X.W.1,2, Turner N.C.1 (ncturner@clima.uwa.edu.au)

1 Centre for Legumes in Mediterranean Agriculture, M080, The University of Western Australia, Crawley, WA 6009, Australia;

2 MOE Key Laboratory of Arid and Grassland Ecology, School of Life Sciences, Lanzhou University, Lanzhou, Gansu 730000, China.

Terminal drought at flowering is a major constraint to yield of chickpea in many regions of the world. The gas exchange, seed yield and its components, including flower and pod production and abortion, and pollen germination and viability of one small-seeded desi chickpea cultivar, Rupali, and one large-seeded kabuli chickpea cultivar, Almaz, were investigated when terminal drought was imposed during flowering and podding. Termination of watering induced a gradual decrease in predawn leaf water potential (LWP), the rate of photosynthesis and stomatal conductance, reduced flower production and increased flower and pod abortion, About 100 flowers/plant were produced when the chickpeas were well watered (WW). After the water stress (WS) treatment was imposed, only about one-third of the flowers were produced compared to the WW controls. In the WW treatment, 86% and 85% of the flowers produced a pod, but in the WS treatment this was reduced to 0 (all flowers aborted) and 24%, in Rupali and Almaz, respectively. Pod abortion was 42%, 54%, 67% and 72% in WW and WS Rupali, and WW and WS Almaz, respectively. The WS plants had higher seed growth rates, but seed size was similar to or less than that in WW plants. The seed yield of Rupali and Almaz after the WS treatment was imposed was reduced by 100% and 89%, respectively, compared with the control. When the LWP declined to -1.2 MPa in the WS Rupali chickpea, pollen viability and germination in vitro decreased from 79±3% and 82±5% to 51±3% and 53±3%, respectively. The number of pollen tubes in the pistils of the WW plants pollinated with pollen from WW plants (WW+WW) and from WS plants (WW+WS) was 12.9±0.6 and 2.5±0.6, while in the pistils of WS plants pollinated with pollen from WW plants (WS+WW) and WS plants (WS+WS) the number was 3.1±1.1 and 0.6±0.5, respectively. The percentage of pollen tubes that reached the ovary was 37±2% in WW+WW, 20±4% in WW+WS, 4.2±2.2% in WS+WW, and 2.0±2.0% in WS+WS. The results showed that water stress reduced both pollen and ovule function, and increased flower, pod and seed abortion, thereby influencing the seed yield of chickpea exposed to terminal drought.

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L 3.04 - Root signals, regulation of water use, and implications for adaptation and selection Wade L. (lwade@csu.edu.au) Charles Sturt University, EH Graham Centre, Wagga Wagga NSW 2678, Australia. In the alternate flooding and drying conditions encountered by rice in the rainfed lowlands, the abundant roots in shallow soil layers were expected to generate signals when droughted, despite the likelihood of additional water in deeper soil layers. This research examined the presence of root signals, their nature and plant responses, the suitability of the methods, and the implications for adaptation and selection. A split-root technique was used in initial greenhouse studies, whereby roots were divided into two sections: flooded and droughted. The decrease in stomatal conductance due to drying of a portion of the roots, and their apparent recovery upon severing of this root portion, were consistent with a role for root signals. The recovery in leaf water potential after severing of droughted roots in the greenhouse could be attributed to increased hydraulic conductance. Rice lines CT9993 and IR62266 were then grown in the field and in the greenhouse with the split-root root-sever system, with wax layers differing in strength placed at hardpan depth, to investigate their responses to mild and severe water deficit. Roots of CT9993 were better able to penetrate the wax layers. IR62266 exhibited stronger responses than CT9993, with IR62266’s stomatal conductance dropping sharply under water deficit, and recovering at slower rates but less completely, when roots subjected to drying soil were severed. The greater stomatal response in IR62266 was associated with a higher leaf ABA concentration during early water deficit, which in turn was associated with its greater number of roots in drying soil. The field study confirmed the evidence for root signals during progressive soil drying, whereby stomatal conductance decreased before leaf water potential started to decline. The increase in leaf ABA concentration under field drought, and its strong association with soil moisture tension and stomatal conductance, suggested its involvement in mediating stomatal responses during early drought in rice. A second reduction in stomatal conductance was observed under severe water deficit in the field, with stronger hydraulic signals in IR62266 associated with more conservative water use as soil drying intensified. These responses demonstrated genotypic variation in root signals, and implied a role for both chemical and hydraulic signals which had important implications for adaptation and crop performance in contrasting rice ecosystems. To better exploit subsoil water, selection for reduced root signals might be warranted for mild or transient water deficit. Conversely, stronger root signals should meter water use for grain filling during prolonged water deficit.

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L 3.05 - Alternating partial root-zone irrigation: a strategy improves water and nitrogen use efficiencies in row crops Liu F.L.1 (fl@life.ku.dk), Wang Y.S.1, Andersen M.N.2, Jensen C.R.1 1 Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen, Denmark; 2 Department of Agroecology and Environment, Faculty of Agricultural Science, University of Aarhus,

Denmark. Water and nitrogen (N) are essential resources for crop production, and their availability has predominant effect on crop yield and quality. Shortage of irrigation water is an important limiting factor in crop production worldwide, and with the projected climate changes it is becoming more significant in the future. N fertilizer is one of the most energy-consuming chemical products, however the utilization efficiency of N fertilizer applied to the field is still low. Therefore, there is an urgent need to develop strategies to use water and N more efficiently in line with principles of sustainable development. Alternate partial root-zone irrigation (PRI) is a novel water-saving irrigation strategy which involves irrigating only part of the root zone leaving the other part to dry to a predetermined level before the next irrigation. The physiological basis for improved water use efficiency (WUE) under PRI has been intensively researched; the mechanism is that PRI allows the induction of the ABA-based root-to-shoot chemical signalling system to regulate growth and water use and thereby increasing WUE. In addition, the drying and wetting cycles in the soil imposed by the PRI will influence crop root growth and activity as well as soil bio-physicochemical processes, which may affect the soil nutrient availability and root nutrient uptake efficiency. An enhanced crop N uptake under PRI has been reported in several crops. Based on these findings, it is suggested that PRI may be a promising management strategy improve both water and N use efficiencies in row crops.

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L 3.06 - Root growth at low water potentials: complexity and coordination of cellular responses Sharp R.E. (sharpr@missouri.edu) Division of Plant Sciences, University of Missouri, Columbia, Missouri 65211, USA. The root system is critical to plant adaptation to drought conditions. Roots can maintain elongation under water stress levels which completely inhibit shoot growth. Maize primary root growth at low water potentials involves a coordinated interplay of cellular responses involving spatially differential regulation of expansion rates, osmotic adjustment, and cell wall extensibility. In water-stressed roots, elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex. This spatial characterization and the physiological knowledge gained to date provide a powerful foundation for functional genomics studies. Proteomic analysis revealed major and predominantly region-specific changes in cell wall protein composition in the growth zone of water-stressed compared to well-watered roots. Several proteins related to reactive oxygen species (ROS) generation, prominent among them being putative oxalate oxidases (OxO), increased in abundance especially in the apical region. Apoplastic ROS may have cell wall loosening or tightening effects which could be region specific, and may also have other growth regulatory functions. To investigate the role of OxO/apoplastic ROS in root elongation, we are studying transgenic maize lines constitutively expressing a wheat OxO gene. Results show that OxO activity is increased in a region-specific manner with different profiles in well-watered and water- stressed roots, and that these changes are associated with differential effects on growth and growth-related processes. Experiments to determine the processes underlying root growth regulation by OxO/apoplastic ROS are in progress. This information could be used to develop plants that produce appropriate amounts of ROS to enhance root growth under water stress conditions. The OxO transgenic studies are in collaboration with J. Simmonds, Agriculture and Agri-Food Canada, Ottawa, Canada.

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L 3.07 - Genetic and genomic dissection of maize root system development Hochholdinger F. (frank.hochholdinger@zmbp.uni-tuebingen.de) Department of General Genetics, Center for Plant Molecular Biology, University of Tuebin- gen, 72076 Tuebingen, Germany. Root stock architecture in maize (Zea mays L.) is determined by various embryonic and postembryonic root types that are formed at different stages of development. While the embryonically formed primary and seminal roots prevail during seedling development, the adult root stock is dominated by an extensive shoot-borne root system. In recent years, a number of maize mutants with specific defects in different root-types have been identified and some of the affected genes have been cloned. Among those, the RTCS gene which encodes an auxin inducible LOB domain transcription factor, is involved in shoot-borne root initiation, while the RUM1 gene which is required for lateral and seminal root initiation, encodes a member of the AUX/IAA gene family. Moreover, the genes RTH1 and RTH3, which encode a SEC3-like and COBRA-like gene, respectively, are involved in root hair elongation. The cloning and recent characterization of these genes as well as related tissue specific proteome and transcriptome analyses will be discussed.

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L 3.08 - Plastic root system development and its contribution to plant growth under drought stress in chromosome segment substitution lines in rice Kano M., Inukai Y., Yamauchi A. (ayama@agr.nagoya-u.ac.jp) Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan. We have shown that the plastic root system development plays an important role for plant adaptation to water stress conditions in rice. This study aimed to evaluate the functional roles of root plasticity to water and nutrient uptake and biomass production. Chromosome segment substitution lines (CSSLs) derived from Nipponbare and Kasalath crosses were used in this study, which are strong tool for evaluating the functional significance of target traits with minimal confounding effects of other traits. These seeds were provided by the Rice Genome Research Center of the National Institute of Agrobiological Sciences, Japan. Among the lines, we previously identified CSSL45 and CSSL50 as highly homozygous to Nipponbare in plant growth under non-stressed condition, but exhibited greater root system development under drought stress. In this study, the seedlings of CSSL45, CSSL50 and recurrent parent Nipponbare were grown in PVC root boxes (40 cm×25 cm×2 cm) filled with 2.5 kg sandy loam soil for 31 days with three treatments: (1) continuously waterlogging (control), (2) 25% soil moisture contents (SMC (w/w%)), (3) 20% SMC. There was no significant difference between genotypes in control for shoot dry weight, photosynthesis, water use and chlorophyll content (SPAD value), while CSSL45 and CSSL50 showed greater shoot dry weight than Nipponbare due to their abilities to promote root system development, which were associated with enhanced water and nutrient uptake under drought stresses. For CSSL45 and CSSL50, the contribution of plastic root development to shoot dry matter production were calculated as 0.25 mg in shoot dry weight increase with 7 m increased root length under 20% SMC and 0.3 to 0.5 mg in shoot dry weight increase with 5 m increased root length under 25% SMC. These results imply that the increased root length due to plastic root development triggered by mild drought stress contributed to maintenance in biomass production under the condition, which needs more root growth with increasing drought intensities.

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L 3.09 - Improving water use efficiency and water capture in Solanum and Brassica: transgenic and QTL approaches Thompson A.J.1(a.j.thompson@warwick.ac.uk), Awan S.1, Hilton H.1, Farquhar G.3, Ryder C.1, Andrews J.1, Harrison L.1, Smeeton R.2, White C.2, Taylor I.B.2 1 Warwick HRI, University of Warwick, Wellesbourne, Warwick, CV35 9EF, UK; 2 Department of Plant Sciences, University of Nottingham, Leicestershire, LE12 5RD, UK; 3 Environmental Biology Group, Australian National University, Canberra, Australia. Abscisic acid (ABA) is a key modulator of plant responses to water deficit and the maintenance of a favorable plant water status. Overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key rate-limiting enzyme for ABA biosynthesis, causes ABA accumulation. An rbcS::NCED construct led to large increases in ABA content in photosynthetic tissues of tomato, together with greatly improved WUE, but with severely detrimental effects on growth. In Arabidopsis the same construct led to smaller increases in ABA accumulation, and in this case large improvements in WUE were accompanied by an only slightly suppressed biomass under well-watered conditions and an improved biomass under water deficit. Tomato lines in which expression of NCED was driven by a constitutive promoter were selected that had moderate increases in ABA content, although in these lines germination and seedling establishment was slow, they produced the same biomass as wild-type plants in the long-term while transpiring 44% less water. Moderately increased ABA levels caused stomatal closure, which may limit CO2 assimilation in some environments, but it also increased leaf water status, leaf expansion and root hydraulic conductivity. It is clear that to obtain benefits from NCED overexpression the level and pattern of expression needs to be optimized, and the combined pleiotropic effects of elevated ABA need to be considered to assess the impact on crop productivity and WUE. We are currently attempting this optimization process. WUE is a complex quantitative genetic trait that is controlled by many genes and that interacts strongly with environmental factors. Many component traits that can be measured from the cellular scale to the whole crop scale contribute to overall WUE, and the genetic loci that control these traits can be identified. We have mapped quantitative trait loci (QTL) for traits related to WUE at the leaf and whole plant scale in Brassica and Arabidopsis, and for root traits related to water capture in Solanum.

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L 3.10 - Modelling chemical signalling when soil moisture is heterogeneous Dodd I.C. (I.Dodd@lancaster.ac.uk) The Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK. High root length density in the upper soil layers commonly results in very significant drying of those layers and marked soil moisture heterogeneity. Although roots in drying soil produce chemical signals such as abscisic acid (ABA), whether this ABA is actually transported to the shoots depends on the proportions of transpirational flux sourced from different roots. Thus drying the upper soil layers increased xylem ABA concentration when plants were grown in soil columns in the greenhouse but had little effect in the field until soil water in the whole profile was close to depletion. Reconciling these apparently conflicting observations requires detailed measurements of sap and ABA fluxes from different parts of the root system. To investigate the contribution of different parts of the root system to total sap flow and leaf xylem ABA concentration ( [X-ABA]leaf ), individual sunflower shoots were grafted onto the root systems of two plants grown in separate pots and sap flow through each hypocotyl measured below the graft union. During deficit irrigation (DI), both pots received the same irrigation volumes, while during partial rootzone drying (PRD) one pot (“wet”) was watered and other (“dry”) was not. During PRD, excessive soil drying decreased the fraction of sap flow from roots in drying roots. Root xylem ABA concentration increased with soil drying in both irrigation treatments. A simple model that weighted ABA contributions of wet and dry root systems to [X-ABA]leaf according to the sap flow from each, revealed that [X-ABA]leaf during PRD exceeded that of DI with moderate soil drying, but continued soil drying (such that sap flow from roots in drying soil ceased) resulted in the opposite effect, as seen experimentally. Differences in chemical signalling between DI and PRD plants supplied with the same irrigation volumes may provide a physiological explanation for yield differences between these treatments in the field.

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L 3.11 - Comparison of cytokinin and auxin roles in the response to drought and combined drought and heat stress and their potential utilization in elevation of stress tolerance Vankova R. (vankova@ueb.cas.cz), Cervinkova H., Novak O., Tureckova V., Dobra J., Storchova H., Pospisilova J., Motyka V. Institute of Experimental Botany AS CR, Prague and Olomouc, Czech Republic. Plant interactions with often unfavourable environment are, at least partially, mediated by phytohormones. Apart from classical stress hormones, which stimulate defence pathways, also other hormones, cytokinins (CKs) and auxins, are involved in stress responses, modulating plant growth and development. Drought response of tobacco plants includes inhibition of growth and preferential protection of upper leaves, coinciding with enhanced plant polarization. CKs (especially trans-zeatin) and auxin (indolylacetic acid – IAA) are indispensable for cell division. They are abundant in fast growing, young tissues. At the stress conditions, their levels in upper leaves are down- regulated. CKs also positively affect sink strength. Their gradient, formed predominantly by isopentenyladenine- type CKs, is established in stressed plants. It is caused at the initial stress phase by CK elevation in upper leaves and during prolonged stress by stimulation of CK degradation with cytokinin oxidase/dehydrogenase in lower leaves. Simultaneously, IAA accumulates in lower leaves, which exhibit accelerated senescence. Application of short heat stress during the strong drought speeds up CK decrease, as well as further auxin increase in lower leaves. Potential role of auxin might be in prevention of leaf abscission before translocation of nutrients from the drying leaves. After rehydration, increase of xylem sap flow strongly contributes to elevation of CKs in leaves (especially of trans-zeatin), which coincides with growth stimulation. Auxin levels quickly decrease in lower leaves. Drought progression was characterized by the expression of selected genes (coding for dehydrin NtERD10B, regulatory protein CSP41 and all three prolin dehydrogenases), by analysis of ABA pool (including its metabolites, predominantly phaseic acid and ABA glucosylester) and by determination of photosynthetic characteristics. Understanding of the mechanisms of CK and auxin function under stress conditions and subsequent recovery is a necessary prerequisite for establishment of a suitable strategy to improve plant tolerance to drought.

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L 4.01 - Ecophysiology meets metabolic profiling: an integrative approach of Arabidopsis thaliana responses to drought Hummel I.1, Pantin F.1, Sulpice R.2, Piques M.2, Rolland G.1, Dauzat M.1, Granier C.1, Stitt M.2, Gibon Y.2, 3 (yves.gibon@bordeaux.inra.fr), Muller B.1

1 INRA-LEPSE, Montpellier, France; 2 MPI-MPP, Golm, Germany; 3 INRA-BF, Bordeaux, France. Understanding what limits plant growth under water deficit is an important issue because it could help in identifying target processes for the improvement of plant performance under drought. Primary metabolism, which provides energy and building blocks to biomass production, has been intensively studied in plants experiencing drought, but no clear picture has emerged so far. In particular, although it is well established that carbon fluxes are severely altered under drought, it is still unclear whether this would primarily affect plant performance. By using an integrative approach combining ecophysiology and multilevel metabolic phenotyping, we investigated growth and metabolism in Arabidopsis plants subjected to mild and severe water deficits for up to several weeks. The results show that under drought, rosette growth rates were more reduced than photosynthesis, leading to an improved carbon balance. K+ and organic acids were the main contributors to osmotic adjustment, and water shortage led to a global increase in the turnover of carbon rich compounds (starch, soluble sugars, organic acids and amino acids), suggesting that relatively more carbon was available at night. A more favorable carbon status at night was confirmed by a shift in the levels of transcripts encoding sugar responsive genes. In contrast, most enzyme activities under study showed only limited response to water stress. Taken together, these data suggest that in our conditions, carbon status did not limit growth, being adjusted to drought, but without requiring an in-depth reprogramming of central metabolism.

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L 4.02 - Metabolic traits related to drought tolerance Parry M.A.J.1 (martin.parry@bbsrc.ac.uk), Carmo-Silva A.E.1,2, Keys A.J.1, Arrabaça M. C.2, Hirano E.1,3, Hey S.J.1, Zhang Y.H.1, Andralojc P.J.1, Primavesi L.F.1, Halford N.G.1, Davies W. J.3

1 Plant Science Department, Rothamsted Research, Harpenden AL5 2JQ, UK; 2 Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; 3 The Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK. The availability of water is a major determinant of world-wide crop yields and even in the UK wheat yield losses due to drought average 1-2 t·ha-1. The losses are much greater in other countries with higher temperatures and lower rainfall. The predicted changes in climate patterns are projected to increase these losses. Although there is genetic variability for drought tolerance and yield stability, these are complex and multigenic traits with a large environmental component which makes breeding for improved performance under drought difficult. In order to better understand the relationship between genotype, component traits, and environment over time we are adopting a multidisciplinary approach to both understand the drought response and identify candidate genes, QTLs and traits that can be used to improve both yield and yield stability under drought. Candidate genes are being evaluated by TILLING and/or genetic modification. Here we have report on some of the physiological and metabolic effects on carbon assimilation and partitioning in C3 and C4 plants and examine how these traits relate to drought tolerance.

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L 4.03 - Understanding and manipulating ABA biosynthesis and signaling for improving drought resistance Zhu J.K. (jian-kang.zhu@ucr.edu) UC Riverside

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L 4.04 - What genes should we clone for water saving agriculture Jia W.S. (jiaws@cau.edu.cn) China Agric. Univ.

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L 4.05 - From QTLs and MAS to candidate genes for root growth and drought avoidance in one rice mapping population Khowaja F.S.1,2, Norton G.J.1, Price A.H.1 (a. price@abdn.ac.uk) 1 Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK; 2 Current address: Lethbridge Research Centre, Lethbridge, AB T1J 4B1, Canada. The Bala x Azucena mapping population has been extensively used to study root growth and drought avoidance QTLs. Marker assisted selection has been successfully used in breeding and in characterising specific QTLs. More recently, meta-analysis of 13 experiments and 1650 individual QTLs has demonstrated the genetic complexity of these traits. This revealed, for example, the presence of 3 root growth QTLs on chromosome 9 and suggested the strong drought avoidance QTL on chromosome 1 is unlikely to be causally linked to the semi-dwarfing gene sd1 which is just outside the 5 cM-long 95% confidence interval. Efforts to identify candidate genes without fine mapping using meta-analysis, transcriptomics and bioinformatics have produced relatively small (80-500) gene list. However, the high degree of sequence polymorphism between the parents (>50% polymorphism in amino acid sequence per gene), which has proved so useful for the mapping of QTLs, limits the identification of candidate genes. None-the-less some candidate genes stand out such as auxin transporters for root-growth QTLs and aquaporins for drought avoidance. Physiological studies on root responses to auxin and root hydraulic conductance supporting the candidature of these genes have been conducted. Further investigation of these candidates is continuing with an association population in collaboration with Cornell University where functionally significant allelic variation is being characterised across 371 rice cultivars. Allelic variation is being combined with phenotype data from IRRI in preliminary efforts to provide evidence of allelic variation associated with field performance. We are currently aiming to verify these in a more balanced study in controlled environments.

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L 4.06 - Arabidopsis EDT1/HDG11 confers drought tolerance with improved root system and increased biomass in both dicots and monocots Xiang C.B. (xiangcb@ustc.edu.cn) China Sci. & Tec. Univ

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L 4.07 - Photosynthesis and carbon metabolism under drought – early warnings and ultimate constraints Chaves M.M.1,2 ( mchaves@isa.utl.pt) , Pinheiro C.1

1 Instituto de Tecnologia Química e Biológica, UNL, Oeiras, Portugal; 2 Instituto Superior de Agronomia, Technical University of Lisbon, Lisbon, Portugal. Photosynthesis is one of the key processes to be affected by water deficits, via decreased CO2 diffusion to the chloroplast and/or metabolic down-regulations (1). The relative impact of those limitations will vary with the intensity of the stress and the occurrence (or not) of superimposed stresses and the species we are dealing with. Total plant carbon uptake is further reduced due to the concomitant or even earlier inhibition of growth. Slower growth was suggested as an adaptation for plant survival under stress, because it allows plants to divert assimilates into stress protective molecules and/or to maintain root growth, improving water acquisition (2). It is acknowledged that leaf carbohydrate status, altered in quantity and quality by water deficits, acts as metabolic signal. Drought generally leads to increased or to constant concentration of soluble sugars in leaves, in spite of lowered carbon assimilation, because growth and export are also inhibited. Under very severe dehydration soluble sugars may decrease. The signalling role of sugars under this context is not totally clear. Some relevant questions include how early acts this signalling, which are the initial metabolic alterations and how are they triggered? Apparently, sugar signalling occurs in very early stages of stress development and is closely related with ABA signalling cascade. Sugars traveling in the xylem of droughted plants are likely to exert an influence on stomatal sensitivity to ABA. On the other hand, molecular analysis indicates that ABA enhances IVR2 vacuolar invertase activity and expression. This may explain the rapid accumulation of glucose and fructose in leaves of droughted plants at the expenses of sucrose, with positive impact on osmotic adjustment. Furthermore, it is acknowledged that a depletion of sugars in the leaves may trigger an increase in photosynthetic activity, presumably due to a de-repression of sugar control on transcription, whereas an accumulation of sugars may have the opposite effect. We will revise the constraints posed to carbon uptake and metabolism in plants subjected to water deficits and their regulatory systems, from the early signaling to the ultimate effects on crop performance.

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L 4.08 - Evaluation of diverse wheat genotypes for drought tolerance using intrinsic mesophyll efficiency and cell membrane stability Munjal R. (munjalrenu@hau.ernet.in) Wheat & Barley Section, Department of Plant Breeding, CCSHAU, Hisar- Haryana, India. India has firmed up its position as the second largest producer of wheat, in the world, only next to China harvesting 78.4 million tones during last crop season from an area of about 27.7 million hectare with a productivity of 2.83 t/ha. The area under wheat crop in India has been hovering around 26-28 million ha. Nonetheless, challenges to wheat production are still considerable, especially in the developing world, not only because of increased demand but also because of the increased scarcity of water resources ever more unpredictable climates. Cultivars with a higher tolerance of drought are required to obtain higher and more stable seed. To achieve this, it is necessary to identify genotypes with good drought tolerance trait as well as developing efficient methods to evaluate levels of drought tolerance traits in genetic resource. The present paper presents the result of an evaluation of drought and heat tolerance screening nursery through physiological parameters An important strategy in the development of drought tolerance in plants is the maintenance of cell membrane integrity during drought stress. Also genetic progress in increasing yield potential is closely associated with increased photosynthetic activity. Intrinsic mesophyll efficiency (Intercellular CO2 concentration/Stomatal conductance) is often considered as a good estimate of photosynthesis. Since no single method is completely successful in discriminating tolerant and sensitive genotypes, the combination of different methods to evaluate diverse germplasm produce better results. Therefore, 56 genotypes evaluated was analysed for cell membrane integrity and intrinsic mesophyll efficiency. Up regulation of the photosynthetic system appears to play a role in drought tolerance of wheat, with tolerant genotypes maintaining relatively higher photosynthetic function. Data observed revealed that there was correlation between intrinsic mesophyll efficiency and cell membrane stability in tolerant genotypes. So it is assumed that intrinsic mesophyll efficiency and cell membrane stability can be used as physiological parameters to screen wheat genotypes for drought tolerance.

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L 4.09 - Heterosis in maize is the result on differences in water status Araus J.L.1,2 (j.araus@cgiar.org), Cabrera-Bosquet L.1,2, Sánchez C.2

1 Unitat de Fisiologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; 2 International Maize and Wheat Improvement Center (CIMMYT), El Batán, Mexico. While heterosis confers stress tolerance in maize the physiological mechanisms underlying remains elusive. A set of 16 inbreeds of tropical maize (Zea mays L.) from La Posta Population and the derived single crosses using a common tester were grown in the field. Three different water regimes were assayed: fully irrigation and two levels of water stress imposed by stop irrigation before anthesis, with an averaged ratio between total water input (rainfall plus irrigation) and reference evapotranspiration of 1.5, 1.0 and 0.5, respectively. Total plant biomass was measured about two weeks after flowering and further grain yield and its agronomical components were assessed at maturity. Plant water status was evaluated by instantaneous and time-integrated measurements. The first consisted in periodical measurements of leaf stomatal conductance and leaf temperature from just prior water treatments were imposed, until middle grain filling. Integrated traits included total mineral (ash) accumulated in the whole leaves of plants harvested during grain filling as well as the enrichment in stable isotope 18O (Δ18O) in the dry matter of the same leaves as well as in mature kernels. Within each growing conditions hybrids showed a better water status, differences being already evident under the fully watered trials. Therefore, for a given water regime, lines exhibit poorer water status than hybrids. Taken the 6 trials together the water status within each trail related almost linearly with the total biomass accumulated during grain filling. The traits best fitting biomass were ash content and Δ18O of leaves and grains (R2 = 0.82, 0.91 and 0.92, respectively). However when the water status traits were correlated with grain yield (R2 = 0.92, 0.90 and 0.76) as well as with total number of kernels per plant (R2 = 0.86, 0.87 and 0.75), the relationship moved to non linear with a threshold where any improvement in water regime increase strongly grain yield and kernel number. Results suggest that differences in biomass as well as in grain yield between lines and hybrids are basically the consequence of differences in water regime.

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L 4.10 - Cytokinin-dependent photorespiration and the protection of photosynthesis during water deficit. Rivero R.M., Walia H., Blumwald E. (eblumwald@ucdavis.edu) Dept. of Plant Sciences, University of California, Davis, CA 95616, USA. Drought accelerates leaf senescence, leading to a decrease in canopy size, loss in photosynthesis and reduced yields. On the basis of the assumption that senescence is a type of cell death program that could be inappropriately activated during drought, we hypothesized that it may be possible to enhance drought tolerance by delaying drought-induced leaf senescence through the stress-induced synthesis of cytokinins. We generated transgenic plants expressing an isopentenyltransferase (IPT) gene driven by pSARK, a stress- and maturation-induced pro- moter. Remarkably, the suppression of drought-induced leaf senescence resulted in outstanding drought tolerance where the transgenic plants expressing pSARK-IPT displayed vigorous growth following a long drought period that killed the control plants. We investigated the effects of IPT expression and cytokinin production on several aspects of photosynthesis in transgenic plants grown under optimal or restricted (30% of the optimal) watering regimes. There were no significant differences in stomatal conductance between leaves from wild-type and SARK-IPT transgenic plants grown under optimal or restricted watering. On the other hand, there was a significant reduction in the maximum rate of electron transport as well as the use of triose phosphates only in the wild-type plants during growth under restricted watering, indicating a biochemical control of photosynthesis during the growth under water deficit. The transgenic plants displayed an increase in catalase inside peroxisomes, a physical association between chloroplasts, peroxisomes and mitochondria and an increase in the CO2-compensation point, indicating the cytokinin-mediated occurrence of photorespiration in the transgenic plants. The contribution of photorespiration to the tolerance of the transgenic plants to water deficit was also supported by the increase in transcripts coding for enzymes involved in the conversion of glycolate to RuBP. Moreover, the increase in photorespiration-related transcripts was further enhanced in the transgenic plants grown under restricted watering conditions, indicating a cytokinin-induced increase in photorespiration and the contribution of photorespiration to protecting photosynthetic processes and playing a beneficial role during water stress. Array-based analysis indicated major expression level difference between the tolerant and wild-type plants for genes involved in photosynthesis processes localized to the chloroplasts. Some of the key genes of PSII, PSI and, ATPase complexes were strongly repressed in the wild-type stressed plants but were unaffected or marginally repressed in stressed PSARK::IPT plants. The production of drought-tolerant crops able to grow under restricted water regimes without diminution of yield would minimize drought-related losses and ensure food production in water-limited lands.

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L 4.11 - Identification and functional analysis of unique proteins associated with drought tolerance in C3 and C4 perennial grass species Xu C.P.1, Zhao Y.2, Du H.M.2, Wang Z.L.2, Huang B.R.1 (huang@aesop.rutgers.edu) 1 Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ 08901, USA; 2 Department of Plant Science, Shanghai Jiao Tong University, Shanghai, China. Drought stress has major adverse impact on perennial grass growth, especially C3 grass species. C4 grass species is generally known for its superior drought tolerance to C3 grass species. However, the molecular mechanisms underlying the differential stress tolerance in C3 and C4 species are not understood. In addition, research for perennial grasses generally lags behind that of the major Poaceae crops, and perennial grass species as a group have received little attention, despite their importance in turf and forage management, as well as bioengery production. The analysis of differential proteomic responses to drought stress in C3 and C4 perennial grass species may provide insights into metabolic and molecular factors regulating drought tolerance in perennial grass species for improving grass growth and production in dry land areas. Studies were conducted to identify proteins differentially-expressed in C3 Kentucky bluegrass (Poa pratensis L.) and C4 bermudagrass (Cynodon spp.) using genotypes differing in drought tolerance for each grass species and to examine biological functions of differentially-expressed proteins involved in drought tolerance in both grass species. Physiological analysis revealed significant genetic variation in leaf desiccation tolerance within and between the two species, as evaluated using relative water content and photochemical efficiency, and cell membrane stability. Proteins were extracted and separated using differential two-dimensional gel electrophoresis. The sequences of proteins differrentially expressed under well-watered and drought stress in Kentucky bluegrass and bermudagrass were determined using mass spectrometry, and protein functions were analyzed. Many proteins involved in amino acid metabolism or energy metabolism were down- regulated under drought stress, but most proteins were maintained at a higher level in the drought-tolerant bermudagrass and Kentucky bluegrass genotype. Our studies demonstrated that C3 and C4 grass species shared some common metabolic pathways, such as maintaining amino acid and energy metabolism, for adaptation to drought stress. Most interestingly, C3 and C4 grass species expressed unique proteins responsive to drought stress that were specific for each species. Kentucky bluegrass tolerance to drought stress was associated with the up-regulation of proteins involved in electron transport (ferredoxin-NADP oxidoreductase and oxygen- evolving complex) and carbon assimilation, such as Rubisco activase, controlling photosynthesis and the accumulation of heat shock proteins, whereas bermudagrass drought tolerance was related to the accumulation of dehydrins and proteins involved in antioxidant defense, such as ascorbate peroxidase and dehydroascorbate reductase. The differential expression of unique proteins may account for the genetic variation in drought tolerance in C3 and C4 perennial grass species.

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L 4.12 - Aquaporins: molecular gears for adjusting root and leaf hydraulics to a changing environment Maurel C. (maurel@supagro.inra.fr), Postaire O., Boursiac Y., Tournaire-Roux C., Sutka M., Li G.W., Santoni V., Luu D.T., Verdoucq L. Biochemistry and Plant Molecular Physiology, CNRS/INRA UMR5004, 2 place Viala, F-34060 Mont- pellier, France. Aquaporins are water channel proteins present in the plasma and intracellular membranes of plant cells. Genetic approaches in Arabidopsis based on the analysis of knock-out mutants and of naturally occurring genetic variations of root water transport have provided complementary insights into the role of PIP plasma membrane aquaporins during root water uptake. A combination of pharmacological and reverse genetic approaches also showed that PIPs contribute to water transport in the inner tissues of leaves and can account for light-dependent changes in their hydraulic conductivity. A variety of cellular and molecular mechanisms involved in the regulation of aquaporins in roots under stress have been identified. These include the gating of PIPs by cytosolic protons under anoxia, and a Reactive Oxygen Species (ROS)-dependent signalling path. The latter path is shared by salt, salicylic acid and potentially other abiotic and biotic stress-related stimuli, and involves calcium-dependent events and an internalisation of PIPs. Aquaporin post-translational modifications can be monitored by mass spectrometry-based techniques. A link between phosphorylation of a root aquaporin isoform and its subcellular localization was established in the context of salt stress.

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L 4.13 - Exploiting the genomes of dehydration/desiccation-tolerant species in crop improvement strategies Oliver M. 1(mel.oliver@ars.usda.gov), Cushman J.2, Sharp R.3, Payton P.1 1 USDA-ARS; 2 University of Nevada Reno;

3 University of Missouri. An understanding of plant responses to dehydration has important consequences for plant biology in general and direct impacts for agriculture. Over 10% of arable lands are affected by drought, declining average yields for most crops by more than 50%. Thus, improving drought tolerance is a priority area for agricultural research agencies. Understanding how plant cells tolerate water loss, as opposed to how plants limit water loss, is a prerequisite for developing novel strategies for improving drought tolerance. The focus of our work is to combine comparative “omics” and phylogenetics to identify genes and gene networks that are adaptive and central to the tolerance of cellular dehydration. This involves the use of resurrection species as models for dehydration tolerance coupled with a suite of comparative “omic” and functional analyses that allows for the phylogenetic assessment of mechanistic components related to the acquisition and expression of dehydration tolerance. Building on our transcriptomic work with a desiccation tolerant moss (Tortula ruralis) we have extend our phylogentic-based studies into the more complex resurrection plants, Selaginella lepidophylla (a lycophyte) and Sporobolus stapfianus (a grass). By utilizing sister-group contrasts, which compare sensitive to tolerant phenotypes, we are able to discern those responses that are injury related from those that are involved in the tolerance mechanisms. We can also distinguish between water deficit responses (related to water retention mechanisms) from responses related to cellular dehydration, which appear to be distinctly different. Our studies have revealed the importance of maintaining ATP levels during dehydration, new insights into the involvement of sugars in cellular dehydration tolerance, the involvement of signaling pathways in the recovery response, and the value of nitrogen storage during the drying phase. As our “omics” tool-kit becomes better developed, the functional role of individual genes and gene networks will become a major focus of the group. Our initial work in this area has focused on regulatory genes that we suspect activate entire networks of genes and gene products associated with dehydration tolerance in the land plants.

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L 4.14 - Integrating genomic, genetic and physiological approaches to study durum wheat responses and adaptations to drought in the Mediterranean Habash D.Z.1 (dimah.habash@bbsrc.ac.uk), Baudo M.1, Hindle M.2, Defoin-Platel M.2, Powers S.2, Saqi M.2, Lawlor D.1, Parry M.1, Tuberosa R.3, Bort J.4, Latiri K.5, Abdelkader A 6, Nasserlehaq N.7, Kehel Z.8, Nachit M.8

1 Centre for Crop Genetic Improvement, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK; 2 Centre for Mathematical and Computational Biology, Rothamsted Research, Harpenden, Hertfordshire

AL5 2JQ, UK; 3 Dept of Agroenvironmental Science and Technology, University of Bologna, Via Fanin, 44,40127

Bologna, Italy; 4 Departamenta de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avenida Diagonal

645, Barcelona 08028, Spain; 5 Laboratoire d'Agronomie, INRA, Laboratoire d'Agronomie, INRAT, Rue Hedi Karray 2049 Ariana

Tunisia; 6 General Commission for Scientific Agricultural Research GCSAR, Douma, Damascus; 7 National Institute of Agronomical Research, INRA Settat, Morocco; 8 Biodiversity and Integrated Gene Management, International Centre for Agricultural Research in the

Dry Areas, PO Box 5466, Aleppo, Syria. We have integrated quantitative genetics, physiological, biochemical, transcriptome, statistical and bioinformatics approaches to identify traits, loci and candidate genes controlling wheat responses and growth under drought. A mapping population of durum wheat from two breeding lines, Lahn (high yield potential) and Cham1 (drought adaptation) was studied in 27 field environments in Syria, Tunisia, Morocco and Italy over three years. Major quantitative trait loci have been identified for yield and yield stability under drought on chromosome groups 1, 4 and 7 and GxE interactions dissected. Lines showing better yield stability under drought have different root traits. Recombinant inbred lines showing stability of yield under drought were selected for transcriptome studies under controlled environment and field conditions. Pathway and network analysis of global gene expression of time-series water stress experiments has revealed a high level of structure in leaf transcript responses to water stress. Mapping to orthologous proteins and subsequently to metabolic pathways has identified genes and transcription factors involved in early and late responses to water stress. These analyses elucidate a widespread response to water stress where expression of some genes varies across time and cultivars. A systems-based approach is used to integrate the large datasets and identify mechanisms and future targets for research.

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L 4.15 - Physiological genomics of the abiotic stress response in peanut (Arachis sp.) Kottapalli K.R.1, Jones O.A.H.2, Rakwal R.3,4, Agrawal G.K.4, Shibato J.3, Burke J.7, Burow M.1,5, Puppala N.6, Payton P.7(paxton.payton@ars.usda.gov) 1 Texas Tech University, Department of Plant and Soil Science, Lubbock, Texas, USA; 2 University of Cambridge, Department of Biochemistry, Cambridge, UK; 3 National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan; 4 Research Lab. for Agriculture Biotechnology and Biochemistry, Kathmandu, Nepal; 5 Texas Agrilife Research, Lubbock, Texas, USA; 6 New Mexico State University Agricultural Science Center, Clovis, New Mexico, USA; 7 USDA-ARS Cropping Systems Research Laboratory, Lubbock, Texas, USA. Peanut (Arachis sp.) genotypes were screened for contrasting responses to slow-onset water-deficit and supra-optimal temperature. Seventy accessions were screened for basal thermotolerance, photosynthetic response, cellular damage, and recovery from stress. We selected two lines, COC041 (Tolerant) and COC166 (Susceptible), for gene expression, metabolomic, and protein profiling studies, as well as detailed physiological characterization and field trials. For transcript profiling, we have developed a high-density oligo-array representing 15,208 unique probes in an Agilent Technologies 8×15 k design. Initial analyses of gene expression changes in leaf tissue revealed significant differences between tolerant and susceptible germplasm. A total of 623 transcripts showed genotype-specific expression patterns and are currently being analyzed. One- and two-dimensional gel electrophoresis (1- and 2-DGE) was performed on leaf soluble protein extracts from the same, stressed and control plants. A total of 23 and 79 protein bands/spots from 1-D and 2-D gels, respectively, were analyzed by MALDI- TOF MS and by MS/MS analysis. Forty-nine non-redundant proteins were identified implicating a variety of water-deficit stress response mechanisms in peanut. Specifically, there was a marked decrease in the abundance of several key photosynthetic proteins in the tolerant and moderately tolerant genotypes which corresponded with a rapid decrease in photosynthetic capacity. Interestingly, the tolerant genotype exhibited a more rapid decline in photosynthetic rate and conductance but a significantly faster recovery of photosynthetic capacity upon re-watering or return to ambient growth temperature. Metabolomic studies are currently underway and will be reported at this meeting.

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L 5.01 - Epigenetic and genetic control of drought tolerance in rice Li Z. K. (lizhk@caas.net.cn) CAAS

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L 5.02 - The problems and strategies on developing drought resistance rice varieties Luo L. J. ( lijun@sagc.org.cn), Yu X.Q., Feng F.J., Song J.Q., Lou Q.J., Li M.S., Liu H.Y., Mei H.W., Chen L. Shanghai Agrobiological Gene Center, Shanghai 201106, China. Rice is one of the most important food crops in the world but the rice production consumed about 50% of total fresh water resources and affected easily by drought especially in the rainfed area. In addition, rice cultivation with water layer in irrigated area not only is profuse in fresh water but also resulting in the increasing environmental pollution. To achieve long-term food security and sustainable development, developing the drought resistant (DR) rice cultivars are urgently needed. Drought resistance of plant is extremely complex reflecting the ability of survive and production of plant in water stress. Up to now, a lot of drought related genes were cloned and individual gene showed positive effects under controlled stress experiments, but were not so effective in the field (Pennisi et al. 2008 Science 320:171-173). However, the progresses by conventional breeding approaches were achievable. In our group, several drought resistant cultivars were developed and released to the farmers. A DR rice variety, IRAT 109, was used as DR parent to construct a RIL mapping population, as well as to develop DR CMS line through backcross breeding based on phenotypic selection under severe water stress condition. The primary results indicated that there is 5.36% polymorphism between the DR CMS line Huhan 2B and its recurrent parent Hanfeng B based on 1343 SSR and Indel markers. A total of 72 polymorphic markers distributed among 11 of 12 rice chromosomes. Only two marker intervals were collocated with the QTLs found in the mapping experiments(Zou et al, 2005). There were great diversity of the SOD, OA, morphological traits and tissue structure among the 200 rice germplasm accessions which were screened out showing some degree of drought resistance. It is very difficult to put so many diverse genes together based on the individual gene discovery and transferring, or by pyramiding approaches suitable for several genes. Our breeding experiments indicated that the conventional breeding screen in extremely water stress environment is effective to combine the DR related genes. The materials developed by this approach showed obvious drought resistance though we did not know its genetic basic yet. A bridge between functional genomics and conventional breeding should be set up.

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L 5.03 - Fine-mapping candidate genes for ‘stay-green’ in sorghum: Are we there yet? Borrell A.K.1(andrew.borrell@dpi.qld.gov.au), Jordan D.R.1, Jaeggli B.G.1, Hammer G.L.2, Oosterom E.V.2, Klein P.3, Mullet J.3 1 Queensland Primary Industries & Fisheries, DEEDI, Hermitage Research Station, Warwick QLD 4370,

Australia; 2 The University of Queensland, School of Land, Crop and Food Sciences, Brisbane, QLD 4072, Australia; 3 Texas A & M University, Institute for Plant Genomics & Biotechnology, College Station, USA. Discovering candidate genes associated with the ‘stay-green’ drought adaptation trait in sorghum is the focus of an international research partnership between Australian (QPIF) and US (Texas A&M University) scientists. Stay-green, defined as the retention of green leaf and stem during the grain filling period under water-limited conditions, has been selected by sorghum breeders for more than 25 years. Under water-limited conditions, a stay-green phenotype will arise when the balance between the supply and demand of water for crop growth is favourable. This can be achieved by increasing the supply of water, reducing the demand for water, or a combination of both. The stay-green phenotype observed after anthesis is the emergent consequence of physiological processes initiated prior to anthesis. In general, stay-green is largely a constitutive trait in that the plants are equipped for the challenge of drought before the onset of the stress, although there are some adaptive components. Stay-green was initially mapped to four chromosomal regions (Stg1, Stg2, Stg3, and Stg4) by a number of research groups in the US and Australia. Each of these stay-green QTLs, to varying degrees, individually reduces post-anthesis drought-induced leaf senescence, for example through greener leaves (higher specific leaf nitrogen) at anthesis (Stg1 and Stg4), delayed onset of leaf senescence (Stg2, Stg3 and Stg4), reduced rate of leaf senescence (Stg1, Stg2, Stg3 and Stg4), and more green leaf area at maturity (Stg2). More recently, these regions have been fine-mapped to identify candidate genes controlling stay-green. Critical to the success of fine-mapping is accurate phenotypic and genotypic screening and, ultimately, the alignment of phenotypic and genotypic data to locate the candidate gene(s). Success in fine-mapping depends on a number of key factors, including choice of suitable parents to develop appropriate populations, the creation of managed drought environments, the selection of a small number of parameters associated with the causal mechanism rather than the consequence, and the use of appropriate statistical procedures to enhance gene discovery. The value of these candidate genes, individually and in combination, in a range of target environments, will be assessed using simulation modelling. Improved understanding of the genes underlying drought adaptation, and their interaction with management practices and the environment, should assist sorghum breeders to develop germplasm that is better adapted to our water-scarce planet.

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L 5.04 - Epigenetic mechanisms associated with drought tolerance in the desert plant Zygophyllum dumosum Boiss Granot G., Sikron-Persi N., Gaspan O., Florentin A., Talwara S., Paul L.K., Morgenstern Y., Granot Y., Grafi G. (ggrafi@bgu.ac.il) French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion 84990, Israel. Zygophyllum dumosum Boiss. is a perennial Saharo-Arabian phytogeographical element and a dominant shrub on the rocky limestone southeast-facing slopes of the Negev desert. The plant is highly active during the winter, and semideciduous during the dry summer, that is, it sheds its leaflets, while leaving the thick, fleshy petiole green and rather active during the dry season. Being resistant to extreme perennial drought, Z. dumosum appears to provide an intriguing model plant for studying epigenetic mechanisms associated with drought tolerance in natural habitats. The transition from the wet to the dry season was accompanied by a significant decrease in nuclear size and with posttranslational modifications of histone H3 N-terminal tail. Dimethylation of H3 at lysine 4 (H3K4) – a modification associated with active gene expression – was found to be high during the wet season but gradually diminished on progression to the dry season. Unexpectedly, H3K9 dimethylation and trimethylation as well as H3K27 di- and trimethylation could not be detected in Z. dumosum; H3K9 monomethylation appears to be prominent in Z. dumosum during the wet but not the dry season. Contrary to Z. dumosum, H3K9 dimethylation was detected in other desert plants, including Artemisia sieberi, Anabasis articulata and Haloxylon scoparium. Taken together, our results demonstrate dynamic genome organization and unique pattern of histone H3 methylation displayed by Z. dumosum, which could have an adaptive value in variable environments of the Negev desert.

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L 5.05 - Improving crop productivity in water-limiting environments: translational research for sustainable agriculture Heard J. (jacqueline.e.heard@monsanto.com) 700 Chesterfield Parkway West, Chesterfield, MO 63017, USA. Efficient use of water in agricultural production will be one of the great challenges during the 21st Century, with agriculture currently being responsible for ~70% of freshwater withdrawal. As such, yield improvement through tolerance to water deficits that occur routinely in the Central Corn Belt and frequently in western states are an important challenge in the coming decade. Benefits of improving water utilization efficiency, in addition to higher yield, are expected to include reduced water consumption and environmental sustainability. Genomic and systems biology approaches are adding to our understanding of plant pathways that are important to water stress tolerance. Transgenic approaches have identified genes that effectively confer drought tolerance in both models and crops such as corn. This presentation will illustrate out ability to uncover novel drought protection mechanisms using genomics and will highlight data from crops that demonstrate the enormous opportunity that exists for the application of genomics to product development.

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L 5.06 - Metabolomic and proteomic analysis of soybean root system responses to water deficits Valliyodan B.1(valliyodanb@missouri.edu), Xu D.2, Stacey G..1, Nguyen H.T.1 1 National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri,

Columbia, MO 65211, USA; 2 Computer Science Department, University of Missouri, Columbia, MO 65211, USA. Profiling soybean proteins and metabolites will lay the foundation for a systems biology approach to understand the key processes such as growth characteristics, stress responses, seed composition and yield. It is well known that the environmental cues influence developmental phenotypes in plants. Thus, by studying the gene products, a direct correlation between stress response and specific proteins/peptides/metabolites can be made. This will lead to crop improvement either through breeding or transgenic efforts. Major focus of our research is to build a comprehensive map of proteins and metabolites for soybean and help make connections between regulatory or metabolic pathways not previously characterized. Drought is one of the major abiotic stresses causing yield reduction and poor seed quality in soybean. The root system plays specific roles in stress tolerance mechanisms in plants. Soybean Willimas 82 was grown in controlled conditions and the water deficits were imposed by withholding water starting from three weeks after germination (vegetative stage V3). The stress levels were monitored by several measurements including RWC and water potential. Root tip (5cm) and leaf tissues were collected at specific stress conditions. Total protein and metabolites were isolated using standard procedures. We have utilized LC/MS approach for protein identification and GC/MS, LC/MS and NMR approaches to identify metabolites and key molecules for further characterization. We have identified several root related and stress specific proteins and metabolites, which help us to understand the biochemical networks involved in stress responses. For example, one of the drought inducible proteins, Abscisic stress ripening (ASR) proteins responds to drought through two specific functions. The first function comes from the high hydrophilicity of this protein that help in the enhanced water-retaining ability. Secondly, ASRs act as regulatory proteins involved in the ABA signaling pathway under water deficit conditions. The status of proteomics and metabolomics approaches on stress responses, analytical methodologies, experimental results, and the associated biochemical regulatory networks will be presented.

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L 5.07 - ABA regulates plant development Hua H.P., Wang L., Liu Y., He J.N., Duan Y., Liao H., Yin H.B., Gong Z.Z. (gongzz@cau.edu.cn) State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China. The plant hormone abscisic acid (ABA) mediates a variety of developmental processes including seed germination and seedling growth. However, the key factors for ABA regulating plant development are largely unknown. Screening for abscisic acid (ABA) overly sensitive mutants in Arabidopsis has identified several mutants which show enhanced ABA sensitivity in root growth and seed germination. We have identified several genes from these mutants. Genetic and molecular analyses suggest that the signals from mitochondria and crosstalk between auxin, brassinosteroids, ethylene, and ABA exist for ABA-mediated plant development.

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L 5.08 - Genetic dissection of QTL for RWC, RWL and CTD associated with drought tolerance in wheat Yang D.L.1,2, Jing R.L.2(jingrl@caas.net.cn), Li W.1, Chang X.P.2

1 National Key Facility for Crop Gene Resources and Genetic Improvement / Key Laboratory of Crop

Germplasm and Biotechnology, Ministry of Agriculture / Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China;

2 College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070, China. Doubled haploid lines (DHLs) previously constructed by a cross between Hanxuan 10, a drought tolerant cultivar, and Lumai 14, a high-yield cultivar in well-watered field, and recombinant inbred lines (RILs) previously obtained by single-seed descent (F7) from the cross between Opata85, a Mexican wheat cultivar, and W7984, an amphi-hexaploid cultivar, were selected as experiment materials in this study. Some important traits associated with drought tolerance including the leaf relative water content (RWC), the rate of excised-leaf water loss (RWL) and the canopy-air temperature difference (CTD) from two wheat populations were investigated in different locations under two water regimes (drought and well-watered condition). And, QTL (quantitative trait loci) mapping and QTL × water environment interactions (QEIs) were analyzed for these target traits in present study. The detailed results were obtained as follows: Major QTLs for RWL, RWC and CTD were mainly distributed on chromosomes 1D, 2A, 2B, 3B, 3A, 3D, 4A, 5A, 4B, 5D, 6B, 6D, 7A and 7B in DHLs and RILs. Some co-located QTLs for RWL were found in specific intervals XGli1～XksuD14.1 on 1D, Xgwm610～Xgwm397 on 4A, Xgwm193～P3470-210 on 6B and XksuG48～Xfba187 on 6D, respectively. And, one major QTL for RWC, QRwc.cgb-2B-2, as well as one major QTL for CTD, QCtd.cgb-4B, were respectively detected in the interval Xcdo678～Xcmwg660 on 2B and Xgwm495～Xgwm149 on 4B in 2005 and 2006. Two major QTLs, QRwl.cgb-6B-1 and QRwc.cgb-3B-1 were investigated the significant additive QEIs (A-QEIs) with rainfed environments, explaining phenotypic variation of 10.55% and 9.15%, respectively. Among epistatic QTLs, one pair for RWC on 2D-7B and two pairs for CTD on 2B-3B and 1D-7B showed higher phenotypic variations explaining with 22.15%, 12.67% and 13.19%. Moreover，the epistasis and the epistatic QEIs (E-QEIs) showed higher phenotypic variations, indicating that epistasis and E-QEIs significantly affected the inheritances for three target traits.

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L 5.09 - Fine mapping of two major durum wheat QTLs for grain yield identified under different water availabilities Maccaferri M.1, Aloisio I.1, Paux E.2, Salse J.2, Faure S.2, Sourdille P.2, Feuillet C.2, Corneti S.1, Sanguineti M.C.1, Demontis A.3, Massi A.3, Graziani M.1, Tuberosa R.1(roberto.tuberosa@unibo.it) 1 Agroenvironmental Sciences and Technology Dept., University of Bologna, Bologna, Italy; 2 INRA/UBP UMR 1095, Clermont Ferrand, France; 3 Società Produttori Sementi Bologna (PSB), Argelato (BO), Italy. Most of the durum wheat (Triticum durum Desf.) growing areas in the Mediterranean Basin suffer from water scarcity and erratic rainfall patterns. Therefore, identifying chromosome regions influencing yield and morpho-physiological traits related to drought response is an important objective of durum breeding. Grain yield (GY) QTLs with sizeable effects across a range of water availability (limited QTL x E interaction) would facilitate marker-assisted selection and, eventually, QTL cloning. Within the framework of the EU funded IDuWUE project, 249 RILs from the Kofa x Svevo (KS) cross were field evaluated over two years (16 environments with water availability to the crop ranging from ca. 100 to ca. 450 mm). Average GY ranged from ca. 58.8 to 5.6 q/ha in the most favourable and severely stressed environment, respectively. Two major epistatic QTLs on chr. 2BL and 3BS (QYld.idw-2B and QYld.idw-3B) influenced GY, plant height, peduncle length, SPAD and thousand kernel weight, but not heading date. QYld.idw-2B mapped to the distal region of the chromosome (Xwmc361, Xgwm846 and Xgwm1027), while QYld.idw-3B to a 6 cM interval flanked by Xgwm1034 and Xgwm493. Both QTLs were detectable in seven environments and their R2 values calculated using average GY were ca. 17%; a similar R2 value was due to epistatic effects. The presence and the effects of these two QTLs were fully confirmed by field trials evaluating a subset of 40 RILs chosen on the basis of the haplotypes at the two relevant chromosome regions. In the FP7 EU-funded project TriticeaeGenome, the QYld.idw-3B is being fine mapped through the development of sequence-based molecular markers and specific near-isogenic stocks. Fourteen pairs of heterogeneous inbred families (HIFs) with the two contrasting parental haplotypes at the 3BS confidence interval have been derived from four KS heterogeneous lines. Additional markers have been added to this interval using sequence-derived SSRs and ISBP markers obtained from BAC end-sequences. The screening of ca. 140 BES derived-SSRs allowed us to map 16 new BAC-anchored SSR markers (Cft series). QTL analysis carried out with IDuWUE phenotypic data allowed us to localize the QTL peak in respect of the chr. 3BS physical map framework. As to QYld.idw-2B, 9 SSRs have been added to the local map. HIFs will be derived also for this QTL. Up to now, the two QTL regions have been marker-enriched at a resolution of ca. 1 cm.

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L 6.01 - Water-use efficiency in wheat – the use of surrogate traits for breeding improved biomass and yield under drought Rebetzke G.J(Greg.Rebetzke@csiro.au). 1, Condon A.G.1, Farquhar G.D.2, McIntyre C.L.3, Richards R.A.1 1 CSIRO Plant Industry, PO Box 1600, Canberra ACT; 2 Australian National University, PO Box 475, Canberra ACT, Austrialia; 3 CSIRO Plant Industry, QBP, Austrialia 306 Carmody Rd, St Lucia QLD, Austrialia. Yield gains in dry, rainfed environments are difficult to achieve through breeding. This reflects drought as a dynamic entity changing in timing and severity from one year/site to the next. Differential canopy growth and subsequent water use across variable environments contributes to large genotype × environment interaction to reduce repeatability of genotype performance and confidence in selection. There is potential to improve yield performance by complimenting conventional selection for yield with selection for physiological traits. Drought results in reduced yield through lowered harvest index and biomass production and lowered harvest index, indicating two broad avenues for improving yield under drought – improving partitioning of assimilate to boost grain number and/or size and increasing crop biomass. Water-use efficiency (WUE = biomass ÷ water used during growth) is genetically correlated with improved biomass and yield under drought. Understanding of rainfall and water availability across contrasting agroecological environments has identified different crop features contributing to increases in WUE. For example, transpiration efficiency (TE), the ratio of net photosynthesis to water transpired, is an important component of WUE in environments where stored soil water accounts for a major portion of crop water use. Carbon isotope discrimination (Δ), through its negative relationship with transpiration efficiency, has been used in selection of higher wheat yields in breeding for rainfed environments. Use of Δ has potential in breeding programs as it both integrates TE over the period in which dry matter is assimilated and is simple to measure on large numbers of families. There is considerable genetic variation for TE within reach of most commercial wheat breeding programs. The challenge for breeders is to identify among parents and progeny lines with high TE using Δ or meaningful surrogates for components of TE. Opportunities for selection of progeny using molecular (QTL) and physiological markers (e.g. stomatal conductance, canopy temperature, leaf N and leaf/grain Δ) will be discussed. Particular attention will be given to the potential trade-off between water-use and growth, and the impact this may have on choice and timing of phenotyping of TE surrogates in breeding populations.

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L 6.02 - Using information from managed-stress drought environments in practical cultivar development and drought tolerance gene detection Atlin G.N.1 (g.atlin@cgiar.org), Araus J.L.1, Kumar A.2, Ramaiah V.3, Bernier J.4, Zhao D.2, Yan J.1, Bänziger M.1 1 CIMMYT, Apdo. Postal 6-641, 06600 Mexico, D.F., Mexico; 2 IRRI, DAPO 7777, 1301 Metro Manila, Philippines; 3 AVRDC, PO Box 42, Shanhua, Tainan 74199, Chinese Taipei; 4 Mycogen Seeds, 19 Hua'ai Rd., P.O. Box 339, Hoolehua, HI 96729, USA. Screening for drought tolerance (DT) means evaluating genotypes, alleles, or transgenes for yield under conditions analogous to natural stress in the target population of environments (TPE). By definition, droughts are unpredictable, causing practical problems in developing screens. Breeders and geneticists must (1) ensure that values of genotypes or alleles estimated in screens are predictive of those under natural stress, (2) ensure that stress means are estimated with adequate precision for selection or QTL mapping, and (3) for cultivar development, decide how to weight stress versus non-stress (and secondary trait) means in selection decisions. Large commercial breeding programs have relied on extensive multi-location testing, identifying DT cultivars at locations with natural drought stress. This ensures that over many years, relevant stresses are appropriately represented, but is too expensive for most breeding programs, genetic analysis, and transgene evaluation. The CIMMYT maize and IRRI rice breeding and drought genetics programs rely mainly on managed-stress screening (MSS) for DT in dry seasons. MSS improves reliability of stress application but introduces other problems, including screening in out-of-season conditions that are unrepresentative for temperature and daylength, generation of data out of sequence with breeding program advancement needs, and inappropriate weighting of means from stress and non-stress trials. Addressing these problems is becoming urgent in maize with the advent of genomic selection, adopted in CIMMYT’s DT breeding effort due to the highly polygenic nature of the trait and the failure to detect many useful large-effect QTL. Generally, MSS in maize and rice has proven adequately repeatable on a single-site basis, and CIMMYT and IRRI breeding programs have demonstrated that gains in DT from MSS are expressed in the TPE. However, empirical evidence on genetic correlations between traits in MSS at particular sites and in the TPE is urgently needed. Large-effect QTLs influencing yield under stress have been detected in MSS in rice, usually with greater precision and at lower cost than that for QTLs affecting other drought-related traits. The IRRI drought genetics program has been successful in identifying and coarse-mapping such QTLs, and in physiological analysis and elucidating the basis of allele effects on yield. Fine-mapping and cloning of these loci must be accelerated. For this, facilities permitting more reliable and precise phenotyping are needed.

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L 6.03 - Evaluation of cotton near-isogenic lines introgressed with QTLs for drought resistance Levi A.1, Paterson A.H.2, Saranga Y.1(saranga@agri.huji.ac.il)

1 The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of

Jerusalem, P.O. Box 12, Rehovot 76100, Israel; 2 Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA. The efficiency of marker assisted selection (MAS) for improvement of simply inherited traits is gaining an increasing recognition, however, there are hardly any examples of successful MAS for complex polygenic traits, such as yield and drought resistance. Quantitative trait loci (QTLs) for yield and drought related physiological traits (osmotic potential, carbon isotope ratio - an indicator of water use efficiency, and leaf chlorophyll content), were exchanged via MAS between elite cultivars of the two cotton species Gossypium barbadense and G. hirsutum. The resulting near isogenic lines (NILs) were examined under field conditions to test the efficiency of MAS for improving cotton productivity under drought conditions and the underlying physiological traits. NILs introgressed with QTLs for high yield rarely exhibited an advantage in yield relative to the recipient parent, whereas a considerable number of NILs exhibited the expected improvements in term of osmotic adjustment, carbon isotope ration and leaf chlorophyll content. Moreover, a few NILs exhibited modifications in non-targeted traits such as greater photosynthetic capacity under severe drought, modified leaf morphology and considerable changes in metabolic and mineral profiles. We conclude that MAS is a useful approach to enhance drought-adaptive traits in cotton, but complimentary conventional breeding is necessary to combine the introduced QTL(s) with high yield potential.

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L 6.04 - Bread wheat and cyclical drought: the genetics and traits behind productivity Bennett D.1,2 (dion.bennett@ausgraintech.com), Reynolds M.3, Mullan D.3, Izanloo A.1,4, Kuchel H.2, Langridge P.1, Schnurbusch T.1,5

1 Australian Centre for Plant Functional Genomics, PMB 1, Glen Osmond, South Australia, 5064, Aus-

traila; 2 Australian Grain Technologies, Perkins Building, Roseworthy Campus, Roseworthy, South Australia,

5371, Austraila; 3 International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, 06600 Mexico,

D.F., Mexico; 4 Department of Agronomy and Plant breeding, Faculty of Agriculture, University of Birjand, Southern

Khorasan, Iran; 5 Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, D-06466 Gatersleben, Germany.

Bread wheat is an important crop internationally due to its contribution to human nutrition. Locally, bread wheat is the most widely grown crop and contributes significantly to Australia’s world trade. However, cyclical (intermittent periods of water stress occurring pre- and/or post-anthesis) and terminal drought, as well as increasing temperatures, are prominent features of the Mediterranean climate and can have a significant effect production. Progress within traditional breeding programs for tolerance to abiotic stress such as drought and heat is slow due to its complex genetic basis and the significant interaction with environment. To date, relatively few studies have been conducted in wheat to genetically dissect tolerance to drought. RAC875, a locally adapted bread wheat breeding line that is considered tolerant of drought and heat stress, was crossed with Kukri, another locally developed cultivar, less tolerant than RAC875 to the two stresses. A doubled haploid population was subsequently produced, with 368 lines. From 2006 to 2008, the population was grown across southern Australia in 13 year*site combinations, as well as in Obregon, Mexico in three fully irrigated trials and one drip irrigated drought treatment trial. Extensive data sets were collected from all sites, with traits measured including morpho-physiological traits such as leaf glaucousness, tiller number, flag leaf dimensions and water soluble carbohydrates. Key yield components such as 1000 grain weight were also measured. A number of traits contributing to superior grain production within this population under water limited conditions were identified, including flag leaf width and seed number per spike. While phenology is one of the major factors driving productivity in this environment, greater flag leaf width appears to contribute to the superior grain size of RAC875. Furthermore, the ability of RAC875 to maintain a greater number of grains per spike increased yield through improving grain number per m2. A key QTL on chromosome 6A, not coincident with a maturity effect, accounted for up to 16% of genotypic variation for flag leaf width and 18% of 1000 grain weight, with the RAC875 allele favorable in all environments. An additional QTL on chromosome 7A accounted for up to 16% of genotypic variation for seed number per spike and up to 17% of grain yield, with the RAC875 allele conferring a greater than 10% yield advantage in four of the southern Australia trials. Based on previously published findings, we expected leaf glaucousness to confer a yield advantage in this population, but this was not the case. This investigation has improved our understanding of traits behind bread wheat performance in the challenging wheat production environment of southern Australia.

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L 6.05 - Integrating molecular markers into wheat improvement under water-limited conditions Jing R.L. (jingrl@caas.net.cn) The National Key Facility for Crop Gene Resources and Genetic Improvement / Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Wheat (Triticum aestivum L.) is the staple food crop for about 35% of the world population, but usually suffers drought stress in water-limited areas, which strongly reduces the production. More than 6,667 000 ha of rainfed wheat are grown in arid and semi-arid areas with low and unstable yield in China. Developing wheat cultivars with improved drought tolerance (DT) is an efficient way to stabilize production and alleviate food insecurity in China and the world. However, the genetic improvement of DT is a challenge task because of the complexity of drought tolerance in crop plants, environmental factors and their interactions. Conventional breeding approach has play a big role in drought tolerance improvement, whereas can not meet the increasing demand. Recent advances in molecular markers may provide powerful tools for the genetic dissection of DT components and improvement by marker-assisted selection. We will introduce the development of DT molecular markers based on the linkage mapping, association mapping, and functional markers. The perspective of integrating MAS tools with the conventional breeding techniques for drought-tolerant improvement of wheat will also be prospected.

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L 6.06 - Genetics, physiology, breeding and multi environment testing of a major QTL contributing to yield of pearl millet in drought stress environments Yadav R.S.1 (rsy@aber.ac.uk), Sehgal D.1, Nepolean T.2, Vadez V.2, Hash C.T.2, Sharma P.C.3, Khairwal I.S.4

1 Institute of Biological, Environmental & Rural Sciences (IBERS), Aberystwyth University, Gogerddan,

Aberystwyth, SY23 3EB, UK; 2 International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Patancheru, 502 324, Andhra

Pradesh, India; 3 Central Soil Salinity Research Institute (CSSRI), Karnal, 13200, Haryana, India; 4 All India Coordinated Research Project (AICRP) on Pearl Millet, Mandor 342304, Rajasthan, India. Pearl millet [Pennisetum glaucum (L.) Br.], belonging to family Poaceae, is the staple cereal grain and fodder crop grown by subsistence farmers in the hottest, driest regions of sub-Saharan Africa and the Indian subcontinent. It is largely grown as a rainfed crop in these regions where post-flowering drought stress reduces its yield and yield stability drastically. Improving the adaptation and (or) tolerance of pearl millet to drought stress is, therefore, a major objective in most pearl millet breeding programmes. This presentation will review the genetic and genomics resources that have been developed in pearl millet over the years and how they are being utilized in dissecting and breeding of increased drought tolerance in this crop. It will particularly focus on the identification and validation of a major quantitative trait locus (QTL) of terminal drought tolerance mapping to linkage group 2, which explained up to 32% of variation in grain yield under multi-environment terminal drought screening using two independent crosses. Results will be presented on the genetics and physiology dissected of this QTL, as well as on successes of its marker-assisted breeding in to elite pearl millet hybrid parental lines. Results will also be presented of the evaluation of near-isogenic line hybrids of this QTL in different agro-climatic zones of India and sub Saharan Africa differing in terms of intensity and duration of drought and also of their evaluations under saline conditions. The on-going efforts towards delimiting the interval of mapping of this QTL (using a high resolution cross segregating only for the QTL region on LG 2 and targeted association genetics analysis using global collection of pearl millet germplasm), and towards the development of gene-based markers (using comparative mapping approaches) closely associated with this QTL will be discussed in the context of breeding pearl millet cultivars adapted to Indian and sub-Saharan African conditions.

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L 6.07 - Wheat yield and water use: what do they have to do with carbon isotope discrimination? Condon A.G.1 (tony.condon@csiro.au), Kirkegaard J.A.1, Rebetzke G.J.1, Farquhar G.D.2, Richards R.R.1

1 CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia; 2 Australian National University, Research School of Biological Sciences, Canberra, ACT 0200, Australia. In several glasshouse studies, plant transpiration efficiency (TE = biomass/transpiration) has been shown to be negatively correlated with carbon isotope discrimination (13C), as predicted by theory. This has led to the proposition that selecting for low 13C may improve yield in dry environments. But among wheat and barley cultivars grown in rainfed environments, many studies have found that higher grain yield is actually associated with high grain-13C. Interestingly, very few of these studies have actually reported crop water use. Here, we investigate the important yet apparently contradictory observation that yield and grain-13C are positively correlated, using data on seasonal courses of wheat growth and water use, and changes with time in plant water relations, gas-exchange, isotopic compositions of C and O, and of stem water soluble carbohydrates. We conclude that, often, instantaneous leaf TE, reflected in leaf-13C, is actually positively correlated with yield and crop WUE (yield/evapotranspiration) in rainfed environments. This is due to pleiotropic effects on rate of growth associated with high TE and to the relationship between crop growth rate and the seasonal courses of vapour pressure deficit and evaporation of water from the soil surface. The relationship of yield with grain-13C is further complicated because 13C of grain may reflect not just variation in instantaneous TE but also (1) access to sub-soil water which also contributes to higher yield, and (2) remobilisation to the grain of stored assimilates acquired before grain-filling. From plant breeding, molecular-marker develop- ment and gene-discovery perspectives, it would be very useful if these various contributions to grain-13C and to grain yield could be dissected. Stable isotope analysis may assist in this dissection.

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L 6.08 - Development and release of drought resistant aerobic rice ‘ARB 6’ in India Shashidhar H.E.1 (heshashidhar@rediffmail.com), Himabindu K.1, Manjunatha K.1, Dhananjaya R.1, Vinod M.S.1, Sharma N.1, Janmatti M.1, Venuprasad R.1, Kanbar A.1, Raghu1, Chandrashekara S.C.1, Devi V.1, Ramachandrapa B.K.1, Prakash N.B.1, Sridhar C.J.1, Verulkar S.2, Atlin G.3, Manohar K.1, Lakshmipathy4, O’Toole J.C.5 1 University of Agricultural Sciences, Bangalore, Karnataka, India; 2 IGKV, Raipur, Chhattisgarh. India; 3 IRRI, Philippines/CIMMYT, Mexico; 4 Farmer, Bangalore, India; 5 The Rockefeller Foundation, USA. Drought resistance is a complex trait but significant improvement has been made by adopting rigorous/innovative selection schemes and well-established conventional breeding approach. In this paper, we describe development of a drought resistant rice variety at UAS, Bangalore. Herein drought resistance is manifested as highest grain yield under severe stress. An innovative selection methodology has been adopted in the breeding program to develop this drought resistant rice variety. A local variety Budda, has been used as a female parent and IR64, as male. F2 onwards, segregants were screened under severe-stress and for productivity under well-watered conditions during dry season, and grown under well-watered condition only during rainy season respectively. Irrigation water was 40 and 20% less than the evaporation from the field for the dry and the well-watered treatment respectively (during dry season). Dry-direct seeding in well-spaced lines was adopted in raising all generations thus effectively saving water invested in land preparation, puddling, levelling, nursery and transplanting. The fields were never flooded at any time during the cropping season. Selection was based on roots characters evaluated at maturity in selected families from advanced generations in polyvinyl chloride tubes filled with soil. Biomass, grain yield and harvest index were important criteria for selecting the plant under low-moisture stress compared to well-watered condition. F6 material was nominated for station trials in Karnataka and All India trails as detailed above. This variety has been evaluated across the India at six locations, in three hydrological situations at each site during the wet-season over three consecutive years. Overall means across location×year×hydrologies was 1.912 t ha-1 in severe stress, 3.82 t ha-1 under moderate stress and 4.466 t ha-1 under non-stress conditions. In contrast, IR64 yielded 0.872 t ha-1 in severe stress, 2.601 t ha-1 under moderate stress and 5.084 t ha-1 under non-stress conditions. The variety has been released at University of Agricultural Sciences, Bangalore, India and is at an advanced stage of release at IGKV, Raipur, India. The Rockefeller Foundation, USA funded the entire work over a period of twelve years.

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L 6.09 - Large-effect QTL influencing yield under water-limited conditions in rice: detection and potential use in breeding Venuprasad R.1 (venuprasad.ramaiah@worldveg.org), Atlin G.N.2, Bernier J.3, Bool M.E.4, Kumar A.5

1 AVRDC, PO Box 42, Shanhua, Tainan 74199, Chinese Taipei; 2 CIMMYT, Apdo. Postal 6-641, 06600 Mexico, D.F., Mexico; 3 Mycogen Seeds, 19 Hua'ai Rd., P.O. Box 339, Hoolehua, HI 96729, USA; 4 Monsanto Philippines, Inc., Lagao, General Santos City 9500, Philippines; 5 IRRI, DAPO 7777, 1301 Metro Manila, Philippines. Drought is the major abiotic stress limiting rice production in rainfed systems, which occupy 45% of total rice area. In spite of its importance, progress in breeding for drought tolerance in rice has been slow. One way to improve breeding efficiency is to identify QTL with large and consistent effects on yield under drought stress that could be used for marker-assisted breeding (MAB). IRRI has developed an efficient pipeline for detecting such alleles, using selective genotyping of large populations, derived from crosses between tolerant and susceptible lines phenotyped under both severe drought and non-stress conditions. To date at least four QTL with large effects on drought yield were detected. DTY1.1, a major QTL for yield under lowland drought stress near the sd1 locus in the CT9993/IR62266 population on chromosome 1 (~206 cm), explained 32% of the genetic variance for the trait over two years. This region also affects yield under drought stress in several other genetic backgrounds, including Apo/IR64, Apo/IR72, Vandana/IR64, Vandana/IR72, and IR64*2/Azucena. DTY3.1, a QTL on chromosome 3 (~192 cm), had a large effect on grain yield under severe lowland drought stress, explaining about 31% of genetic variance in an Apo/2*Swarna population. It also explained considerable variance for yield in aerobic environments (R2 =28%). This region also had effects in the Apo/IR64 and IR55419/Way Rarem populations. DTY6.1, on chromosome 6 (~21 cm), had a highly significant effect on grain yield in aerobic conditions, explaining up to 66% of genetic variance in an Apo/2*Swarna population. This region also had effects in Apo/IR64, Apo/IR72, Vandana/IR64, and Vandana/IR72 populations. In the Vandana/Way Rarem upland population, qtl12.1 on chromosome 12 (~50 cm) explained about 51% of the genetic variance for yield under severe upland drought stress over two years. In an Apo/IR64 population too this region showed a positive effect although it had no effect in several other populations. One important challenge in applying these QTL in MAB is that allele effects often differ greatly among populations. Improved understanding of physiological effects and allelic diversity at these loci is needed for effects to be predicted in other crosses. Therefore, fine-mapping and positional cloning of these alleles is urgent. However, several have already been shown to have effects in widely-grown recurrent parents such as IR64, IR72, and Swarna, and may be immediately useful in improving the drought tolerance of these important varieties. A continued effort to evaluate potential drought tolerance donors is likely to yield more such useful alleles.

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L 6.10 - Large-scale phenotyping and genotyping of global maize germplasm and integrated linkage-linkage disequilibrium mapping for drought tolerance in maize Xu Y.B.1 (y.xu@cgiar.org), Lu Y.L.1,2, Hao Z.F.3, Guimarães C.T.4, Gao S.B.2, Yan J.B.1, Zhang S.H.3, Li J.S.5, Vivek B.S.6, Magorokosho C.7, Mugo S.8, Makumbi D.8, Taba S.1, Araus J.L.1, Rong T.Z.2, Crouch J.H.1

1 Genetic Resource Program, International Maize and Wheat Improvement Center (CIMMYT), Km 45,

Carretera, Mexico-Veracruz, El Batan, Texcoco, Mexico; 2 Maize Research Institute, Sichuan Agricultural University, Sichuan 625014, China; 3 Institute of Crop Science, Chinese Academy of Agricultural Sciences, National Key Facilities for Crop

Genetic Resources and Improvement, Beijing 100081, China; 4 Embrapa Maize and Sorghum, CP 151 Sete Lagoas, MG 35701-970, Brazil; 5 National Maize Improvement Center of China, China Agricultural University, Beijing 100094, China; 6 CIMMYT Int., C/o ICRISAT, Patancheru-502324, Greater Hyderabad, (A.P.), INDIA; 7 CIMMYT, 12.5 Km peg Mazowe Road, P.O. Box MP163, Mount Pleasant, Harare, Zimbabwe; 8 CIMMYT, PO Box 1041, Village Market-00621, Nairobi, Kenya. Characterization of genetic variation and identification of genes for drought tolerance is critical for improvement of maize adaptability. A total of 550 lines representing both temperate and tropical maize germplasm were evaluated for over 60 traits at vegetative and reproductive stages under both well-watered and water-stressed conditions. These lines include 220 recombinant inbred lines (RILs) from three populations and 106 backcrossed introgression lines (ILs) from 38 IL sets. Multiple drought tolerance criteria were screened for drought tolerance, including biomass before and after the drought stress as measured using the normalized difference vegetation index (NDVI), anthesis-silking interval, leaf senescence, chlorophyll content, root capacitance, final grain yield and drought tolerance index (DTI). Heritability estimates and genetic correlation among selection criteria indicate great potentiality of using NDVI for drought tolerance screening. The 45 lines with the best level of drought tolerance produced an average of more than 700 kernels per plot (Xu et al, this conference). All the tested lines have been genotyped using two SNP chips containing 3072 single nucleotide polymorphisms (SNPs), with 2139 informative and high-quality markers selected for genetic mapping. One of the SNP chips was developed from candidate genes related to drought tolerance. By linkage mapping using the three RIL populations, 179 quantitative trait loci were identified by composite interval mapping, explaining an average of 20.1% of the phenotypic variance. By linkage disequilibrium (LD)-based association mapping using 106 ILs, 46 marker-trait associations were identified. Two candidate genes for drought tolerance inferred from two SNPs were shared by both mapping methods (Hao et al, this conference). Preliminary results from LD mapping using all 535 lines (after excluding open-pollinated varieties) identified 39 marker-trait associations involving 18 markers and 17 traits (P-marker value <10-8). Twelve of the 18 SNPs can be traced back to genes with known function, which may relate to maize drought tolerance. The average total variation explained by a marker is 7.0%, with the highest for SNP PZA03134.1 (18.1%) for DTI. Integrated linkage-LD mapping is underway and will be presented at the conference. The candidate gene-based SNP genotyping combined with the integrated linkage-LD mapping provides a powerful strategy for identifying genes associated with drought tolerance in maize.

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L 6.11 - Development of informative markers through association mapping in maize to improve drought tolerance in cereals Yan J.B. (j.yan@cgiar.org) CIMMYT

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L 6.12 - Complementary integrative genomics approach for exploring seed quality traits and yield under drought prone environment in barley Sreenivasulu N. (srinivas@ipk-gatersleben.de), Seiler C., Harshavardhan V.T., Rajesh K., Worch S., Röder M., Kumlehn J., Wobus U. Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany. Drought is one of the major environmental constraints that severely limit crop productivity especially during anthesis and seed set. Yield safety could be improved if future breeding attempts will be based on the valuable new knowledge acquired based on the processes determining developmental programs that enhance yield stability and improve grain quality under terminal drought. Setting these aims, recently we explored natural genetic variation among introgression line populations with wild barley accessions as donors in an attempt to understand mechanisms of reaching enhanced yield stability and uncompromised seed quality under drought stress during seed filling. From the evaluation of phenotypic and biochemical data the BC3 double haploid Hordeum Spontaneum 584 (BC3 DH Hs584) population containing 70 introgression lines were assessed for its performance under terminal drought, detected a total of 28 major QTLs (LOD score≥3) with the most significant Loci on chromosome 1 and 2 where several QTLs are co-localised. The better performing introgression line possessing segment of Hs584 introgression in hot spot QTL region depicting minimized yield loss under terminal drought and sensitive introgression lines with severe yield penalty under terminal drought have been selected to study differential drought responses from throughput genomics platform. It includes transcriptome, metabolome and enzymatic analyses together with sophisticated bioinformatic tools, which will enable the identification of favourable alleles and regulatory networks underlying improved performance. Also by studying the elite breeding material we dissected the regulatory and metabolic networks influencing staying green and senescence phenotypes under terminal drought and its influence on seed quality and yield. These results shed important insights into the importance of ABA role in developing seed metabolism under terminal drought. Based on these findings GMO modification is underway for 16 gene constructs to verify the possible implications of ABA role in seed for post anthesis drought tolerance. Transgenic plants are developed to manipulate the levels of ABA in source (flag leaf) and sink (developing barley grain) and to alter ABA hypersensitivity in seed tissues using a set of drought inducible promoters to study its impact on seed filling efficiency under terminal drought. Also as a proof of concept ABA content has been altered through immunomodulation by expressing antiABA antibody in source and sink tissues. In summary, these integrated approaches help us to dissect the complex molecular mechanisms of tackling tolerance to drought in the lime light of yield stability are expected to shed important information for breeding strategies.

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L 6.13 - Designing a simulation platform to study QTL detection and breeding response to selection as confounded by gene x trait x environment x management interactions Chapman S.C.1 (scott.chapman@csiro.au), Wang J.K.2, Chenu K.3, McLean G.3, Doherty A.3, Hansen N.1, Dieters M.4, Hammer G.L.4

1 CSIRO Plant Industry, St Lucia, Qld 4072, Australia; 2 CIMMYT, Beijing, China; 3 APSRU, Primary Industries and Fisheries, Toowoomba, Qld 4350, Australia; 4 School of Land, Crop and Food Sciences, University of Queensland, Brisbane, Qld 4072, Australia. With the increased availability of molecular marker and gene sequence information, a major challenge for plant breeders is how to best utilise this information to increase genetic gain. For water-limited environments, breeding decisions in QTL detection, crossing and selection, are further complicated by how yield is realised as a consequence of short-term and long-term interactions of genes, traits and environments. As in many other industries, simulation allows the testing and trialling of new methods, i.e. even before many breeding programs have the data or capability to apply such methods. To assist such decisions we utilise a platform where a genetic simulation model of gene effects and breeding schemes (Qu-Gene - www.uq.edu.au/lcafs/qugene/) interacts directly with a bio-physical simulation model (APSIM www.apsim.info). This is the first platform that accounts for the complex interplays of genetic controls, physiological traits, and environmental conditions throughout the crop cycle and the consequences for crossing and selection. This platform enables the construction of thousands of ‘desktop breeding programs’, where different parent lines, type of crosses, evaluation environments and selection criteria can be evaluated. The paper illustrates how this platform can be used to: - create complex crosses among diverse parental lines while accounting for gene linkage and additive, epistatic, environmental and error effects. - generate in silico datasets to test the impact in breeding programs of QTL for traits observed at different time or organ scales (e.g. hourly leaf growth, maximum leaf area index or grain yield). - explore the expected selection response for yield based on direct selection or indirect selection using trait-based or environment-based selection indices that aim to exploit interactions between genotype and environment.

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L 6.14 - Physiological basis of improved drought resistance in common bean: the contribution of photosynthate mobilization to grain Rao I.M. (i.rao@cgiar.org), Beebe S.E., Polania J., Grajales M., Cajiao C., García R., Ricaurte J., Rivera M. International Center for Tropical Agriculture (CIAT), A.A. 6713, Cali, Colombia. Common bean (Phaseolus vulgaris L.) is the world’s most important food legume for direct human consumption. Terminal or intermittent drought stress affects over 60 percent of the dry bean production worldwide. Development of drought adapted bean varieties is an important strategy to minimize crop failure and improve food security in bean growing regions. In the breeding program at CIAT, improving drought resistance has received attention for more than 20 years. Previous research efforts identified deep rooting ability as an important mechanism of adaptation to drought. In this paper we report mobilization of photosynthates (from leaves and stems to pods, and from pod walls to grain) as another important mechanism contributing to improved drought adaptation. Our main objective was to evaluate drought adaptation of 36 genotypes including elite lines and checks to quantify phenotypic differences in drought resistance under field conditions and to define the physiological basis for improved drought adaptation. Two field trials (36 genotypes planted with a 6 x 6 balanced lattice design with 3 replicates) were conducted at Palmira, Colombia during June to September of 2007 and 2008. Two levels of water supply (irrigated and rainfed) were applied. The rainfed treatment resulted in intermittent drought stress in both years. A number of plant attributes were measured at mid-pod filling and at harvest. Among the genotypes tested, a few elite lines were outstanding in their adaptation to rainfed (drought stress) conditions. The superior performance of these lines under drought stress was associated with higher values of leaf area index, canopy biomass and pod harvest index (dry wt of seed/dry wt of pod at harvest x 100). A few elite lines that were developed in the last few years seem to combine several desirable traits for drought adaptation such as deep rooting, efficient use of water through stomatal control and greater mobilization of photosynthates to grain.

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L 6.15 - More efficient breeding of drought resistant peanuts Rachaputi R.C.N.1 (rao.rachaputi@dpi.qld.gov.au), Wright G.C.2, Nigam S.N.3, Basu M.S.3, Cruickshank A.W.2

1 Queensland Primary Industries and Fisheries; J.B. Petersen Research Station, Kingaroy Q 4610, Australia; 2 Peanut Company of Australia; Kingaroy, Q 4610, Australia;

3 International crops Research Institute for the Semi-Arid Tropics, Patancheru, Andhra Pradesh 502 324, India; 4 Queensland Primary Industries and Fisheries, Hermitage Research Station, Warwick Q 4370, Australia. Drought is a major constraint to productivity where peanut is grown under dryland conditions. While breeding of drought-resistant genotypes by direct selection for yield can be effective for a given target environment, more rapid progress can be aided by a prior knowledge of the physiological basis of crop performance under drought conditions. A crop physiological model to analyse yield variation under water limited conditions following the framework proposed by Passioura (1977), where: Pod Yield=Water Transpired (T) × Water-Use Efficiency (W) ×Harvest Index (HI), has been used to screen world peanut germplasm at the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT) to select genotypes possessing high levels of these traits. Low cost, rapid and easily measured surrogate measures for each of these traits were developed. A large collaborative project involving breeders, physiologists and modellers between QPI&F, ICRISAT and Indian Council of Agricultural Research agencies was implemented to apply this physiological knowledge to test whether indirect selection using the trait approach could improve the efficiency of selection in large-scale peanut-breeding programs. The research found that both direct and indirect (trait-based) selection methods for yield were able to select out high-yielding genotypes under water-limited conditions. Yields were significantly (up to 30%) higher than local check varieties, suggesting that parental selection was more critical than the breeding methodology followed. Although there were small differences in the efficiency of selection between breeding approaches, there was clear evidence that the trait approach was able to identify genotypes with high levels of W, which contributed to yield benefits in diverse water-limited environ- ments. In India and Australia a number of drought-resistant peanut varieties were developed by using trait-based selection approach and are being commercially grown.

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L 6.16 - Performance of early maturing maize varieties and hybrids in drought stressed and well-watered environments Badu-Apraku B. (b.badu-apraku@cgiar.org), Menkir A., Oyekunle M., Akinwale R. Maize Program, International Institute of Tropical Agriculture, c/o IITA (UK), Carolyn House, 26 Dingwall Road, Croydon, CR9 3EE, UK. Drought is one of the major production constraints affecting maize production and productivity in the Guinea savannahs of West and Central Africa. Drought stress coinciding with flowering and grain filling periods can reduce grain yield by 50% and 21%, respectively. Maize yield can be reduced by as much as 90% if drought occurs from a few days before tassel emergence to the beginning of grain filling period. One of the strategies pursued at IITA focuses on screening of diverse maize inbred lines with desirable agronomic and other adaptive traits for tolerance to drought under induced moisture stress. The induced drought stress is achieved by withdrawing irrigation water 28 days after planting until maturity so that the maize plants rely on stored water in the soil for growth and development. Promising inbred lines selected for drought tolerance have been used for developing early maturing drought tolerant varieties and hybrids. A trial consisting of 16 early maturing open-pollinated varieties was evaluated under induced drought stress and well - watered conditions at Ikenne during the dry seasons of 2007 and 2008 as well as under terminal drought stress at Bagauda and favorable growing conditions at Zaria in 2008. A second trial composed of 121 hybrids formed from drought tolerant maize inbred lines was evaluated at Ikenne in 2008 under induced drought stress and well - watered conditions. Results of the first trial showed that TZE-W DT STR C4 was the most promising open-pollinated variety that out-yielded the reference check, AC 90 Pool 16 DT, by 19% under drought stress and 16% under well-watered conditions. In the second trial, the best three-way cross hybrid (TZEI 2×TZEI 108)×TZEI 63 out-yielded the best open-pollinated check variety, TZE Comp 3 C3 by 60% under drought stress but not under well-watered conditions. Also, three double-cross hybrids did not differ significantly in grain yields in comparison with the best three-way and single-cross hybrids under both drought stress and sufficient water supply.

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L 7.01 - Designing crops with improved water productivity by modelling G*M*E interactions Hammer G.1 (g.hammer@uq.edu.au), Oosterom V. E.1, McLean G.2, Doherty A.2, Chapman S.3, Singh V.1, Kim H.K.1, Hunt C.2, Jordan D.4

1 The University of Queensland, School of Land, Crop, and Food Sciences, Brisbane, Qld. 4072, Australia; 2 Queensland Primary Industries and Fisheries, Toowoomba, Qld. 4350, Australia; 3 CSIRO Plant Industry, St Lucia, Qld. 4072, Australia; 4 Queensland Primary Industries and Fisheries, Hermitage Research Station, Warwick, Qld. 4370, Australia. In environments (E) where the amount of available water often limits crop growth there are many plausible genetic (G) and agronomic management (M) manipulations available for improving crop water productivity and yield. Historically, major gains have been associated with combined G*M effects. For example, the continuous yield gain of maize in the US has been associated with superior genotypes being grown at higher density. However, traditional approaches to crop improvement continue to separate G (i.e. plant breeding) and M (i.e. agronomy) approaches. In this paper we use modelling of G*M*E interactions to explore integrated possibilities for improved crop design under water limitation. The nature of water-limitation experienced by a crop through its life cycle can be characterised using simulation. The intensity and timing of water shortage has major consequences on crop growth and yield. The frequency with which particular environment types occur in the target production region is critical in the design of effective G*M strategies for improved water productivity. The balance between canopy and root system development and resource (i.e. light and water) availability and capture through the crop life cycle determines the trajectory of crop biomass accumulation, water use, and yield in each of the environment types. Here we use a case study on sorghum in NE Australia where known genetic variation in tillering and root system architecture are combined with variation in row configuration and planting density in a simulation analysis of crop design. The yield trade-offs among G*M options suited to the E types most prevalent in the target region highlight the importance of production risk and expose the dilemma in seeking broad or specific adaptation in risky production environments.

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L 7.02 - Integrated approaches to crop improvement under water-limited conditions Messina C. (Charlie.messina@pioneer.com) Pioneer

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L 7.03 - Progress in phenotyping dehydration avoidance traits for drought resistance improve- ment in rice Serraj R.1 (R.Serraj@cgiar.org), Gowda V.R.P.1, Henry A.1, Shashidhar H.E.2, Chandrababu R.3, Kumar A.1

1 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines; 2 Barwale Foundation, Hyderabad, India; 3 Tamil Nadu Agricultural University, Coimbatore, India. Long-term improvement of drought resistance and water productivity in rice requires the genetic dissection of the processes underlying plant response to soil drying, water-use, and dehydration avoidance during the most critical stages of stress development. Use of the Fraction of Transpirable Soil Water (FTSW) as a soil moisture parameter and stress co-variable allows the integration of multi-location field trials with controlled-environment experiments. It also facilitates analysis of gene expression profiles related to specific phenotypic traits under drought. Combining the FTSW dry-down method with non-destructive imaging techniques for plant growth and development measurement, and dissection of yield components, allows high-throughput, field-based, and precise drought phenotyping. These methods were used for large-scale evaluation of rice germplasm collections, breeding lines, mutants and transgenic lines. Genetic sources of drought resistance have been identified and several QTLs have been characterized, with a focus on dehydration avoidance during reproductive-stage water deficit. Genetically diverse rice germplasm panels were phenotyped for allele mining and towards the application of an ideotype approach targeting root water extraction for maintaining plant growth and yield components under drought. Similarly, root traits were analyzed in sets of NILs differing in major QTLs for yield under drought. Traits related to deep rooting were found to be positively correlated to water uptake, dehydration avoidance and root growth rate at depth during progressive soil drying. This paper reviews the recent progress in understanding the physiological processes and traits involved in dehydration avoidance and growth regulation under water deficit in rice.

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L 7.04 - Identification of physiological traits to improve water capture and yield of rain-fed wheat Foulkes J.1 (john.foulkes@nottingham.ac.uk), Carvalho P.1, Kumar A.1, Azam-Ali S.1, Weightman R.2, Snape J.3

1 Division of Plant and Crop Sciences, University of Nottingham, School of Biosciences, Leicestershire LE12 5RD, UK;

2 ADAS Boxworth R & D Centre, Cambridge, CB3 8NN, UK; 3 Crop Genetics Department, John Innes Centre, Colney, Norwich NR4 7RU, UK. Worldwide, drought limits agricultural productivity more than any other single factor. Wheat provides on average one-fifth of the total calorific input of the world’s population. Since a large number of drought-adaptive responses exist in wheat it is not straightforward to prioritise their application. In this paper, the relative usefulness to plant breeders of candidate traits for drought-resistance is quantified: rooting traits, transpiration efficiency (TE), early flowering, high stem soluble carbohydrate reserves and the stay-green trait. Field experiments were carried out in Nottinghamshire, UK from 2002/3-2004/5 examining two DH populations (Beaver × Soissons and Rialto×Spark) segregating for target traits. In addition, one glasshouse experiment was carried out at University of Nottingham quantifying associations between rooting traits and water capture in single plants grown in soil columns for one durum wheat cultivar Hourani. Field results indicated TE was negatively correlated with yield under drought, implying a trade-off between TE and season-long water uptake. Whereas flowering date and stem soluble carbohydrate reserves had neutral effects, the stay-green trait was positively correlated with yield under drought (r = 0.49). The negative correlation between TE and yield implies greater access to water by roots is likely a key trait for breeding progress. Glasshouse results showed the root length density required to capture all the available soil water was 1.45 cm cm-3, and that larger investment in finer roots deeper in the profile and less proliferation in the surface layers should improve yield by accessing extra water. We presently report the development of an ideotype that could be applied to trait-based breeding under temperate terminal drought environments. In addition, the results of genetic analysis revealing putative QTLs for target traits (12/13C discrimination (grain), stem carbohydrate reserves, and stay-green) for further fine-mapping are reported.

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L 7.05 - Revealing the yield impacts of organ-level quantitative trait loci associated with drought response in maize – A gene-to-phenotype modelling approach Chenu K.1,2 (karine.chenu@dpi.qld.gov.au), Chapman S.C.3, Tardieu F.1, McLean G.2, Welcker C.1, Hammer G.L.4

1 INRA, UMR 759 LEPSE, 2 place Viala, 34060 Montpellier cedex 01, France; 2 APSRU, Primary Industries and Fisheries, Toowoomba, Qld 4350, Australia; 3 CSIRO Plant Industry, St Lucia, Qld 4072, Australia; 4 APSRU, School of Land, Crop and Food Sciences, University of Queensland, Brisbane, Qld 4072, Australia. Substantial genotype-environment (GxE) interactions make crop improvement for drought tolerance a major challenge for plant breeding. Part of the impact of drought on corn yield arises from reduction in leaf expansion that affects light interception and from reduction in silk expansion that affects grain set. Recently, quantitative trait loci (QTL) have been shown to be associated with responses of leaf and silk expansion to soil water status and evaporative demand. As part of understanding and exploiting GxE interactions for yield, we propose a modelling approach to bridge this gene-to-phenotype gap. In this study, we combined a short-term model (hourly) of maize leaf expansion that captures the effects of genetic and environmental variations, with a new model co-ordinating the development of all leaves of a plant, and the APSIM crop model which takes account of the complex plant- crop-environment interactions at a daily time scale. The integrated model adequately predicted the profile of leaf area in 12 field situations with contrasting evaporative demand and soil water conditions, and it accurately simulated biomass accumulation and yield in 3 field situations. The model was used to evaluate the influence at the crop level of previously identified QTL for leaf and silk elongation. The yield of hypothetical recombinant inbred lines (RIL) was simulated for a range of climatic and drought conditions. QTL for faster leaf elongation increased crop yield under well-watered or pre-flowering deficit conditions, but reduced yield in terminal stress environments, as such ‘leafy’ genotypes prematurely exhausted their water supply. The QTL impact on yield was substantially enhanced by including pleiotropic effects of these QTL on silk elongation and on consequent grain set. Simulations with this relatively simple model demonstrated the difficulty of interpreting the genetic control of yield at crop level. The results highlight the potential of functional whole-plant modelling for bridging the gene-to-phenotype gap and for understanding GxE interactions for complex traits such as drought tolerance.

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L 7.06 - High-throughput phenotyping Berger B.1,2,3(bettina.berger@acpfg.com.au), Rajendran K.1,2, Eddes J.2,3, Tester M.1,2,3 1 Australian Center for Plant Functional Genomics Adelaide, PMB1, Glen Osmond SA, 5064, Australia; 2 The University of Adelaide, Waite Campus, Hartley Grove, Urrbrae SA, 5064, Australia; 3 Australian Plant Phenomics Facility Adelaide, Hartley Grove, Urrbrae SA, 5064, Australia. The effects of drought stress on plant growth and development, as well as the response mechanisms that plants have evolved are complex and therefore difficult to study. The area of functional genomics has made substantial progress in recent years through the development of modern marker technologies and the generation of large mapping populations. Unfortunately, these resources are not used to their full potential because the evaluation of the actual plant performance, the phenotyping, is still labor-intensive and time consuming. Automated plant handling and 3D imaging now allows high-throughput phenotyping, helping to alleviate ‘the phenotyping bottleneck’. The Plant Accelerator at the Australian Plant Phenomics Facility (APPF) in Adelaide will contain automated weighing and watering stations, making it possible to apply a controlled water stress regime. Additionally, plant growth rate and leaf health can be monitored non-destructively through visual imaging over time. Near infrared cameras to estimate the water content, far infrared cameras to measure leaf temperature and fluorescence imaging to monitor chlorophyll status will further complement the visual imaging to evaluate plant performance and stress level over the entire course of an experiment. This will help to dissect a complex trait like drought stress response into single components that are then suitable for QTL mapping and ultimately gene discovery. Trait dissection has already been shown to be possible for another complex trait, salinity stress response, using visual imaging.

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L 7.07 - Combining facilitated and in-field screening methods for basic and application studies of drought resistance in rice Xiong L.Z. ( xionglz322@yahoo.com.cn), Ding X.P., Hou X., Ning J., Du H., Fang Y.J., Tang N., Ye H.Y., Zhu X.Y. National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China. Drought frequently occurs in late stages of growth and development of rice and causes significant yield loss. Phenotyping of drought resistance is always a big challenge for both basic studies and breeding. In the past a few years, we combined facilitated (i.e., rainout shelter) and in-field (i.e., natural drought-prone field) screening methods to conduct basic and application studies of drought resistance in rice including germplasm screening, genetic analysis, drought testing of transgenic rice for candidate genes, and molecular breeding of drought resistance. Progresses will be presented in the meeting as outlined in the followings. (1) Germplasm screening. More than 10000 T-DNA insertion mutant families and about 200 condensed core collection of rice germplasms have been screened under drought conditions at vegetative or reproductive stages. A few mutants that were more sensitive or tolerant to drought stress than the wild type have been identified, and a few drought resistant germplasms have been included in the breeding programs. (2) Genetic analysis of drought resistance. Based on the results of genetic mapping of drought resistance, alleles of drought resistance QTLs from upland rice IRAT109 have been introduced to the irrigated rice Zhenshan 97 by marker-assisted selection. More than 20 near isogenic lines for drought resistance-related QTLs have been generated and are under testing. (3) Genomic expression profiling. Using Affymetrix DNA chip, genomic expression profiles have been surveyed for rice cultivars under drought, cold, salt, and ABA stresses. The expression profiling data has provided very useful information for selecting candidate genes for transgenic testing. (4) Functional analysis of genes conferring stress resistance in rice. More than 100 stress-inducible rice genes have been over-expressed in rice cultivar Zhonghua 11 for testing their effect on stress resistance. A few regulatory genes have been functionally characterized. (5) Molecular breeding of drought resistance of rice. A few function-known genes were transformed into rice to identify genes conferring drought resistance at reproductive stage. Experience and perspective of genetic and genomic approaches for stress resistance improvement will be discussed in the meeting.

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L 7.08 - Quantification of root systems of field-grown wheat and barley using DNA technology Huang C.Y.1 (chunyuan.huang@adelaide.edu.au), McKay A.2, Abdoshahi R.1,3, Hall S.1, Kuchel H.4, Coventry S.5, Langridge P.1

1 Australian Centre for Plant Functional Genomics, University of Adelaide, Waite Campus, Glen Osmond, South Australia, 5064, Australia;

2 South Australian Research and Development Institute, Waite Campus, Glen Osmond, South Australia, 5064, Australia;

3 Department of Agronomy and Plant Breeding, University of Tehran, Tehran, Iran; 4 Australian Grain Technologies, PMB 1 Glen Osmond, SA 5064, Australia; 5 The University of Adelaide, School of Agriculture Food and Wine, Waite Campus, Glen Osmond,

South Australia, 5064, Australia. Drought is the main environmental constraint for cereal production worldwide. Much past research had concentrated on above-ground characteristics of plants, while below-ground characteristics were mostly neglected in crop improvement programs, mainly due to a lack of efficient and accurate phenotyping methods, and the large phenotypic plasticity. Root system architecture (RSA) determines the ability of a plant to capture available water and nutrients under drought conditions. Despite of the crucial role of RSA, we know very little about RSA of wheat and barley in relation to drought tolerance. In this report, we determined the effect of drought on root growth of wheat genotypes in both the controlled environments and field conditions. Results showed that drought reduced shoot growth by 30-40% but root growth by only 10% of the total length. The root length of <0.55 mm in diameter constitutes of approximately 90% of the total root length in both young seedlings and mature plants. Drought reduced root growth mainly in the fine roots of <0.25 mm in diameter. Therefore the growth of fine roots is the most sensitive to drought. The quantification of root length from field-grown cereal crops is problematic with conventional methods. Fine roots prone to be lost during soil washing, and preparation for root imaging also is laborious. We explored a new DNA technology for the quantification of root systems of field-grown wheat and barley. Our results showed that root DNA content was correlated well with root length in different depths of soil. Genotypic variation in RSA could be revealed using root DNA quantification. There is no root washing and imaging involved in root DNA quantification, and dead roots and the roots of other species are excluded, accuracy and efficiency are largely improved. The detail will be presented and discussed in the meeting.

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L 7.09 - New phenotyping methods for screening wheat and barley for water stress tolerance James R.1, Rahnama A.2, Poustini K.2, Sirault X.1, Furbank R.1, Munns R.1 (rana.munns@csiro.au) 1 CSIRO Plant Industry, Canberra ACT, Australia; 2 Department of Agronomy and Plant Breeding, University of Tehran, Karaj, Iran. Both drought and salinity cause an inhibition of plant growth through the reduced soil water potential. Salt in the soil generates an osmotic stress which constitutes the major limitation to growth of wheat and barley in saline soil, causing reduced leaf expansion rates and tiller formation. Stomatal conductance was shown to be a sensitive indicator of osmotic stress. Stomatal conductance response measured with a cycling porometer was used to screen for genotypic variation in durum wheat for osmotic stress tolerance. Two fold genotypic variation was found in stomatal response screens of 80 international durum wheat cultivars. The stomatal conductance response was immediate, not Na+ specific, and was maintained over a period of weeks, indicating that it was a result of the osmotic stress caused by salt around the roots and not Na+ accumulation in the roots or leaves. Higher stomatal conductance under stress was linked to higher growth rates, tiller numbers and shoot biomass, indicating the potential for new genetic gains in tolerance in durum wheat and most likely in other crop species. The screening protocol for osmotic stress tolerance relied on stomatal conductance measurements which were affected to some extent by environmental noise. As there is a strong relationship between stomatal conductance and leaf temperature, a new accurate, non-invasive, automated and high-throughput screening protocol using infra-red thermography has been developed. This new screening protocol will enable accurate and fast screening of large numbers of wheat and barley seedlings.

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L 7.10 - Composite trait scores based on physiological traits as selection indices for improved drought tolerance in wheat Ober E.S. (eric.ober@bbsrc.ac.uk), Clark C.J.A., Perry A. Rothamsted Research, Department of Applied Crop Sciences, Broom’s Barn Research Centre, Higham, Bury St Edmunds, IP28 6NP, UK. In practice, physiology-based selection techniques for improving drought tolerance (DT) in conventional breeding programmes are limited in part by the proportion of genotypic variation in DT that can be explained by a single trait. Drought tolerance index (DTI, the proportion of yield potential maintained under water-limited conditions) is conditioned by a number of morphological and physiological traits. For variable rainfall environments such as the UK, yield potential always must be considered in parallel with DT per se for varieties targeted to the UK mega-environment. To measure the extent of genotypic diversity for DT in largely UK winter wheat germplasm, we have conducted experiments under irrigated and managed drought conditions using large polytunnel rainout shelters. In 2007 and 2008, 120 genetically diverse genotypes were compared, and in 2009 a subset of 66 genotypes were examined. Entries included old and current varieties and advanced breeding lines. A battery of drought-related traits was measured to characterise the phenotypic response of genotypes to a terminal drought imposed approximately two weeks prior to anthesis. There was significant genotypic variation for nearly all traits, although correlations between individual traits and DTI were usually weak. The results were similar using an index that combines DT and yield potential. However, composite scores based on summed, standardised values for a small number of key traits explained a greater proportion of the genotypic variance in DTI. For example, the suite of traits consisting of maintenance of ear dry mass accumulation at anthesis, avoidance of early canopy senescence, flag leaf size, stomatal conductance and leaf wax load may be a good predictor of DTI (r2 = 0.40, P<0.001). The stability of this composite score was tested on the same genetic material tested in different environments and years. Relationships between traits and genotypes were analysed using multivariate tools such as GGxT biplots. In addition to these phenotypic data, lines were genotyped using markers for 11 diagnostic genes (e.g. Rht1, 2 and 1RS) and 18 drought or yield-related QTLs, 94 lines were subjected to DArT to obtain further genotypic information. These datasets can be used to discover associations between phenotypic traits and genetic markers, depending on the outcome of analyses of population structure. Discussion points are the cost-effectiveness of early stage composite score-based culling of inferior material, and how a composite trait score could be described by genetic markers. Streamlining techniques to rapidly gather high quality phenotypic data, and novel ways to interface field instrumentation with hand-held computers will be described.

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L 7.11 - Oxygen isotope enrichment (Δ18O) reflects yield potential and drought resistance in maize Cabrera-Bosquet L.1, 2, Sánchez C.2, Araus J.L.2(j.araus@cgiar.org) 1 Unitat de Fisiologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; 2 International Maize and Wheat Improvement Center (CIMMYT), El Batán, Mexico. Drought is the major factor constraining world maize (Zea mays L.) production. The increment in the summer dryness and the occurrence of extended dry periods (IPCC, 2008), expects to decrease crop productivity which would increase risk of famine. This is particularly evident in tropical areas where rain-fed maize is a staple food for millions of people. Thus, improving yield potential and drought adaptation are among the main targets in most maize-breeding programs. Measurement of stable isotopes in plant dry matter has proved a useful phenotypic tool for speeding up breeding advance in C3 crops. However, the situation in C4 crops is far from resolved, since their photosynthetic metabolism precludes (at least in maize) the use of carbon isotope discrimination. This work investigates the use of oxygen isotope enrichment (18O) as a new secondary trait for yield potential and drought resistance in maize. A set of tropical maize hybrids developed by CIMMYT was grown under three contrasting water regimes in field conditions. Water regimes clearly affected plant growth and yield. In accordance with the current theory, a decrease in water input was translated into large decreases in stomatal conductance and increases in leaf temperature together with concomitant 18O enrichment of plant matter (leaves and kernels). In addition, kernel 18O correlated negatively with grain yield under well-watered (WW) and intermediate water stress (IS) conditions, while it correlated positively under severe water stress conditions (SS). Therefore, genotypes showing lower kernel 18O under WW and IS had higher yields in these environments, while the opposite trend was found under SS conditions. This illustrates the usefulness of 18O for selecting the genotypes best suited to differing water conditions.

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L 8.01 - Genetic and genomic tools to improve drought tolerance in wheat and barley

Langridge P. (peter.langridge@acpfg.com.au) Australian Center for Plant Functional Genomics (ACPFG), The University of Adelaide, PMB1 Glen Osmond, SA 5064, Australia. Wheat and barley are relatively well adapted to moisture stress and breeding programs using conventional approaches have resulted in significant improvements in productivity in rain-fed areas. In comparison to model organisms, wheat and barley have the advantages of extensive monitoring and archiving of genotypes and associated phenotypic data and the availability of unique populations adapted to specific environments and end-uses that have resulted from a long history of selective breeding. These advantages are becoming increasing significant as analytic tools improve. However, application of markers and genomics research in wheat and barley still faces a number of serious issues. In particular, many of the key traits influencing yield are poorly understood at the physiological level, hard to reliably phenotype and the genetic control is frequently poorly understood. Improvements in the structure of populations used in genetic analysis, enhancing scale and reliability of phenotyping methods and applying new analysis procedures are starting to reveal key pathways and process involved in maintaining yield in difficult environments. This presentation will focus on wheat and barley where the genetic control of traits determining yield in water limited and low yielding environments are generally expected to be of low heritability, polygenic and many of the key loci will show epistatic rather than additive effects. Current breeding and mapping techniques make it very difficult to detect and select for these types of loci. Know confounding factors, such as maturity, height, resistance or tolerance to soil diseases, and tolerance to related stresses such as boron, acidity, salinity and nutrient deficiencies must be taken into account. In many cases the genetic control of tolerance to these factors is known so that they could be fixed in both breeding and mapping populations. Our approach has been to work with populations where both parental genotypes have good agronomic performance coupled with extensive phenotyping in reliable well characterized screening environments. In addition, new trait screening methodologies that lend themselves to large scale operations have been applied. Phenotyping has been conducted across environments where many environmental factors vary but photoperiod and vernalizing temperatures are comparable. Results now coming out of genomics studies are providing insights into stress responses and provide novel strategies to improve stress tolerance. The delivery of the outcomes from these approaches can be though improvement in conventional breeding and selection strategies or through the use of genetic engineering. In both cases some specific problems and issues must be addressed if the results of the genomic and genetic analyses are to have practical outcomes.

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L 8.02 - Laboratory to field delivery: understanding plant:soil interactions Davies B. (w.davies@lancaster.ac.uk) Ian Dodd and Sally Wilkinson, Lancaster Environment Centre, Lancaster University, Lancaster LA 14YQ, UK. Soil drying commonly limits plant productivity even when there is still a substantial amount of water in the soil. This limitation occurs, initially at least, through an impact on both carbon gain and canopy development and if we are to minimise these restrictions of growth and yielding, it is important to understand their mechanistic basis. We highlight the importance of the influence of both hydraulic and chemical limitations of functioning, growth and development of plants in drying soil and suggest that by processing and responding to these signals, plants are able to optimize growth and development relative to the amount of water and nutrient available in the soil. We propose that via enhancement or suppression of different ‘root signal’ cascades we can intervene to sustain plant yielding under different environmental stresses (Morison et al. 2007). We review the identity of signals limiting leaf conductance and leaf growth and consider prospects for manipulation of signalling, with special reference to the impact of changes in sap pH, modified fluxes of abscisic acid (ABA) and of the ethylene precursor ACC (e.g. Jia and Davies, 2007; Wilkinson and Davies, 2009). We can use both synthesis and sensitivity mutants and transgenics to investigate the genetic manipulation of signalling in agriculture but there are many other ways to modify stress signalling cascades for the benefit of crop yield. We highlight the impact of a variety of management techniques including deficit irrigation, fertilizer applications, buffer treatments and other soil management techniques. Such techniques can be operated in conjunction with plant improvement to sustain yielding and increase water use efficiency in dryland agriculture. We highlight the importance of considering the association between the soil and the plant in any plant improvement and/or management programme to manipulate plant signalling pathways. For example, free-living bacteria in the rhizosphere can modify the sensitivity of a range of plant processes to soil drying, apparently by influencing hormonal signalling. This can occur via the breakdown of growth-restricting chemical influences while other rhizobacteria can contribute extra hormones to the signalling process to overcome stress-induced limitation in the supply of growth promoting chemicals. These soil bacteria can be used to positive effect in dryland conditions most effectively in combination with deficit irrigation treatments.

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L 8.03 - Conservation Agriculture: laying the ground for increased drought resilience Govaerts B.1( b.govaerts@cgiar.org), Verhulst N.1,2, Sayre K.D.1

1 International Maize and Wheat Improvement Centre (CIMMYT), Apdo. Postal 6-641, 06600 Mexico,

D.F., Mexico; 2 Katholieke Universiteit Leuven, Department of Earth and Environmental Sciences; Division Soil and

Water Management; Celestijnenlaan 200 E, 3001 Leuven, Belgium. The overall impacts predicted by climate change models vary, but we are now locked into global warming and inevitable changes to climatic patterns that are likely to exacerbate existing rainfall variability and further increase the frequency of climatic extremes and drought. Improving food security, environmental preservation and sustainability and enhancing livelihood should therefore be the main targets of the innovators of today’s farming systems. New agricultural practices for delivery to farmers also need to improve system resilience through increased soil organic matter, improved water use efficiency, nutrient use efficiency, and increased flora and fauna biodiversity. Conservation agriculture (CA), based on minimal soil disturbance, adequate levels of ground cover by crop residues and crop rotations is a management system that achieves these goals, it results in improved soil physical and biological health, better nutrient cycling and crop growth. CA also increases water infiltration, reduces soil moisture evaporation and enhances soil penetration by roots allowing crops to better adapt to lower rainfall and make better use of the available water (both from rain and) irrigation. Water and wind erosion is also reduced by CA since the soil surface is protected and water runoff is lowered as more water enters the soil profile. CA therefore results in soils and production systems more resilient to climate variation, risk and drought. CA is creating a basis on which other important management components like disease and pest resistant varieties and improved nutrient management can be fully expressed. Integrated research and farmer participatory extension is needed to fine tune CA to specific locations and identify suitable germplasm, fertility management, weed and other biotic constraints control to convince farmers to adopt these CA-based technologies. This presentation will provide results related to the above from long-term trials (>15y) comparing different management practices in different agro-ecological zones in Mexico.

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L 9.01 - Epilogue: enhancing plant production under drought stress – what’s working and what’s not Blum A. (ablum@plantstress.com) Plantstress.com

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L 9.02 - New approaches with promise for future drought research Boyer J.S. (boyer@udel.edu)

College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE 19958, USA. Improved drought performance already accomplished by breeders and agronomists increases our confidence that combining new ideas from physiology and molecular genetics can lead to drought tolerance hitherto thought impossible. This talk highlights some of these ideas with the hope that students and young scientists might be tempted to make the attempt in our major crops. The talk is oriented toward three areas: how baseline water use may be controlled by non-stomatal means, whether water use efficiency can be further improved, and what new approaches might be used to protect grain production during drought. Emphasis will be on physiological and biochemical functions combined with molecular genetics to improve drought performance.

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P 1.01 - Suggestions on sustainable water use in North China Plain Lü L.H., Hu Y.K.2, Wang H.J.1 (nkywanghj@yahoo.com.cn) 1 Hebei Academy of Agricultural and Forestry Science, Shijiazhuang 050051, China; 2 Hebei Academy of Water Resources, Shijiazhuang 050051, China. North China Plain (NCP) is an important, yet a highly water-scarce agricultural production base in China. It produces some 22% of the nation’s wheat and 16% of its maize at present. On NCP, crop production relies largely on groundwater irrigation because nearly all usable surface waters are dammed and regulated for urban and metropolitan use. Thus, in especially the piedmont regions of Mount Taihang, water table levels have dropped on the average by more 1.0 m·a-1. Agriculture water use has been recognized as the primary factor of groundwater drawdown and the major driver influencing the regional sustainable development in NCP, since it accounts for more than 70% total water-use on the plain. Since agriculture is the biggest user of water resources and major factor influencing the regional water balance and sustainability of economy, by analyzing the macro economy, water use, and agricultural production, the development of agriculture in NCP was reconsidered in this paper. There are often suggestions of cutting down the present food production in NCP. However, these suggestions were often ignored, because the pressure on food production is so high and there is a lack of accurate prediction about China’s future ability for food production. By analysis of food production in different parts of China since 1985, surprisingly, all food increasing areas locate in the North part of China, where climate resources for agricultural production is poor. On the other hand, Yangtze river catchment and Southeast China, two areas producing 46% of China’s total food in 1985 with high solar radiation, temperature, and precipitation, did not have much increase in food production. Food production in Southeast China even decreased. Above analysis suggest that, at least in short term, China still has a big potential for grain production increase, if suitable policy is given to stimulate the production in Southeast China and farmers in Yangtze River Catchment, and the pressure on food production in NCP will be mitigated. Suitable decrease of food production and applying water-saving technologies in NCP, especially Beijing, Tianjin and Hebei Province to slow down the decline of groundwater is acceptable in terms of both local economy and China’s food supply. Moreover, reservation of water is exactly like reservation of food for much longer term, to be used under China’s population summit.

P 2.01 - Seed priming methods, a way for improving drought tolerance, winter survival and yield of barley under dryland conditions Abdolrahmani B.1 (bahman122@yahoo.com), Ghassemi – Golezani K.2 , Valizadeh M.2

1 Dryland Agricultural Research Institute (DARI), Maragheh, Iran; 2 Agronomy and Breeding Department of Agriculture Faculty-Tabriz University, Tabriz, Iran. In order to evaluate the effects of seed priming methods on improving drought tolerance, winter survival and yield of barley (var. Abidar) under dryland conditions, laboratory tests and field experiment were conducted in 2006- 2007. Laboratory tests were carried out with 21 treatments as CR design and field experiment was performed with 9 treatments as RCB design at the Dryland Agricultural Research Institute, Maragheh, Iran. In the laboratory tests, considered the seed vigor parameters. According to laboratory results, Superior treatments including hydropriming, 10% PEG, 5 mM CaCl2, 10 mM Zn, 50 mM P, 100 mM P, 10 mM Zn + 50 mM P and 10 mM Zn + 100 mM P solutions and also control (non-priming) were selected and applied on seeds which subsequently sown in the field as fall experiment. In the field experiment, seed priming improved rate and percentage of seedling emergence, ground green cover, winter survival, spikes /m2, rainfall productivity index and mean grain yield per unit area. Nevertheless, seed priming improved grain yield of barley by about 32%. In this research, for the first time proved that seed priming techniques (hydropriming, osmopriming and nutrient priming) improved winter survival (by means of improving rate and percentage of seedling emergence by about 13% and 10%, respectively and ultimately produce of vigorous seedlings before winter beginning) and drought tolerance (by means of improving ground green cover and rainfall productivity index by about 34% and 32%, respectively). These factors

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consequently caused the best use of light, soil moisture and resources by the plants produced from the primed seeds under drought and dryland conditions.

P 2.02 - Evaluation of the effect of intercropping of maize/cowpea under different densities, arrangements and fertilizer rates in semi arid areas of ethiopia Abebe G .(girma12000@yahoo.com), Nikuse O., Sahele G., Dibeba T. Melkassa Agricultural Research Center, P.O.Box 436, Nazreth, Ethiopia.

Common characteristics of different forms of intercropping are intensifying crop production and exploiting more efficiently those environments with limiting or partially limiting growth resources and leading to substantial yield advantages. To test this hypothesis, a trial was conducted at Melkassa and Shoa-robit in 2006 cropping season with the objective of determining suitable maize/cowpea density and arrangement that maximize productivity of the system and agronomically suitable NP fertilizer rates for the system, the productivity of maize/cowpea intercropping. Factorial combinations of maize/cowpea densities (PD) (100:75, 100:50, 100:25, respectively) and two maize/cowpea planting arrangements (PA): - (1:1 and 2:1 rows), and four NP fertilizer levels (FL) and sole maize and sole cowpea was laid out in a Randomized Complete Block Design (RCBD) with three replications. At Shoa-robit, biological and grain yield was affected by the combined effect of the treatments (PD, PA and FL) under intercropping and the highest grain yield of maize was obtained at (100:25 PD, N=20.5, P2O5=23 FL and 2:1 PA) and the highest yield of cowpea was recorded at (0:100 i.e. sole cowpea and recommended fertilizer rate). At Melkassa, Grain yield was affected by the combined effect of the treatments (PD, PA and FL) under intercropping and the highest grain yield of maize was obtained at (100:0 PD, i.e. sole maize with recommended fertilizer level and plant arrangement) and the highest yield of cowpea was recorded at (100:75%, N=52.5, P2O5=46 FL and 2:1 and PA). Land Equivalent Ratio (LER) also showed that there was greater yield variation between treatments at both locations. At Melkassa the highest LER (1.67) was obtained at the combination of 100:75 PD, N3=52.5, P2O5= 46 FL and 2:1 PA followed by 1.57 at 100:50 PD, N= 20.5, P2O5= 23 FL and 2:1 PA. At Shoa-robit higher LER of 1.73 and 1.53 was recorded at the treatment combination of 100:25 PD, N= 20.5, P2O5= 23 FL and 2:1 PA and 100:50 PD, N= 36.5, P2O5= 34.5 FL and 2:1 PA respectively.

P 2.03 - A new model to simulate stomatal conductance of field-grown potatoes Ahmadi S.H.1,2 (seyedhamid.ahmadi@djf.au.dk), Andersen M.N.2, Poulsen R.T.2, Plauborg F.2, Hansen S.1 1 Agrohydrology group, Department of Basic Sciences and Environment, Faculty of Life Sciences,

University of Copenhagen, Denmark; 2 Crop production group, Department of Agroecology and Environment, Faculty of Agri- cultural

Sciences, University of Aarhus, Denmark. For a long time, ecophysiological modelers have adopted the simple and empirical equation of Ball-Berry for gas exchange modeling. However, the Ball-Berry model does not include any response of plants to abiotic stress and is not suitable for diverse climates. It is believed that abscisic acid (ABA) that is produced in roots that sense the dry soil, acts as a chemical signal and cause stomata closure and eventually, reduction in stomatal conductance in drought conditions. However, leaf water potential also behaves like a hydraulic signal that regulates the stomatal conductance through mediating ABA functionality under drought conditions. Only a few studies have been done to integrate and model the influence of leaf water potential and xylem ABA concentration signals on stomatal conductance. In this study, we developed and validated a new gas exchange model that integrates the modified Ball-Berry model with the water stress factors, i.e., xylem ABA concentration and plant water status. We applied and checked the model on a series of diurnal gas exchange measurements, obtained from a semi-field study on potato that were conducted under three soil types and three irrigation approaches, namely full irrigation, deficit irrigation, and partial root-zone drying irrigation that is a novel water saving irrigation approach. Results showed

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that the new model can be parameterized to correlate well to data under different environmental conditions and could explain more than 85% of the stomatal conductance variations upon validation on independent data. Furthermore, results revealed that preferably stem water potential regulates the stomatal conductance compared to leaf water potential. This model is thought to be a universal model that can be used in modeling water and CO2 exchange successfully in the soil and plant system.

P 2.04 - Participatory selection of drought tolerant maize varieties using mother & baby methodology: a case study in the semi arid zones of the central rift valley of Ethiopia Birru G.A. (girma12000@yahoo.com), Harrun H., Mesfine T., Assefa T. Melkassa Agricultural Research Center, P.O.Box 436, Nazreth, Ethiopia. In Ethiopia, so far, maize variety selection was without much consideration of farmers’ interest. However, farmers have the ability for selecting crop varieties to suit their environ- ments. Mother and baby methodology was adopted by International Maize and Wheat Improvement Center (CIMMYT) and used as a means for obtaining farmers input and feedback on the selection of new maize varieties that are in advanced stages of development. Elite Open Pollinated Varieties (OPVs), which were under national performance test, were used. These varieties belong to the early and medium maturity group and are suited for the dry agroecologies. The result clearly showed a significant difference among both early and medium set varieties for most agronomic traits at both Wolenchiti and Melkassa. The results also revealed that farmers’ preference in some cases coincide with the breeders’ selection. However, in general farmers have shown their own way of selecting a variety for their localities. Hence, it is paramount important to include farmers in a variety selection process. The methodology used in the study was found useful to collect data and identifying new varieties for farmers use.

P 2.05 - Satellite data applications to improving crop productivity under drought-prone conditions Boken V.K. (bokenv1@unk.edu) Department of Geography and Earth Science, University of Nebraska at Kearney, Kearney, NE 68849, USA. Crop productivity depends on various factors including weather conditions, the time of planting, and the availability of surface or ground water resources. Under drought-prone conditions, the availability of water resources and hence the water-use efficiency becomes critical issues. To help improve the water-use efficiency and increase crop production, satellite data can be useful. In this presentation, potential of satellite data applications to soil-moisture estimation, rainfall estimation, crop-condition assessment, and crop-planting detection will be discussed.

P 2.06 - Water stress detection using infrared canopy temperatures for irrigation scheduling Conaty W.C. 1,2 (warren.conaty@csiro.au), Mahan J.R. 3, Neilsen J.E. 2,4, Sutton B.G. 1, Tan D. K.Y. 1 1 Faculty of Agriculture, Food and Natural Resources, The University of Sydney, NSW 2006, Australia; 2 CSIRO Plant Industry, Locked Bag 59, Narrabri NSW 2390, Australia; 3 USDA/ARS Plant Stress and Water Conservation Laboratory, 3810 4th St Lubbock, TX 79415, USA; 4 Monsanto Australia Ltd. PO Box 6051 St. Kilda Rd Central Melbourne, VIC 8008, Australia. Plant-based water stress detection tools that correlate the soil and atmospheric loads contributing to plant stress may hold potential for improved efficiencies in irrigation scheduling. One method is the monitoring of plant stress is through leaf canopy temperatures, as water stressed plants exhibit higher leaf temperatures due to reduced evaporative cooling. This research aims to describe the factors that contribute to canopy temperatures. Field canopy temperatures (CT) were monitored with the SmartCropTM infrared thermometers every 15 minutes in a cotton crop grown in Narrabri, Australia during the 2007/2008 season. Five replicate blocks of a RCBD experiment were irrigated using a surface drip irrigation system under three irrigation treatments -25%, 100% and

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125% of daily reference crop evapo-transpiration (ETo). Corresponding leaf water potential (LWP), soil moisture and climatic data were monitored to determine the basis of fluctuations in canopy temperatures and the necessity of irrigation. There was a linear relationship between CT and LWP on the combined data (P<0.001 and R2=0.76). When vapour pressure deficit, radiation and soil water were included in the regression analysis the variation in the data decreased (R2=0.86). All data points from the 100% and 125% treatments LWP did not exceed stress levels (> -20 bar). Similarly, only 23% of CT data points in these treatments exceeded the canopy temperature stress threshold of 28℃, with a dramatic reduction to 2% of data points exceeding 29℃. This phenomenon, combined with the increased uniformity in the relationship between CT and LWP following the inclusion of climatic data to the regression, suggests that during periods of no or limited water stress other environmental factors affect the regression, as the effect of canopy temperatures on leaf water potential is reduced. This research will provide a better understanding of the physiological and environmental processes that affect canopy temperatures and in turn water stress. Thus, enabling the judgement as to weather a measured canopy temperature represents water stress, for use in irrigation scheduling.

P 2.07 - Modifying nitrogen uptake and nitrogen utilization efficiency in rapeseed (Brassica napus L.) cultivars in response to water stress and nitrogen use Daneshmand A.1 (alireza.daneshmand@gmail.com), Noor-Mohamadi G.2 1 Islamic Azad University (Agronomy Department), Ghaemshahr Branch, Mazandaran State, Iran; 2 Islamic Azad University (Agronomy Department), Science and Research Branch, Tehran State, Iran. Environmental constraints are considerable in crop production in many regions of the word. Shortage of water is the most important factor limiting rapeseed production in many parts of the word, especially in arid and semiarid regions such as Iran. Rapeseed is a kind of oilseed plants that cultivation in Iran and has a relatively high demand for nitrogen because content of this nutrient in seeds and plant tissue is greater than in most grain crops. Nitrogen has a key role in this plant. Nitrogen concentration of plants varies with soil N status and soil moisture in wich water stress results in a decrease in N concentration and NUE that these caused to reduce net photosynthetic rate and mass production. Also, genetic variation in nutrient efficiency may be attributed to genotype differes in their effectiveness in absorbing nutrients from the soil (uptake efficiency) and differes in the efficiency with wich the absorbed nutrients are utilized for dry matter production(utilization efficiency). Experiments in rapeseed genotypes suggesting that genetic variation in nutrient uptake and efficiency is of greater important under suboptimal nutrient supply. Many experiments in rapeseed showed that total N-translocated amount and nitrogen utility efficiency decreases under water stress because early leaf senescence enhanced by water shortage can lead to a decrease in leaf N levels. In addition, transfer of N from leaves to the grain can be accelerated by limited N supply and limited N uptake from dry soil. In the present study, we determined the nitrogen uptake, nitrogen utilization efficiency, nitrogen uptake efficiency, photosynthetic rate, seed yield and yield components of two rapeseed cultivars (Zarfam and Moddena) subjected to three soil-moisture levels (irrigation after 40, 60 and 80 percent depletion of soil water) and four nitrogen rates (0, 75, 150 and 225 kg/ha). In our study nitrogen accumulation in all plant organs and nitrogen uptake in rapeseed cultivars, increased with increasing nitrogen and watering times. The present study demonstrate that severely deficient irrigation can decrease seed yield, N concentration in tissue plant and NUE through adversrely affecting N metabolism with early leaf senescence. In comparision of cultivars defined that Zarfam was N-efficient cultivar and may grow and function more effectively in nitrogen uptake and remobilization at lower levels of N and in water stress condition than do N-inefficient (Moddena) cultivar that this could lead to better seed yield in this cultivar. We concluded that water stress results in a decrease in leaf nitrogen content and this decrease photosynthesis and promoting senescene by decreasing nitrogen uptake efficiency.

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P 2.08 - Strategies and tactics of harvesting more water in semiarid agricultural systems Gan Y.T. 1, Bing D.J. 2（Dengjin.Bing@AGR.GC.CA）

1 Agriculture and Agri-Food Canada, Semiarid Prairie Agriculture Research Centre, S9H 3X2, Swift Current, Saskatchewan, Canada;

2 Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta, T4L 2J3, Canada. Water deficit is the most important climatic factor limiting the crop production and sustainability in semiarid environments. With the increasing trend of climate warming, the challenge of water conservation and utilization in agricultural systems becomes more critical than even before. In northern latitudes such as northern Great Plains of North America, northwest China, northern Europe, not only is less water available to crop production, compared to more humid regions, but also short growing season limits crop utilization of the available water. The key strategies for harvesting more water in semiarid areas rely on two equally important aspects: (i) promoting more efficient use of available water with improved crop management, and (ii) increasing the proportion of annual precipitation available for crop production with improving cropping systems. This paper reviews and summarizes some of the key strategies and tactics that Canadian producers on the semiarid prairie have been adopting in their production systems. This will include use of crop stubble to increase snow trap and reduce run-off in windy areas, use of crop residues for erosion control and water retention especially in slope lands, use of tall-stubble to improve microclimates for crop growth in semiarid climates; rotating shallow- and deep-rooting crops in well-planned crop sequences to increase water use efficiency; use of no-till to increase soil organic matter – a long-term approach to increase crop yield and water use efficiency.

P 2.09 - Water distribution profile under pulse and oilseed crops in the semiarid northern Great Plains of North America Gan Y.T.1, Bing D.J.2 (Dengjin.Bing@AGR.GC.CA)

1 Agriculture and Agri-Food Canada, Semiarid Prairie Agriculture Research Centre, S9H 3X2, Swift Current, Saskatchewan, Canada;

2 Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta, T4L 2J3, Canada. Oilseed and pulse crops have been increasingly used to replace conventional summer fallow and diversify cropping systems in the semiarid northern Great Plains of North America. The knowledge of water use (WU) and its distribution profile in the soil is essential for optimizing cropping systems aimed at improving water use efficiency (WUE). This study characterized water use and distribution profile for important pulse and oilseed crops compared to spring wheat (Triticum aestivum L.) in a semiarid environment. Three oilseed crops (Brassica napus canola, Brassica juncea mustard, Linum usitatissimum flax), three pulses crops (Cicer arietinum chickpea, Pisum sativum dry pea, Lens culinaris lentil), and spring wheat (control) were tested in removable 100 cm deep x 15 cm diameter lysimeters placed in an Aridic Haploboroll soil, in Saskatchewan, Canada, in 2006 and 2007. Crops were studied under low- (rainfall only) and high- (rainfall plus irrigation) water availability conditions where lysimeters were removed and sampled for plant biomass and WU at various soil depths. Wheat biomass yield was greater than pulse crop yields that were greater than oilseed yields. WUE averaged 4.08 kg/ha mm-1 for pulse crops, 3.64 kg/ha mm-1 for oilseeds, and ranged between 5.5 and 7.0 kg/ha mm-1 for wheat. Wheat used water faster than pulse and oilseed crops during vegetative growth period. Pulse crops took water mostly from the upper 60 cm soil depths, and left more water unused in the profile below 60 cm depth at maturity compared to oilseeds or wheat. Among the three pulses, lentil used the least amount of water, followed by chickpea and dry pea. Soil WU and distribution profile under canola and mustard were generally similar, with both using more water than flax. Differences in WU and distribution profile were similar for crops grown under low- and high-water conditions. A deep rooting crop grown after pulses may benefit more from water conservation in the soil profile than grown after oilseed or wheat. Alternating pulse crops with oilseeds or wheat in a well-planned crop sequence may improve WUE for the entire cropping systems in semiarid environments.

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P 2.10 - Comparison between surface and subsurface tape drip and furrow irrigation, systems on water use efficiency and yield of Safflower (Carthamus tinctorius L.) in Kermanshah province (west of Iran) Ghamarnia H. (hghamarnia@razi.ac.ir, hghamarnia@yahoo.co.uk), Sepehri S. Department of Irrigation and Water Resource Engineering, College of Agriculture, Razi University, Kermanshah, Iran. Under the semi-arid conditions of Iran, the water shortage is the major constraint factor of crop production. During the year, Rainfall is irregular and it is concentrated during autumn, winter and around one month of spring and without rainfall during summer months at all. Moreover, high temperature and evapotranspiration rates, in combination with limited water storage capacity of soils during winter, reduce water availability for crops during summer time. Moreover, using of different irrigation systems can help us to optimize the available water resource in the mentioned semi-arid area. So for this investigation and comparison of different irrigation systems such as: surface drip (tape), subsurface drip (tape) and furrow irrigation systems, on oil yield, yield component and water use efficiency of safflower (Carthamus Tinctorius L.) an experiment was conducted in the agricultural research station, water engineering department of Razi university of Kermanshah in the west of Iran in April 2008. For this study an experiment based on completely randomized block design with three replication was used. The different treatments were a combination or furrow surface irrigation 100%, surface drip irrigation 100% - subsurface drip irrigation 100%. The safflower seed variety was with Sina names. In this experiment for daily irrigation scheduling evapotran- spiration from pan class A were used. The result of experiment showed that the maximum of oil yield (1179 kg/ha) was belong to subsurface tape irrigation and the minimum of oil yield (960.2 kg/ha) belong to furrow irrigation. The statistically result showed that the effect of irrigation types on water use efficiency was significant and the maximum water use efficiency on oil production (P< 0.01) was 1.58 Kg/ha/mm for subsurface tape irrigation and the minimum water use efficiency on oil production (P< 0.01) was 0.69 kg/ha /mm and belong to furrow irrigation.

P 2.11 - Vegetation rehabilitation and soil water carrying capacity for vegetation in water-limited environment in semiarid region of Loess Plateau Guo Z.S. (zhongshenguo@sohu.com) Institute of Soil and Water Conservation, Northwestern A & F university, Chinese Academy of Sciences, Ministry of Water Resources, Yangling 712100, China. Because forest and vegetation is able to effectively conserve soil and water loss and to improve the environment, a large scale afforestation has been carried out in the Loess Plateau since 1950. Deep rooted, fast-growing plant and tree species was selected, planted and sown in the course of vegetation rehabilitation in order to pursue higher biomass, yield and ecological benefit. Plant roots grow quickly and take water without much restriction from considerable soil depth along with increasing age, but precipitation is the only source of soil water in the most part of semiarid or arid region on the Loess Plateau and the depth to which rain permeates the soil and soil water supply from precipitation is limited, resulting in the overuse of soil water resources and the maladjustment of soil water –plant growth relationship. Soil deterioration appeared on the Loess Plateau in the form of excessive soil drying under perennial grasses and forest land. In order to regulate maladjusted SWPGR, short for soil water-plant growth relationship, a foundation on which SWPGR regulation was made was first determined based on local soil water resources condition, which is SWCCV, short for soil water carrying capacity for vegetation. Taken the Caragana (Caragana korshinskii) forest as an example, a field experiment on the relationship between plant density, soil water and plant growth was conducted in the Shanghuang Eco-experimental Station in the semi-arid region of Loess Plateau, China. The precipitation inside and outside the forest, surface runoff, soil loss, soil water and plant growth and so on were measured under the same site and age condition. The result shows that with the increasing density, cover degree, canopies’ interception was increased, and surface runoff and its sediment charge reduces, and that there is a logarithm relationship between cover degree and runoff, an exponent relationship between plant

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density and canopy interception, the relationship between sediment charge and plant density can be expressed in“inverse-S shape” curve, and that the cover degree of the plant community and the benefits to conserve soil and water increases with increasing density. There is a maximum limit that is SWCCV. When the density surpass the limit, SWPGR should be regulated, otherwise, soil drying happen or strengthen.

P 2.12 - Improving productivity and sustainability in drought areas through resource conserving technologies: save water and reduce global warming Hossain M. I.1 (iliasrwrc@yahoo.com), Meisner C. A.2, Sayre K. D.3, Duxbury J. M.4, Gupta R. K.5 1 Regional Wheat Research Centre, BARI, Rajshahi, Bangladesh; 2 Cornell University, USA; 3 CIMMYT, Mexico; 4 Soil Science Department, Cornell University, USA; 5 CIMMYT India and Bangladesh. Rice-wheat (RW) cropping systems are critical to food security of increasing population in Bangladesh. However, the sustainability of RW systems is threatened by productivity decline and environmental sustainability. Crop production on permanent raised beds (PRB) with straw retention is expanding worldwide as a way to increase system productivity, diversify cropping and reduce global warming. When coupled with raised beds with straw retention can improve soil moisture retention, soil health, crop productivity and sustainability. A 3 years study was conducted at the Regional Wheat Research Centre, Rajshahi, Bangladesh as a warmer area, to compare the effects of five N fertilizer levels (0%, 50%,100%,150% and 200% N of recommended dose) and two straw retention (SR)/tillage treatments (100% SR of all crops+ Permanent raised beds (PRB), 0% SR +PRB, 100% SR+ Conventional tillage practice (CTP) and 0% SR+ CTP in a intensified RW systems by adding a third pre-rice crop of mungbean. Permanent beds with straw retention produced the highest productivity for all three crops in the sequence. Within each N rate the total system (rice-wheat-mungbean) productivity was greatest with 100% SR on PRB and least in CTP with zero straw retention. At 100% of recommended fertilizer N rate, mean annual system productivity was 12.5 t/ha for PRB with 100% SR, 11.2 t/ha with PRB without SR and 10.3 t/ha with CTP without straw. System productivity in N unfertilized plots increased when straw was retained due to increased supply and uptake of N. The results suggest that N fertilizer rates can be reduced when straw is retained. Soil organic matter in surface soil layers of the PRB had increased by 0.22% after 3 years (3 rice-wheat-mungbean crop cycles) with straw retention, with a greater increase with 100% SR. Straw retention is an important component of crop sustainability and may have long term positive impacts on soil fertility. Water use efficiencies improved 25%, 23% and 29% in wheat, rice, and mungbean crops, respectively when 100% SR with PRB system. By sowing crops on raised bed, irrigation water moves laterally from the furrow to the top and middle of the bed by capillary flow. Resource conserving technology required 103.8 litre/ha fuel per year compared to conventional method 135 litre/ha/year. 31.2 litre/ha/year fuel saved by resource conserving technology in rice-wheat-mungbean system. Compared with conventional tillage with all crop residues removed, the combination of PRB with residues retained appears to be a very promising technology for sustainable intensification of RW systems in Bangladesh.

P 2.13 - Evaluation of a water-saving superabsorbent polymer for forage oat (Avena sativa L.) production in an arid sandy soil Islam M. R. 1, 2 (irobiul02@hotmail.com), Eneji A. E.1, Hu Y.G.1, Li J.M.1

1 College of Agronomy and Biotechnology, China Agricultural University，Beijing 100193，China; 2 Department of Agronomy and Agricultural Extension, Rajshahi University, Rajshahi 6205, Bangladesh. Water is the main limiting factor for plant growth in large areas of the world, especially in arid lands. We studied the growth, biomass production, grain yield and water use efficiency (WUE) of Baiyan 7 (B7), a forage producing hulled oat, using different rates of superabsorbent polymer (0, 30, 60, 90 and 120 kg ha-1) in a wind erosion-prone arid sandy field in northern China. The oat was cultivated in two different seasons (early, with limited irrigation and late, under rain-fed conditions) in 2008. During the early season experiment (1st may to 31st July) total

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precipitation was 278.5 mm in 30 rainy days; sprinkler irrigation was applied (55.6 mm) once at 6 week after sowing. Total precipitation during the late season (11th July to 12th October) was only 156.2 mm in 22 rainy days. The above-ground biomass (AGB) increased significantly in both early (87.3%) and late (54.1%) season crops with the application of superabsorbent polymer at 60 kg h-1. The below-ground biomass (BGB), grain yield and number of panicles per unit area (PA), tiller fertility rate (TFR) as well as relative water content (RWC) and water use efficiency also increased significantly at the superabsorbent rate of 60 kg h-1. Water use efficiency was much higher (P<0.05) under late rain-fed conditions. The optimum application rate of superabsorbent polymer in the study area was 60 kg h-1; other rates were neither sufficient nor economical. The application of superabsorbent polymer could be an effective way of increasing water use efficiency and crop growth under arid conditions.

P 2.14 - Agronomic performance of high-yielding varieties in aerobic rice culture in Japan Katsura K.1 (kkatsura@kais.kyoto-u.ac.jp), Okami M.2, Mizunuma H.1, Kato Y.2 1 Experimental Farm, Graduate School of Agriculture, Kyoto University, Osaka 569-0096, Japan; 2 Field Production Science Center, The University of Tokyo, Tokyo 188-0002, Japan. The ‘efficient use of water’ is one of the most urgent issues for rice (Oryza sativa L.) cultivation in the world. Aerobic rice, intensive rice farming in aerobic soil, can greatly reduce the water input compared to that of flooded rice cultivation. The objective of this study was to compare the potential productivity of aerobic rice and flooded rice, using high-yielding varieties at two locations in Japan. The average yield under aerobic conditions was similar (in 2007, 7.9 t ha-1), or even higher (in 2008, 9.4 vs. 8.2 t ha-1) than that achieved with flooded conditions. Most of the rice plants grown under aerobic conditions showed longer growth durations, which compensated their poor early growths and enabled them to intercept more or comparable radiation, and higher radiation use efficiency relative to those grown under flooded conditions. The super-high-yielding variety ‘Takanari’ achieved over 10 t ha-1 with no yield penalty under aerobic conditions in 3 out of 4 environments. The favorable agronomic characteristic of ‘Takanari’ lay in the large sink size and the high biomass production. However, it showed unstable performance under aerobic conditions especially in early growth stage under dry soil conditions, which would be one of the bottlenecks for the stable high biomass productivity of aerobic rice. We conclude that a high-production system of rice in aerobic soil is promising in the temperate regions where spikelet sterility is not a problem. The high grain yield in aerobic soil was brought from enough radiation interception, high radiation use efficiency and large sink size.

P 2.15 - Agricultural production and challenges in the CWANA region Latiri K. ( kawther.latiri@gmail.com), CWANA IAASTD chapter 2 authors Laboratoire d’Agronomie, Institut National de la Recherche Agronomique de Tunisie, Tunisia. The CWANA (Central and West Asia, North Africa) region is the poorest region in the world in terms of water resources, globally and per inhabitant. Most countries are subject to drought and water scarcity is expected to intensify due to climate change. With a total area of 18.5 million km², the CWANA region occupies about 14% of the total area of the world. Its population is about 10% of the world population, while its water resources are only 2% of the world water resources. Agricultural production takes place in a difficult context and is subject to high drought risk. The region is semi to hyper-arid and rainfall is low and irregular. During the last 50 years and despite these constraints, agricultural production and yields increased, mainly in the irrigated systems. However, food production per capita did not increase and failed to keep pace with the rapid growth in demand. Food consumption increase was made possible by the high level of imports. Self-sufficiency ratios declined because of high birth rate in part of the region and increasing food prices. Also, agricultural production did not avoid environmental problems expressed in over-exploitation of water resources, soil degradation, pollution and loss of agro-biodiversity. As these trends are expected to continue in the coming year, food insecurity could increase and be aggravated by drought and climate change and result in intensifying pressure on natural resources with social and economic consequences. These trends are discussed and analysed. Options are presented to reverse them through less exploitative use of natural resources and the elaboration and adoption of policies and technologies

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which preserve natural resources, reduce poverty, improve social conditions and promote economic and human development.

P 2.16 - Agronomic effects on irrigated spring wheat under conservation agriculture using perma- nent raised bed in northwest China Ma Z.M. (mazhming@163.com), Zhang L.Q., Lian C.Y. Institute of Soil, Fertilizer and Water-saving Agriculture, Gansu Academy of Agricultural Sciences, Gansu 730070, China. Based on the water shortage and lower water use efficiency, the agronomic effects of irrigated spring wheat on permanent raised bed (PRB), fresh raised bed(FRB), zero tillage(ZT) and conventional tillage(CT) were studied from 2005 to 2007 by combining conservation tillage with furrow irrigation and control traffic. The results showed that the yield of spring wheat on permanent raised bed is reached 6354.04 kg/ha which increased by 7.91%, 6.27% and 1.28% compared to ZT, FRB and CT, respectively. As the decrease of irrigation capacity and water leakage, the WUE is reached 15.15 kg/mm which increased by 44.7%, 33.83% and 16.27% compared to CT, ZT and FRB, respectively. The yield of spring wheat on conservational agriculture using permanent raised bed is not increased remarkably but its WUE is increased remarkably over other options. PRB increased the weight of 1000-seeds, especially in 2 edge rows on bed. The weight of 1000-seeds increased 3.5-9.5%. The height is decreased and stem become thick. The stem diameter is increased 0.03-0.06 cm and stem thick increased 0.04-0.06 mm, the capacity of lodging resistance and root disease resistance is increased. In the beginning of wheat growth, the soil temperature of PRB is lower than FRB, but in middle growth the difference of soil temperature between PRB and FRB is reduced and it is higher for PRB than CT and ZT. It is advantageous to wheat growth and got higher yield. During the wheat growth period, the total irrigation is decreased by 18.47%, 66.75% and 92.45% than FRB, ZT and CT, respectively. Compared with CT and ZT, the soil water content in 0-120 cm for PRB is higher than other options. The soil water content in 0-20 cm is increased by 11.51% and 35.03% compared to ZT and CT, respectively. The water consumption from planting to first irrigation reached 53.24 mm, 59.36 mm, 67.52 mm and 105.68 mm for PRB,ZT, FRB and CT. It is decreased 11.49-98.49% for PRB compared to other options.

P 2.17 - Stress technology for saving nitrogen and irrigation water Mahmood-ul-Hassan M.A., Salem M.(mhj407jb@yahoo.com) Plant Breeding and Genetics Division, Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan Crop Science Institute, National Agricultural Research Centre (NARC, Islamabad). Three years field studies were carried out on medium loam alkaline soils to find out the effect of nitrogen and water stress interaction on rooting pattern and seed cotton (Gossypium hirsutum L.) yield of different cotton genotypes. Randomized complete block experimental design with split-split plot arrangements was employed in the field. All the genotypes were planted under four irrigation stresses i.e. irrigation at all growth stages (320 cm of total irrigation depth), irrigation stress at first fruiting stage (240 cm total irrigation depth), irrigation stress at second fruiting stage (240 cm total irrigation depth) and irrigation stress at both i.e. first and second fruiting stages (160 cm total irrigation water); and three nitrogen doses of 50, 100 and 150 kg ha-1 respectively. During 2005-06 three genotypes; NIAB-111, NIAB-999 and NIAB-98 were planted. Highest root-shoot ratio of 0.22 and 0.19 was found in NIAB-111 and NIAB-98 respectively in treatment where irrigation stress at second fruiting stage was given with 50 Kg N ha-1. Where as in NIAB-999 maximum root-shoot ratio (0.21) resulted at irrigation stress when given during first fruiting stage with 50 Kg N ha-1. NIAB-111 yielded highest seed cotton of 3756 Kg ha-1 with the application of only 50 kg N ha-1 and irrigating the crop at all growth stages so saving 66 % nitrogen. NIAB-98 showed highest level of drought tolerance during 1st fruiting phase, yielding 3437 Kg ha-1 seed cotton where as NIAB-999 gave better interaction by 2nd fruiting phase stress with 50 kg N ha-1 yielding 3357 Kg ha-1. These findings suggest that 33 % nitrogen and 12.5 % irrigation water can be saved in these genotypes while imposing irrigation stress at two different stages. Studies concluded that NIAB-999 and NIAB-98 can be successfully grown under limited irrigation resources and NIAB-111 produced better results with low nitrogen. During 2006-07 in

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NIAB-824, highest seed cotton yield of 3756 kg ha-1 was noted in control treatment. However seed cotton yield in medium stress and high stress treatment was noted 3636 and 3397 kg ha-1 respectively and it was statistically at par with the yield in control. These results revealed that 12.5% water can be saved without considerable yield loss as compared to control by imposing the moisture stress to the crop at second fruiting stage in the month of September. Up to 25% water and 33% nitrogen can be saved with a little yield loss by imposing stress at two fruiting phases (Phase 1st and phase 2nd) in the months of July and September). In NIAB-884 maximum seed cotton yield of 5193.17 kg ha-1 was achieved under no stress treatment with the application of 150 kg Nha-1. During 2007-08, NIAB-777 gave highest seed cotton yield of 4036 Kg ha-1 in control treatment (no stress) followed by 3797 Kg ha-1 seed cotton yield when irrigation stress was imposed at second fruiting stage however at these two stress treatments best interaction was observed with 150 Kg N ha-1 (in control treatment) and 50 Kg N h-1 (in 2nd stage stress). These findings advocate that by adopting this technology, in NIAB-777 we can save nitrogen up to 66 % and irrigation water up to 12.5 % with yield loss of only 239 Kg ha-1 as compared to recommended practices. Similar results were observed in standard variety CIM-496 resulting best seed cotton yield of 4587 Kg ha-1 at 2nd stage stress followed by 4364 Kg ha-1 seed cotton yield in control treatment. While considering interaction, best interaction remained in 1st fruiting stage stress with 50 Kg N ha-1 yielding 5294 Kg ha-1 followed by 4656 Kg ha-1 seed cotton yield with 150 Kg N ha-1. In case of NIAB-846 best interaction was found at 2nd stage stress and 1st stage stress with 150 Kg N ha-1 resulting 4267 and 4176 Kg ha-1 seed cotton yield respectively. On the basis of all these studies we conclude that we can save up to maximum 66 % nitrogen and 12 to 25 % irrigation water by application of stress technology to genotypes at different growth stages without considerable yield loss.

P 2.18 - The effect of complementary irrigations in different growth stages on yield, qualitative and quantitative indices of the two wheat cultivars in Mazandaran Malidareh A.G. (aghanbarym@yahoo.ca) Department of Agronomy, Agriculture College, Jouybar Branch, Islamic Azad University, Jouybar, Iran. In most wheat growing moderate regions and especially in the north of Iran, climate grain filling is affected by several physical and abiotic stresses. In this region, grain filling often occurs when temperatures are increasing and moisture supply is decreasing. The study was carried out in agricultural research farm, Jouybar Branch in 2007. The experiment was designed in RCBD with split plot arrangements with four replications. Four irrigation treat- ments included (I0) no irrigation (check), (I1) one irrigation (50 mm) at heading stage, (I2) two irrigation (100 mm) at heading and anthesis stage, and (I3) three irrigation (150 mm) at heading, anthesis and early grain filling growth stage, two wheat cultivars (Milan and Shanghai) were cultured in the experiment. Totally raining was 453 mm during the growth season. The result indicated that biological yield, grain yield and harvest index were significantly affected by irrigation levels. I3 treatment produced more tillers m2, productive tillers, harvest index and biological yield. Milan produced more tillers m2, productive tillers m2, while Shanghai produced heavier tillers and grain 1000 weight. Plant height was significant in wheat varieties while were not statistically significant in irrigation levels. Milan produced more grain yield, harvest index and biological yield. Grain yield shown that I1, I2, and I3 produced increasing of 5228 (21%), 5460 (27%) and 5670 (29%) kg/ha, respectively. There was an interaction of irrigation and variety on grain yields. In the absence of the irrigation reduced grain 1000 weight from 45 to 40 g. No irrigation reduced soil moisture extraction during the grain filling stage. Current assimilation as a source of carbon for grain filling depends on the light intercepting viable green surfaces of the plant after anthesis that due to natural senescence and the effect of various stresses. At the same time the demand by the growing grain is increasing. It is concluded from research work that wheat crop irrigated Milan cultivar could increase the yield in comparison with Shanghai cultivar. Although, the yield of Shanghai under irrigation was slightly lower than Milan this yield also was related to weather condition, sowing date, plant density and location conditions and management of fertilizers, because there was not significant difference in biological and straw yield. The best result was produced by I1 treatment. I2 and I3 irrigation were not significantly difference with I1 treatment. Grain yield of I1 indicated that wheat is under soil moisture deficiency. Therefore, I1 irrigation was better than I0.

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P 2.19 - Effect of drip fertigation on yield of white onion setts in water constraint situation Maragatham N. (maragathamm@yahoo.co.in), Teli K. Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore, India. A field experiment was carried out at Jain Agriculture Research and Development Farm, Jain Irrigation Systems Limited, Jalgaon, Maharashtra, India during October 2007 to January 2008 with an objective to evaluate drip fertigation at different level of fertilizer sources in white Onion setts. The white setts were tested because it saves the field duration of the crop and thus the total water requirement is minimized. The experiment was laid out in randomized block design with different fertigation levels. JV-12 variety of white onion was used as test variety. The results revealed that the highest polar and equatorial diameter, bulb shape index, number of scale leaves, double bulb production, bulb fresh and dry weight was observed in drip fertigation with 150% recommended dose of water soluble fertilizer. Lowest double bulb production was recorded in 100% recommended dose of fertilizer as of normal fertilizer. The highest onion bulb yield per hectare was recorded at drip fertigation through 150 percent recommended dose of fertilizer as water soluble and it was comparable to 125 and 100 percent RDF of water soluble. When different levels of RDF supplied through drip fertigation using normal fertilizers did not alter the onion bulb yield. Based on economics, the maximum B: C ratio of 2.93 was noticed in drip fertigation with 100% recommended dose of normal fertilizers which was closely followed by micro sprinkler irrigation with soil application of 100% recommended dose of fertilizer. Drip fertigation with 100% recommended dose of normal fertilizer and micro sprinkler irrigation with soil application of 100% RDF (150:125:200 kg NPK ha-1) would be an ideal practice to achieve greater yield, income and water saving benefits as compared to surface irrigation in white Onion production. This result encourages the production of white Onion in water limited scenario and also managing nutrient in labour constrain situation. So whenever water constrain situation occurs, Onion can be cultivated through drip fertigation or micro sprinkler irrigation.

P 2.20 - Tillage system effects on wheat water use efficiency, yield and yield components in semiarid Argentina. Mirassón H.1, Faraldo M.L.1, Brevedan R.E.2, Fioretti M.N.2

1 Facultad de Agronomía, Universidad Nacional de La Pampa. 6300 Santa Rosa, Argentina; 2 Departamento de Agronomía, Universidad Nacional del Sur and Centro de Recursos Renovables de la

Zona Semiárida (CONICET). 8000 Bahía Blanca, Argentina. In the semiarid environment of east-central La Pampa (36°46' S, 64°17' W) water is the major constraint to dryland wheat production. Wheat produced in that area is subjected to erratic and unpredictable periods of water stress. Conservation practices such as reduced (RT) or zero till (ZT) are often recommended as measures to control erosion and to increase water storage in the field. We have limited information in the semiarid temperate of La Pampa regarding the effects of crop management practices on water use, water use efficiency and crop production, so it is difficult to optimize a tillage management system to reduce cropping risks. An understanding of the relationships between tillage system and crop productivity under different levels of water availability are necessary when planning cropping strategies. The purpose of this work is to report the effects of three contrasting tillage practices: conventional (CT), reduced and zero till over three years (2005 - 2007, inclusive) on soil water storage, crop water use efficiency and wheat growth and yield on an Entic Haplustoll soil, with a sandy loam texture, in a semiarid environment. Wheat grain yields with ZT (1274 kg/ha) were higher than with CT (1072 kg/ha) and RT (718 kg/ha) in a very dry year (2005). Water use efficiency were 6.3, 5.8 and 4.0 for ZT, CT and RT, respectively. In a wet year (2007) yield of CT and RT were higher (3771 and 3800 kg/ha, respectively) than in ZT (2829 kg/ha). The difference was mainly due to a larger number of grains m-2. Water use efficiency of CT and RT were 10.9 and 12.0 kg mm-1 compared to 8.9 kg mm-1 in ZT. In an intermediate situation (2006) the response was an intermediate one, but with the lowest yield under ZT. Results indicate that ZT was a more productive wheat farming practice in very dry years, otherwise CT was a best choice.

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P 2.21 - Managing climate change and water stress: a 'MASSCOTTE approach' evaluation to canal irrigation Muza O. (oliviamuza@gmail.com) Pre-Doctorate Candidate and Freelance Consultant, #1633 Odzani Crescent, New Houghton Park Waterfalls, Harare, Zimbabwe, +263 91 2 614 945. Writing more than a decade ago, Tinker et al. (1990) noted that 'when climate change becomes apparent, there will be a period of increasing turbulence within agriculture'. Recent models further suggest that climate change will slow or reverse the poverty reducing impact of agriculture, with by one estimate, some 600 million people at risk of hunger if temperature increases by 3%. However, each crop and crop variety has specific climatic tolerance and conditions, it is not possible to model world agriculture in a way that captures the details of plant response in every location. Southern Africa for instance, is one of the regions that suffers most from climate change. Yet, rain-fed agricultural production in Sub-Saharan Africa is still volatile and only the interseasonal and interannual management of water offers a means of buffering regional production shortfalls. Zimbabwe an agricultural based economy has been hard hit by the persistent drought of the past 5 years, leading to low agricultural productivity, food insecurity, high food prices, unemployment and increased migration levels. Two critical challenges faced by farmers in a typical climatic change scenario are: (i) whether these new conditions will hold in the following year, because they have to make immediate decisions on cropping (ii) whether this change may last several years, because they then may have to adjust their farming system. The results of this study illustrate the implications of climatic change to crop stress and irrigation effectiveness in rural Zimbabwe (three Canal irrigation schemes: Bangure, Mushandike and Mutenderende). The paper is premised on the realisation that lack of conclusive local predictions affect farmers' flexibility and rapid response (change of cultivar, change of agronomic variable such as sowing date, change to a different crop or change to a completely different system, for example from arable to grassland). Irrigation is thus both an adaptation and mitigation strategy by small holder farmers. The MASSCOTTE approach to irrigation schemes evaluation (FAO, 2007) highlights the local level effectiveness of global technology developments in agriculture. Particularly, the evaluation diagnosies and evaluate obstacles, constraints and opportunities and develops a consistent modernisation strategy. The comprehensive MASSCOTTE approach provides community modern needs, issues and challenges, thus providing evidence based global bench marks for irrigation modernisation and oriented management at three levels: (i) canal operation (ii) mordenisation scope (iii specific identified targets in terms of effectiveness in relation to money, to water and with regard to the environment.

P 2.22 - The effect of drought stress on corn seed yield, its component and biological yield Nejad S.D.B. (Tayebsaki1350@yahoo.com) , Nejad T.S. Department of Agriculture Science and Research, Islamic Azad University, Ahvaz Branch, Iran. Regarding undeniable effect of dampness on corn yield, optimal irrigation treatment has an important role in improving farm and yield management. A research has been performed on Salemi Field located in Ahvaz province with mean rainfall of 256 mm a year. Experiment location has dry and semi-arid climate and with considering Ahvaz weather forecasting statistics of 40 years, annual mean rainfall 213/94 mm, annual mean temperature degree 25/24, the mean of maximum annual temperature degree 32/92, the mean of minimum annual temperature degree 18/4 centigrade. Experiment was done in search with factorial Experimental for CRBD is provided with 4 Replicate Factors contents : 4 levels different of irrigation (Optimal irrigation , Cut irrigation in 10 leaf phases & cut irrigation in flowering & filling seed period ) in secondary factor have three date sowing contents (20 July & 5 August & 20 August 2008) According to variance breakdown results, water stress, growth periods and their mutual

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effect on seed yield, harvest index and biologically yield was meaningful, but about the weight of thousand seed and the number of row in corn, just growth phase effect was not meaningful about these yield components. Drought stress resulted in biologic yield, seed yield, harvest index, the weight of thousand seed, and the number of raw in corn. Treatment mailed stress with acceptable seed function 12/8 ton in hectare could use less water of 1502 liter in one plot which regarding to shortage of water and drought phenomenon, this issue can be object of attention as well as it can be used.

P 2.23 - Management of water use efficiency in irrigated agriculture Odilavadze T.V. 1, Bziava K.G.1 (k_bziava@yahoo.co.uk), Katsarava T.1, Yegiazaryan G.2, Imanov F.3, Verdiyev R.3, Hoogenboom G.4 1 Department of Agricultural Land Reclamation, Faculty of Agroengineering, Georgian State Agrarian

University, David Aghmashenebeli Alley 13 km, Tbilisi 0131, Georgia; 2 Water Resources Use and Management Centre, Armenian State Agrarian University, 74 Terian Str.,

Yerevan-375009, Armenia; 3 Baku State University, 23 Academic Zahid Xalilov Street, Postal Code: AZ 1148, 1073/1 Baku,

Azerbaijan; 4 Department of Biological and Agricultural Engineering, College of Agricultural and Envi- ronmental

Sciences, The University of Georgia, Griffin, Georgia 30223-1797, USA. The effective use of water resources on the basis of introduction of modern technological schemes of irrigation and complex of agrotechnical actions is the basic strategic goal of the project entitled ‘Water Resources Management in Agroecosystems in the South Caucasus Transboundary regions (Armenia, Azerbaijan, Georgia’) which is carried out under the financial support of NATO Science for Peace program. For definition of an effective use of irrigation water and its influence on a final crop, comparison of three different irrigation technologies (gravity irrigation, drip irrigation and drip irrigation in combination with mulching) has been conducted. Optimum quantity of submitted irrigation water was defined according to the evapotranspiration which was determined using the ET gage and Blaney-Criddle and Penman-Monteith methods recommended by FAO Irrigation and Drainage Paper 56. Given experiment has revealed that in case of use of three different methods of irrigation technology, a parameter of efficiency of use of irrigation water will be changed according to which relation between an effective use of irrigation water for plants and final crop is defined easily. Thus the model offered by us ‘water-crop’ will be adapted.

P 2.24 - Run-off management and its uses in the dry areas of Egypt Omar S.A. (said_omar1959@yahoo.com), Moselhy N. M. M. , Hegazi A. M. Egypt has a total area of one million km2. Barren deserts represent more than 95% of the total country’s land area. Therefore, conserving of natural water resources and using it for human and animal drinking and may be for supplemental irrigation fore different crops under dry areas are the periorties and the main objective of the Desert Research Center (DRC) in Egypt. Rainfed agriculture in Egypt occupies 2-3% of agricultural areas, mainly in the North Western Coastal Zone (NWCZ), Sinai and in the South Eastern Corner (SEC). Although this may not appear significant in relation to the total irrigated areas, but it is important to local communities as well as, to the national security. The poorest households are living in these areas. Therefore, better management of natural resources especially the conservation of natural water resources and better sustain the livelihood of local communities are important objectives in Egypt.

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P 2.25 - The usefulness of the maximum daily trunk shrinkage to schedule deficit irrigation in almond trees Pérez-Pastor A.1,2 (alex.perez-pastor@upct.es), Pagán E.1, García M.1, Domingo R.1,2

1 Universidad Politécnica de Cartagena (UPCT). Dpto. Producción Vegetal. Paseo Alfonso XIII, 48.

30203. Cartagena, Murcia, Spain; 2 Unidad Asociada al CSIC de Horticultura Sostenible de Zonas Áridas (UPCT-CEBAS). Cartagena,

Murcia, Spain. The usefulness of the trunk maximum daily shrinkage (MDS) to schedule irrigation in 7 years-old almond trees (Prunus dulcis (Mill.) D.A. Webb cv. ‘Marta’) was evaluated during two seasons (2006 and 2007). Two drip irrigated treatments with a traditional method and another two with dendrometry-based method were compared: i) a control (CTL) irrigated at 120% of crop evapotranspiration (ETc) throughout the season, ii) a regulated deficit irrigation (RDIt) receiving 100% ETc, except during the kernel-filling stage (stage IV, June-August) when 30% ETc was supplied, iii) a dendrometry-based deficit irrigation continuous (DId), programmed to maintain the signal intensity (MCDDId/MCDCTL) around 1.1 throughout the season and iv) dendrometry-based regulated deficit irrigation (RDId) programmed to maintain the signal intensity (MCDRDId/MCDCTL) around 1.1, except during stage IV which was 1.4. The water applied in CTL treatment in the two years averaged 680 mm per year. Water saving respect to control averaged 21% and 50% in DId and RDIt, respectively, in RDId treatment these values were 57% and 32% in 2006 and 2007, respectively. The water stress integral (S) values calculated from the stem water potential at midday were similar in DId and CTL treatment, while both RDIt and RDId showed the highest values during the experiment. The increase in the irrigation scheduling frequency in 2007 (three times per week compare to one time per week in 2006), promoted that the signal intensity values were maintained closer to threshold values in dendrometry-based treatments with respect 2006 and leading to lower values of S　 in RDId treatment (64 MPa day compare to 88 MPa day in 2006). The vegetative growth decreased with the water stress obtaining a high negative correlation between S and trunk cross sectional area growth (TCSA) (TCSA=37.79 – 0.25S; r2=0.85**). Dendrometry- based treatments reduced kernel yield in 2007, but not in 2006. When kernel yield vs. TCSA ratio was considered no significant reduction was observed in these treatments compared with the control. Results show the possibility of scheduling irrigation with MDS signal intensity with two-three days intervals to maintain an adequate water status in the trees.

P 2.26 - Effect of drip fertigation on growth, yield and quality parameters of sweet sorghum Ponnuswamy K. (ponnuswamykaruppannan@yahoo.co.in), Arulraja S., Muthukrishnan P.

Department of Agronomy, Centre for Soil and Crop Management Studies, Tamil Nadu Agricultural University, Coimbatore, 641003, India. Sweet sorghum is currently being developed for the simultaneous production of grain and cane. Sweet sorghum has sweet juicy stem, which may be used for forage and silage or to produce syrup. In China, sugar is produced from sweet sorghum (Doggett, 1988). In Brazil, sweet sorghum is grown as a source for ethanol production. Its bagasse is more suitable for paper pulp and is used to manufacture Kraft paper, newsprint and fiber boards. Therefore, sweet sorghum is considered as a multipurpose industrial crop. It is also capable of producing high biomass, 70%-80% of which is the stalk. It can be grown to produce jaggery, syrup and most importantly the fuel alcohol. Sorghum also is very environmentally friendly in that it is water efficient, requires little fertilizer or pesticides and is biodegradable. This is a huge benefit for the more environmentally sensitive areas of the world. This ‘camel among crops’ could be the key to agricultural development in areas affected by aridity and saline soils. Ravi et al. (1997) reported that 2760 lit.ha-1 of ethanol can be obtained from sweet sorghum. Cultivation of approximately 250 ha. of sweet sorghum would result in 500 KW power production. Sweet sorghum can be harvested around 100-120 days even with limited irrigation. Sweet sorghum has a potential ethanol yield of 4000 l·ha-1 where as corn, wheat and grain sorghum produce only 2290, 917 and 813 l·ha-1 of ethanol. Sweet sorghum is also called as sugarcane of temperate zone and its production capacity is equal or

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superior to sugarcane in the tropics when considered on a monthly basis. Unlike sugarcane, sweet sorghum has a wide range of growing conditions and requires low unit costs due to less consumption of water and fertilizer. Since sweet sorghum is a short duration (4 months) crop with less water requirement crop compared to sugarcane with higher sugar related quality characters, there is a scope for the introduction of sweet sorghum in Tamil Nadu. The treatments failed to exert marked variation on brix, sucrose, reducing sugar of sweet sorghum juice. Drip fertigation with 150 percent recommended dose of NPK (WSF) recorded higher grain yield (3.21 t·ha-1), highest girth of millable cane (6.9 cm) and highest millable cane yield (103.4 t·ha-1). Even though drip fertigation with 150 percent recommended dose of normal fertilizers has recorded the maximum cane yield, it is on par with 125 percent recommended dose of normal fertilizer. There is no significant influence on quality characters (sucrose and reducing sugar) of sweet sorghum by the treatments. Hence it is concluded that drip fertigation with 125 percent recommended dose of fertilizer with normal fertilizer could be recommended for maximizing sweet sorghum cane yield.

P 2.27 - Drip fertigation with water soluble fertilizers to enhance the productivity of maize Ponnuswamy K. (ponnuswamykaruppannan@yahoo.co.in), Muthukrishnan P.

Department of Agronomy, Centre for Soil and Crop Management Studies, Tamil Nadu Agricultural University, Coimbatore, 641003, India. Maize or Indian corn (Zea mays L.) is one of the most important cereal crops in the global agricultural economy both as a food for man and feed for animal. It is a miracle crop, has very high yield potential, there is no cereal crop on the earth that has so immense potential and so called ‘Queen of cereals’. In India, it occupies third place among the cereals after rice and wheat grown in an area of 7.59 million hectares with a production of 14.71 million tones and the average productivity is 1936 kg/ha. The area under maize is expected to increase in future due to ever increasing water shortage and the demand of maize grain in poultry and animal feed industries. Efficient utilization of available water resources is crucial for a country like India which shares 17 percent of the global population with only 2.4 percent of land area and 4 percent of the water resources (Suryawanshi, 1995). The area under maize is expected to increase in future due to ever increasing demand of maize grains in poultry and animal feed industries in Tamil Nadu. At present, there exists a gap of about 10 lakh tonnes of maize grain between production and demand. When fertilizer is applied through drip, it is observed that beside the yield increase about 30 percent of the fertilizer could be saved (Sivanappan and Ranghaswami, 2005). One of the possible way to bridge the gap between demand and supply is to increase the productivity per unit area by adopting the appropriate production and management technologies, besides increasing the area under maize cultivation. Keeping this in view, an experiment was conducted at Coimbatore to study the feasibility of introducing drip irrigation and fertigation in maize. The results revealed that irrigation at 100 percent PE recorded higher grain yield (7005 kg/ha) which was significantly higher than other irrigation regimes. Among the fertilizer levels, 100 percent RDF through drip recorded significantly higher grain yield of 6899 kg/ha and was on par with 75 percent RDF through drip.

P 2.28 - The effects of planting density on the trend of grain filling: yield and yield component of three chick pea (cicer arietinum L.) varieties in Kermanshah Shamsi K. (shams2_k@yahoo.com) Islamic Azad university, Kermanshah Branch, Iran. A field experiment was conducted to evaluate effects of planting density and variety on the trend of grain filling, yield and yield component to chick pea. The present research was conducted at experimental farm of mahydasht (Kermanshah). The factorial experiment was designed based on complaete randomized block desigen with four replication. In this experiment, the variety in three level (Jam; ILC-482 and 12-60-31) and the planting density in three level (19, 28 and 57 plant·m-2) were considered. The trend of grain filling, yield component and agronomic characteristics: as some biomass yield, harvest index, number of pods per plant. Number of grain per plant, number of node per main stem, plant height, number of branch per plant; weight of 100 grain; distance between 1st pod to soil, distance between 1st branch to soil and phonological stages the chick pea varieties based on photo growing

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degree day (PHOTO GDD) Were calculated. The result achieved showed that the maximum speed of grain filling related to density of 28 plant.m-2 and ILC-482 variety. Grain yield; number of pods per plant; number of grain per plant; weight of 100 grain; plant height; distance between 1st pod to soil and distance between 1st branch to soil were significantly affected by variety and density but number of branch per plant was affected by density and number of node per main stem and harvest index were affected by variety. The maximum photo growing degree day Related to 12-60-31 variety and the maximum grain yield related to density of 28 Plant·m-2.

P 2.29 - Water use efficiency, yield and soil edaphic environment under tillage and land shaping techniques in rainfed agroecosystem in India Tarafdar P.K. (pktarafdar@rediffmail.com), Masanto S. Department of Soil and Water Conservation, Faculty of Agriculture, Bidhan Chandra Krishi Viswa Vidyalaya, Mohanpur (742132), Nadia,West Bengal, India. Poor soil profile moisture and its variability over the years alongwith other biophysical constraints are the principal stress factor leading to low and unstable crop yields in Kansabati watershed occupying under rainfed agroeco system in West Bengal, India. Efficient soil management practices are necessary for conserving soil moisture towards its utilisation in dry season, improving soil edaphic environment and stabilisation of crop yields in this agroecosystem. The present investigation was undertaken in patloinala microwatershed under Kansabati command area involving the treatments of i) two tillages-Shallow and Deep ii) three methods of land shaping – wide ridge and narrow furrow, same ridge and furrow and narrow ridge and wide furrow and iii) three levels of fertilisers taking groundnut as test crop.Maximum growth, yield and oil content were observed under deep tillage and wide ridge and narrow furrow planting methods associated with highest water use efficiencies by the crop. The soil edaphic environment like bulk density, porosity, fertility in soil also found to be improved with the same treatment. Higher water use efficiencies under deep tillage and wide ridge–narrow furrow planting methods facilitated better root growth and density favouring soil aggregation that lead to yield benefit of crop.

P 2.30 - Relative importance of surface runoff on planted forest ecosystem under the different climate regions in the Loess Plateau Wang M.C.1, Wang J.X.2 (wang118@126.com) 1 College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China; 2 College of Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China. Foresters have planted trees in arid zones for nearly a century, but unfortunately results have usually been disappointing. The same situation happened and continues happen in Loess Plateau. It is estimated that only 25 percent survival of 10 million hectare of the planted trees in the Loess Plateau in the past five decades. As far as the trees survived are concerned, most of them are low-growing, poorly formed and continuously deterioration of the soil water condition. Based on principles of water balance and water transport theory of SPAC, the amount of water consumption at Black Locust plantation ecosystem in the semiarid and subhumid regions of Loess Plateau were measured and calculated, the controllable water transport pathways and relative importance of plantation ecosystems were discussed. The result shows that, whether rainy year or dry year, semiarid or subhumid region, the site evaporation account for a large proportion in the total water consumption, transpiration next, crown interception and surface runoff smallest, but the importance of manual regulation is: evaporation>runoff> transpiration>crown interception. By the analysis of soil water retentive ability and precipitation characteristics, the conclusion was drawn that the measures of inhibiting evaporation is more effective than that of harvesting runoff in semiarid-forest steppe belt-light loam soil zone, by contrast, the measures of harvesting runoff is more effective than that of inhibiting evaporation in subhumid-deciduous broad-leaved forest belt-middling loam soil zone of Loess Plateau.

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P 2.31 - The preliminary study on cultivation and use of upland rice in Bulang nationality of China Yang Y.Y., Xu F.R., Zhang D.Y., Dong C., Dai L.Y. (Luyuandai@yahoo.com.cn) Key Laboratory of Biotechnology, Yunnan Academy of Agriculture Science, Kunming, Yunnan 650223, China. Bulang nationality was unique and ethnic minorities in Yunnan province of China, and also was one of the oldest indigenous peoples. Bulang lived in nine cities and counties includeding Xishuangbanna prefecture, Baoshan City, Lincang City etc.. We chosed 4 counties and 8 countries (4 rural Bulang and 4 distribution of a higher concentration of Bulang in four prefecture or cities, a total of 20 villages surveyed. This study focus on the relationship between local climate and the main rice resources in these areas. The results were :1. The total land area of eight townships in Bulang four county were 2302.77 squ kilometers, a total arable land area were 152.40 square kilometers, and the total rice area were 32.60 square kilometers, the area of arable land accounts for about 1/5. 2. An elevation of Shidian County of Baoshan City, Menghai county of Xishuangbana prefecture, Shuangjiang County of Lincang City, the town of purple rice-Mojiang County of Puer City which have been investigated were ranged from 1043 m to 2389 m, but one common character of their climate conditions was the warm climate in all year round, but obvious dry and rainy season, seven-months dry season ,the frequent occurrence of drought. 3. In these areas, we collected the main varieties o rice are mainly local varieties, a total of 83 assections which there are 34 rice, 49 upland rices (the proportion was 59%); of which 62 assections were from Menghai country, 46 upland rices were collected in the area of rice (accounted for 74%), and most of them were glutinous and purple rice. Glutinous rice and its products were necessities for Bulang customs of the daily life and religious festival. In conclusion, the reason why Bulang people cultivated the upland rice in warm and humid climate in area of residence options, is that the pressure of 6-7 months of dry season, upland rice varieties as drought-resistant varieties were the choice of Bulang people to fully use up, and formed a unique characteristics of Bulang local rice germplasm resources. That was a solid foundation for the study on the relationship between the traditional practices of Bulang indigenous knowledge and the function of the formation of the genetic diversity of rice germplasm resources.

P 2.32 - Comprehensive agricultural development with rainwater harvesting promotes poverty alleviation in arid areas of Gansu Zhu K. (lzkz_ws@yahoo.ca) School of Environmental & Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, Gansu 730070, China. Arid and semi-arid Loess Plateau of Gansu with the unfavorable natural conditions is categorized as the remote and disadvanced region in China, where water scarcity is the key t barrier to restrain sustainable development, Since early 1990’s, the Provincial Government of Gansu has carried out ‘121 Project’ for rainwater harvesting in which each farmer family is encouraged to build up 2 rainwater storage cisterns and develop a piece of yard land to be irrigated by rainwater. Up to date, almost a total volume 216 million m3 of cisterns has been built in Gansu, which made 352.000 ha agricultural land irrigated. Such family based water cisterns have proved that rainwater harvesting could provide enough fresh water supplies for a family’s annual normal consumption including drinking, animal feeding and necessary backyard irrigation. For the study on poverty alleviation, a successful sample by using rainwater harvesting was investigated in Dingxi City of Gansu that was well known to China in past due to its harsh natural conditions and extreme poverty. Since 1994, Dingxi has built 320,000 cisterns in which the stored rainwater can serve 1.5 million people and 800,000 cattle pluses land irrigation. Thus, UNEP sets up a demonstration station of rainwater harvesting and utilization in Dingxi for training technicians from different countries. Furthermore, ‘121 Project’ has another duty to train farmers how to use the harvested rainwater technically and sufficiently for water-saving agriculture. Farmers are trained to create the comprehensive economic agricultures, i.e., cash-crops were highly emphasized instead of the

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traditional agricultural products. On basis of local natural conditions, potato that is considered as the most competitive agricultural product, is accentuated to be widely planted at 240,000 ha land with the total annual production of 5 million tons. One third of annual income for farmer families comes from potato planting. Farmers actively built greenhouses everywhere in which the valuable products, such as herb-medicines, mushrooms, floras, strawberries and unseasonable vegetables, are growing for 4 seasons, bring the tremendous income to the former poor families. Plantation of flora and medicinal herbs has technically been guided by agricultural institutes. With swift economic development promoted by the comprehensive economic structure, Dingxi region has become the largest flora base in the Northwest District of China, and one fifth of farmer’s income comes from flora in addition to another main income from medicinal crops. According to an investigation, a technically managed greenhouse could, in average, make US$2,800 per year. A new investigation has indicated that the farmer family income capita from US$48.5 in 1990 sharply increased to US$386 in 2008 when the strategy of comprehensive agricultural development evidently promoted the poverty alleviation in this arid and cold region.

P 3.01- Response of nonnodulating, nodulating and supernodulating soybean (Glycine max L.) genotypes to potassium fertilizer under drought stress Abdelhamid M.T.1 (magdi.abdelhamid@yahoo.com), Kamel H.A. 2, Dawood M.G. 1 1 Botany Department, National Research Center, Dokki 12622, Cairo, Egypt; 2 Radioisotopes Department, Atomic Energy Authority, Dokki 12311, Cairo, Egypt. Soil moisture is a principal environmental factor limiting legume productivity in the tropics and sub-tropics. Soybean is a major crop for oil and protein consumption by human, animal and fuel. A pot experiment at the wire house of National Research Centre, Cairo, Egypt was conducted using three Japanese soybean (Glycine max L.) genotypes, nonnodulating (NN) (En 1282), nodulating (N) (Eneri) and supernodulating (SN) (En-b0-1) were grown under two potassium fertilizer levels (25 and 150 mg/kg soil as K1 and K2, respectively). Sixty five days after sowing (pod filling stage), soil moisture (SM) of plants was maintained at 65% FWC for control (WW) and no water was added considered as water stressed plants (WS). The drought stress was conducted for 8 days. Water stress (WS) reduced the dry weight of both shoots and roots as well as the total plant dry weight of the three soybean genotypes compared with well-watered (WW). K2 significantly increased total dry weight and total N compared with K1 in the three genotypes. Nodules numbers and weights were significantly decreased by water stress. N2 fixation was the most sensitive parameter to water deficits, so it was completely inhibited. K2 level significantly increased nitrogenase activity in both genotypes (N and SN) by 2.7 and 1.4 folds, respectively. Water stress significantly decreased relative water content of the three genotypes. K2 resulted in significant increase in RWC of NN and insignificant increase of N and SN genotypes. Water stress and /or K treatments caused significant increase in both of free amino acids and proline in the three soybean genotypes. Water stress reduced shoot dry weight, pods number per plant, seed number per plant and seed yield in all soybean genotypes used. K2 at high level (K2) under well-watered soil condition significantly resulted in highest values of seed yield in N and SN genotypes. The oil, total carbohydrate, phosphorous and potassium contents were significantly reduced while total crude protein was significantly increased due to water stress in all genotypes used. In conclusion, water stress adversely affected most of the studied traits. The application of potassium mitigated the adverse effect of water stress, which facilitated the conditions that favored more or higher growth and yield levels of soybean crop.

P 3.02 - Effect of drought stress on some morphological and yield of three genotypes of sugar beet Adibifard N.1 (navid_af@yahoo.com), Mottaghi S.2 , Lotfifar O.3 1 Islamic Azad University of Vramin, Iran; 2 University of Tehran, Abooreyhan campus, Iran; 3 University of Tehran, Abooreyhan campus, Iran. This research was executed in Shahid Motahari research farm at sugar beet research institute on Kamalabad of Karaj in 2005. In this research is studying the reflection of drought stress on the quality and quantity yield and any morphological indexes on 3 sugar beet genotypes (BP Mashhad, BP Karaj and 191) which are multigerme. The

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experimental design was the randomize complete block that was studied on drought stress condition in 3 interval irrigations: non stress (irrigate after 80 mm evaporation from A class pan), middle stress (irrigate after 130 mm evaporation from A class pan) and severe stress (irrigate after 180 mm evaporation from A class pan).The amount of water in every irrigation was calculated by WSC flume. The used irrigation water in each treatment was 13579 m3/ha for non stress treatment, 11379 m3/ha for middle stress treatment and 7859 m3/ha for severe stress treatment. Field production and gathering the samples was done in 3th November 2005. In effect of drought stress the number of xylem and phloem in sugar beet petiole was reduced. The percent reduction of total root (root & crown) dry weight in the middle stress and severe stress condition in comparison with non stress condition were 45% and 51% and BP Karaj genotype on the total root dry weight in comparison with the non stress condition has the least reduction. The weight reduction of the shoot which is affected by the middle and severe stress in BP Mashhad genotype has the most reduction and BP Karaj genotype has the least reduction on the comparison with the non stress condition. The sugar yield and white sugar yield that was affected to the water stress treatment and was reduced by increasing the amount of stress and the most reduction was seen in white sugar yield in BP Mashhad genotype in middle and severe stress condition in comparison with non stress condition and the least reduction was seen in 191 genotype. The most water irrigation use efficiency in non stress condition had gained 0.037163 kilogram sugar per using some meter cube water and this parameter was reduced affected by drought stress and BP Mashhad and 191 genotypes had the least water irrigation use efficiency. The average of root yield in different treatment was 37.97 t/ha (non stress), 17.78 t/ha (middle stress) and 15.466 t/ha (severe stress) and the 191 genotype root yield was decreased more than two other genotypes at severe stress condition (with 14 percent reduction). Finally drought stress caused the reduction of measuring parameter and increased sugar content and finally two BP Mashhad and BP Karaj genotypes were accepted for using in breeding programs to residential drought.

P 3.03 - Promotive effects of 5-aminolevulinic acid on growth, yield and gas exchange capacity of barley (Hordium vulgar) grown under drought condition. Al-Khateeb S.A. (skhateeb2@yahoo.com) Crops & Range Department. College of Agric & Food Sci, P.O.Box 420, Al-Hassa, 31982. King Faisal University, Suadi Arabia. 5-aminolevulinic acid (ALA) is precursor of tetrapyrrole compounds such as chlorophyll, phycobilin, heme and vitamin B12. ALA promoted the growth and yield of several crops at low concentration. In the present study the effects of ALA on growth, yield and gas exchange capacity of barley (Hordium vulgar) grown under drought condition were evaluated. Barley was irrigated every 7, 14, 21 days and ALA was applied by foliar spray at concentration of 25,50,100 ppm as well as control. Results showed that irrigation intervals of 21 days significantly reduced grain and straw yield and this reduction was attributed to reduction in plant height, spike length, no. of grain/spike and weight of grain/spike. ALA spray significantly increased grain yield particularly under concentration of 50 and 100 ppm. This increased was accompanying with increase in plant height, spike length, no. of grain/spike and weight of grain/spike. The height grain yield was noticed under 7 days intervals and spraying with concentrations of 50 and 100 ppm. Net photosynthesis (NP), stomatal conductance (gs), transpiration rate (T) were significantly reduced with increasing irrigation intervals while the opposite was noticed in chlorophyll content. Mesophyll conductance (gm) was significantly higher under 14 days irrigation intervals. Intercellular CO2 concentration (Ci) was not affected by irrigation intervals. ALA did not significantly affected NP, gs, T, Ci and chlorophyll content while gm was significantly increased under 100 ppm ALA. The highest NP and gs were appeared under 7 days irrigation intervals and 25 and 100 ppm ALA spraying. Promotive effects of ALA was appeared under normal condition of irrigation particularly under 7 days irrigation intervals.

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P 3.04 - Response of common bean (Phaseolus vulgaris L.) cultivars to terminal drought in the southern west of Iran Barary M.1 (bararym@gmail.com), Baghlani H1., Fasihi K.1, Nasrollahnezhad A.A.1, Poursiabidi M.2 1Ilam University, Ilam, Iran; 2Agricultural Research Centre of Ilam, Ilam, Iran. A field experiment was conducted to examine the response of common bean (Phaseolus vulgaris L.) to terminal drought in the southern west of Iran in spring 2008. Three cultivars of common bean including pinto (cv. Khomain), red (cv. Derakhshaan) and white (cv. Dehghaan) were grown under field conditions by pod filling stage when two water treatments i.e. control and water withholding were applied. A randomized complete block design with split plot arrangement was used with 3 replications so that water treatments were assigned in main plots and cultivars were as sub-plots. The results showed that there were significant differences among cultivars for various plant traits such as grain and leaf protein content, leaf chlorophyll content, leaf relative water content, yield and yield components and harvest index, indicating the existence of genetic variation among genotypes. Grain yield, number of seed per pod, number of pod per plant, total biomass reduces significantly under water deficit condition compared to non-stress conditions. Under non-stress condition, yield was highly correlated (r2 = 0.92) with the total biomass and under water stress condition it was highly correlated (r2 = 0.98) with pod dry weight. The results of stepwise regression showed that under non-stress conditions, 100-grain weight explained 96 percent and for stress condition leaf dry weight explained 84 percent of total variation in grain yield. The results of multiple regression showed that under stress condition the total biomass and harvest index explained 98 percent of total variation in grain yield. Path analysis showed that the highest direct effect, being positive, was related to total biomass (r2 = 0.94) in non- stress treatment and was related to pod dry weight (r2 = 0.420) under stress condition.

P 3.05 - Drought effect on germination and seedling emergence inhibition in durum wheat (Triticum durum Desf.) monitored by chlorophyll fluorescence Bchini H.1 (houcine.bchini@gmail.com), Sayar R.2, NACEUR M.N.3

1 Physiology Lab., National Institute of Agriculture research of Tunisia (INRAT), Elafareg Research

Station (Beja), Tunisia; 2 National Agriculture Research Institute of Tunisia (INRAT), Kef Research Station 7119 Boulifa, Le

Kef, Tunisia; 3 INRAT, Physiology Lab., Rue Hedi Karray 2049, Ariana, Tunisia. The present investigation has been performed to evaluate durum wheat (Tritium durum Desf.) tolerance to water stress at the water potentials of -2, -4, -6 and -8 bars induced by polyethylene glycol PEG- 8000 (polyethylene glycol 8000) solution at an early stage of plant growth. Each, on germination, emergence and early seedling growth, were investigated for two durum wheat (Tritium durum Desf.) varieties differing in drought tolerance (BD290273 and Omrabia). Daily and final germination and emergence percentage, as well as germination, root length and seedling emergence rate, Chlorophyll Fluorescence and seedling fresh and dry weight were measured in this study under controlled conditions. Results showed those germination and emergence rates were delayed by PEG solutions in both varieties, with differences between genotypes among growth stages, given that Omrabia variety showed a higher germination, root length, chl. Fluorescence ratio (Fv/Fm) and emergence rate than BD290273 genotype. This conclusively proves that the adverse effect of PEG on germination, emergence and early seedling growth was due to the osmotic effect rather than the specific ion. This difference of cultivar’s behaviour according the growth conditions is discussed. It was concluded that inhibition in germination at equivalent water potentials of PEG was mainly due to an osmotic effect. Therefore, this study showed that appreciation of drought tolerance in early seedling growth it is possible by using both tests (chl. fluorescence extinction and germination). Chlorophyll fluorescence extinction measurement seems to be a reliable test enabling the classification of varieties according to their drought tolerance.

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P 3.06 - Performance of contrasted rice genotypes grown under water saving irrigation and trait discovery for genotype improvement Bueno C.S. 1, Lafarge T. 1,2 (tanguy.lafarge@cirad.fr), Bucourt M.1 1 Crop and Environmental Sciences Division, International Rice Research Institute, DAPO Box 7777,

Metro Manila, Philippines; 2 Centre International de Recherche en Agronomie pour le Développement, UPR Adaptation Agroé-

cologique et Innovation Variétale, Montpellier, F-34398, France. Water saving technologies without reduction on grain yield, like alternate wetting and drying (AWD), have been implemented successfully in irrigated rice fields. It is now needed to identify key crop traits under more pronounced water constraint for genetic improvement and further increase in water productivity. Five contrasted genotypes were grown under three water treatments in 2006 (AWD30 with irrigation set up whenever soil water potential reached -30 kPa at 15 cm deep, AWD60, and CF as continuous flooding) while nine genotypes were grown under two water treatments in 2008 (AWD30 and CF). While water use decreased significantly for all genotypes by 29% to 37% under AWD30 and by 22% to 34% under AWD60 in 2006DS, and by 17% to 25% in 2008DS, grain yield was maintained only in rare cases which expressed high contrast among genotypes’ responses: grain yield of PSBRc80 was maintained in all situations while that of IR64 was significantly and systematically affected. The response of yield components to AWD was, however, not consistent with regard to the performance: cases with stable grain yield included some with unaffected yield components (three genotypes) and others with compensation between panicle number and filled grain number per panicle (PSBRc80). Cases with reduced grain yield included some with reduced grain size (two genotypes including IR64) and others with reduced filled grain number per panicle (two genotypes). Tiller emergence rate and maximum tillering increased under AWD for all genotypes, however, effect on LAI and biomass accumulation was inconsistent. Partitioning to culm was favored under AWD to the detriment of blade during the reproductive phase of the most adapted genotypes in 2008 although this was not reported in 2006. Under CF, the root/shoot ratio, total root dry matter and root dry matter below 25 cm deep were consistently higher, but for the most three adapted genotypes only. As a response to AWD, the root/shoot ratio and total root dry matter of these genotypes were maintained (in 2006) or even increased (in 2008) while those of a genotype bred for aerobic conditions were rather low under CF, but its partitioning to root dry matter at deep layers increased strongly under AWD. Although the plant type and traits responsible to AWD adaptation were not clearly consistent among the promising genotypes under study, the size, distribution and adaptation of the rooting system were clearly identified as key crop traits for adaptation to alternate wetting and drying.

P 3.07 - Water deficit stress on some physiological and agronomical characteristics of sunflower new hybrids Daneshian J.1 (j_daneshian@yahoo.com), Jonoubi P.2

1 Seed and Plant Improvement Institute, Karaj, Iran; 2 Tarbiat Moalem University, Tehran, Iran. Water deficit stress effect was studied on new sunflower hybrids. Two experiments were conducted as base of complete Randomized block design in 2005. Eleven Hybrids as name as SHF 81/82, SHF 81/85, SHF 81/33, SHF 81/75, SHF 81/60, SHF 81/90, SHF 81/115, SHF 81/108, SHF 81/84, SHF 81/36, SHF 81/95 and CMS 26* R-103 produced by Iranian CMS and Restorers lines and four commercial hybrids as, Azargol, Allstar, Mehr, Hysun33 were compared in two water conditions. In the first experiment, all plots were irrigated after 60 mm evaporation from pan, class A. In the second experiment, plots irrigated after 180 mm evaporation from pan. There were significant differences in morphological and physiological traits, yield and its relative characteristics to water deficit. However, hybrids reactions were different to water conditions. Some hybrids improved root extension, therefore they adsorbed much water in the soil in water deficit condition. They had the lowest head reduction among others. There were positive and significant correlations between stem diameter and water deficit tolerance. Water deficit caused to reduce leaf numbers and areas in plants, but the most reduction occurred in sensitive

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hybrids. They produced the lowest yield. The tolerant hybrids controlled stomata conductance and had more Relative Water Content in leaves than sensitive hybrids. Productivity effort that indicated remobilization of assimilate to development organs were different in hybrids to water deficit. It was reduced by water deficit, but the percentage of reduction was low in some hybrids. Water deficit sensitive and tolerant indices as MP, GMP, STI, SSI and TOl were studied. The yield in good water and water deficit conditions had positive and significant correlations with MP, GMP and STI indices. Azargol and Hysun33 Were the best hybrids because they produced the highest seed in two water condition. They were late maturity hybrids and there were positive correlation between growth duration and water deficit tolerant, because of good root growth, SHF 81/85 and SHF 81/108 had the lowest reduction in stomata conductance, RWC, leaf number and stem diameter. Therefore, the had the lowest seed reduction among new hybrids.

P 3.08 - Drought tolerance evaluation of new potato varieties with large root system in the comparison of commercial variety Deguchi T., Tago A., Wangchuk P., Iwama K. (iwama@res.agr.hokudai.ac.jp), Jitsuyama Y., Naya T., Miura Y. Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan. Potato plants are very sensitive to drought, mainly due to their shallow root system. We bred new potato (Solanum tuberosum L.) cultivers ‘Konyu’ with high productivity and large root mass in 2007. To evaluate their drought tolerance, a field experiment under irrigated and progressively droughted soil conditions was carried out. Root length density, photosynthetic rate, stomatal conductance and leaf water potential were compared between ‘Konyu’ varieties and widely cultivated commercial variety, Konafubuki, with high tuber starch yield and small root mass. Total root length and leaf water potential of ‘Konyu’ varieties were significantly higher than those of Konafubuki regardless of water treatment. In droughted plot, leaf water potential showed significant positive correlations with stomatal conductance and photosyn- thetic rate. Although all varieties showed significant yield reduction in progressively droughted plot relative to irrigated plot, ‘Konyu’ varieties showed smaller reduction than Konafubuki. We concluded that large root mass of Konyu varieties could maintain better water status and contributed to less reduction of photosynthetic rate and tuber yield even in progressively droughted condition.

P 3.09 - Determining relationships among yield and some yield components using path coefficient analysis in chickpea (Cicer arietinum L.) Fayyaz F. (Fayyaz.Farzad@Gmail.com), Talebi R. Department of Field Crops Improvement, Faculty of Agriculture, Azad University, Sanandaj, Iran. This research was conducted to determine the relationships among yield and some yield components by using correlation and path coefficient analysis. The experiment was carried out in the experimental field Kharke Sanandaj in 2006. In this study, 36 chickpea cultivars were used. The experimental design was Triple Lattice Design. Positive and significant relationships were found among seed yield and number of pods per plant, number of seeds per pod, biological yield and harvest index. Negative and non significant relationships were determined among seed yield and 100-seed weight, number of primary branches, days to flowering, days to first pod formation and days to maturity. According to path coefficient analysis, there were strong direct effects of the harvest index (0.901), biological yield (0.194) and number of pods per plant (0.048) on the seed yield.

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P 3.10 - Responses of 8 accessions of wild rice to drought stress at vegetative growth stage Feng F.J. (ffj@sagc.org.cn), Mei H.W., Xu X.Y., Luo L.J. Shanghai Agrobiological Gene Center, Shanghai 201106, China. Drought is one of the major abiotic stresses that severely affect crop yields worldwide. In Asian cultivated rice (Oryza sativa L.), there are two ecotypes with different responses to water condition (i.e. lowland and upland rice), in landraces and modern varieties. Whether there is differentiation of drought tolerance among wild rice accession (i.e. the variation in response of wild rice germplasm to water deficit) is an interesting question and has not been well addressed. Here, drought resistance of 8 wild rice accessions (including 7 accessions of O. rufipogon and 1 accession of O. officinalis) were evaluated at vegetative growth stage, using the approach based on PVC-pipe cultivation. All materials were grown in a conservation nursery before the experiment. Tillers were separated and transplanted in the field with single tiller per hill for about two months. Moderate seedlings with nearly same tiller numbers in each accession (8-12 tillers in different O. rufipogon accessions and about 5 tillers in O. officinalis accession) were transplanted in PVC pipes, and later treated with two watering regimes (drought stress vs. control) after grown in normal condition for three weeks. Wild rice accessions manifested obvious variations in drought tolerant abilities according to their morphological and physiological responses to drought stress. There are deferent levels of decreases in canopy sizes, different initiation time and severity of stress phenomena (like leaf rolling and leaf desiccation) under drought stress. Free proline content (FPC) in most accessions increased significantly ( p<0.01) under drought stress and was positively correlated with leaf rolling scores (r = 0.778**). Leaf water potential (LWP) decreased significantly ( p<0.01) and had negative correlations with leaf rolling scores ( r = -0.869**). Drought stress inhibited the growth of both the root and the aerial part of all accessions except for O. officinalis (Thailand) and O. rufipogon (Dongxiang). Both of them had higher volume and weight of deep root (>30cm from the soil surface). O. officinalis (Thailand) had outstanding performance (with hardly any negative symptoms) throughout the whole stress process, which maintained high leaf water potential and went without large increase of free proline content. The results from this experiment provide some confidence in further screening of drought tolerant wild rice germplasm from large set of wild rice accessions using the protocol based on vegetative reproduction.

P 3.11 - Flag leaf water use efficiency in filling stage and yield of five winter wheat varieties under different water deficit regimes Fu Z.Y., Zhou J., Hu X.J., Zhang Z.B. (zzb@sjziam.ac.cn) Center for Agricultural Resources Research, Institute of Genetic & Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China. Water use efficiency (WUE) and yield are two key indexes for drought resistance breeding of Wheat. This experiment mainly focused on the Flag leaf water use efficiency (FlWUE) in Filling stage and Yield of five winter wheat varieties (shijiazhuang 8, jinmai47, xifeng20, jing411, chang6878) under different water deficit regimes (water 0, water 1, water 2 is abbreviated to w0, w1, w2). The results showed that FlWUE and yields of five winter wheat varieties changes complexly under serious water deficit (w0), that xifeng20 which had the highest FlWUE and yield was significant with chang6878 who had the lowest FlWUE and yield under moderate water deficit (w1), and that jinmai47 had the maximum FlWUE and yield under slight water deficit (w2). In addition, the yield of five wheat varieties almost enhanced with the fall of water deficit. The yields for w0 water treatment about jinmai47and jing411 were significant with those of w2, which reveals these two varieties need to water twice in life cycle to get high yield. It shows jinmai47 fits to be cultivated at slight water deficit condition and xifeng20 adapts to moderate water deficit among five winter wheat varieties. However, these five varieties had no difference under serious water deficit although they change complexly. This research is significative for screening the drought-resistance wheat variety and guiding agricultural production in North China Plain.

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P 3.12 - Drought resistance of NERICA (New Rice for Africa) compared with Asian rice (Oryza sativa L.) and African rice (Oryza glaberrima Steud.) –Dry matter and water use in pot experiment with different fertilizer levels Fujii M. (eimfuji@ipc.shizuoka.ac.jp), Shinohara R., Ishihara S. Faculty of Education, Shizuoka University, 836 Ohya, Suruga, Shizuoka 422-8529, Japan. Recently NERICA was developed by crossing of African rice (Oryza glaberrima Steud.) and Asian rice (Oryza sativa L.) in West Africa, and is considered to be drought resistant, but the difference in reactions under dry condition is not clarified enough. In this research, NERICA, Asian rice and African rice were cultivated in the pot under flooded and drought condition with different fertilizer levels in which soil surface covered with vinyl to prevent evaporation to compare dry matter production and transpiration characteristics by weighing method and by porometer. Dry matter production and transpiration in flooded condition was high in glaberrima and drought resistant Asian rice in low fertilizer level. In high fertilizer level, transpiration in NERICA under drought condition decreased compared with under flooded condition though in other cultivars there was little decrease. Water use efficiency measured by dry matter increase and transpiration was low in glaberrima under drought condition. In low fertilizer level water use efficiency under drought condition was higher than that under flooded condition. In high fertilizer level water use efficiency in drought resistant Asian rice decreased under drought condition but some NERICA it increased. There was little difference in stomatal conductance under flooded condition in low fertilizer level, but under drought condition in low fertilizer level, it was high in glaberrima and drought resistant Asian rice, and was low in NERICA.

P 3.13 - Exploiting root-to-shoot hormonal communication to improve crop salt tolerance in tomato Ghanem M.E.1, Albacete A.2, Martínez-Andújar C. 2, Dodd I. C.3, Pérez-Alfocea F.2

(alfocea@cebas.csic.es)

1 Université catholique de Louvain (UCL), B-1348 Louvain-la-Neuve, Belgium ; 2 CEBAS-CSIC, Campus de Espinardo, E-30100, Espinardo, Murcia, Spain; 3 The Lancaster Environment Centre, Lancaster University, Lancaster, UK. Salinity decreases vegetative growth and induces leaf senescence thus decreasing the resources available for crop yield. Therefore, maintaining shoot growth and leaf functioning should be a major goal for plant breeders to minimise the economic impact of the stress. Plant hormones are good candidates to regulate those processes and grafting provides a good opportunity to directly exploit the root-derived hormonal signals for improving crop salt-tolerance. Tomato plants (Solanum lycopersicum L.) were cultivated for 3 weeks under high salinity (100 mM NaCl) and growth and leaf senescence parameters were studied in relation to Na+ and K+ accumulation and changes in five major plant hormones (abscisic acid, ABA; cytokinins, CKs, zeatin, Z, and zeatin-riboside, ZR; auxin, indolacetic acid, IAA; and ethylene precursor 1-aminocyclopropane-1-carboxylic acid, ACC) in roots, xylem sap, and leaves. Additionally, to study the influence of root-derived factors on shoot salt-tolerance, a tomato cultivar was grafted onto rootstocks from a population of recombinant inbred lines derived from a Solanum lycopersicum x S. cheesmaniae cross and cultivated under moderate salinity (75 mM NaCl). Salt-induced shoot and leaf growth reduction and leaf senescence was related to strong decreases in IAA and CKs concentrations, while ACC was the only hormonal compound increasing in leaf tissue coinciding with the onset of oxidative damage and the decline in chlorophyll fluorescence, prior to massive Na+ accumulation. Indeed, the root derived hormonal factors (Z+ZR) and ACC concentrations and their ratio (Z+ZR/ACC) were the best hormonal parameters explaining the onset and progression of leaf senescence. The grafting experiment revealed that tomato crop productivity under salinity can be improved by exploiting rootstock-derived factors regulating both leaf growth and senescence. Among these factors, the leaf xylem CKs (zeatin), ACC and K+ concentrations, and their interactions, were confirmed as key factors for increasing salt-tolerance in tomato through the regulation of the crop productivity related physiological processes. Functional approaches to disentangle these physiological correlations are in progress.

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P 3.14 - Responses of dryland wheat (Triticum aestivum L.) genotypes to drought stress during grain filling Ghobadi M. (m.ghobadi@yahoo.com), Kahrizi D., Geravandi M., Ghobadi M., Zebarjadi A. College of Agriculture, Razi University, Kermanshah, Iran. In semiarid areas of the world such as many parts of Iran, rainfall decreases and soil evaporation increases in spring when bread wheat enters the grain filling period. Wheat crops often experience water deficit and heat stress during grain growth and development, which limit productivity. Our objective was to examine the effects of postanthesis water deficits on grain yield and yield components in dryland wheat genotypes. 21 diverse dryland wheat genotypes grown under well-watered and droughted field conditions during grain filling. The results showed that drought stress during grain filling decreased significantly biomass, grain yield, the number of harvestable spikes per area unit and thousand grains weight, but the effects of stress on straw yield, harvest index, the number of spikelets and grains per spike were not significant. Drought stress during grain filling, on average, reduced grain yield by 17.95%. However, the amount of reduction varied for different genotypes. Grain yield reduction by postanthesis water deficit was mostly associated with the reduction of the thousand grains weight and the number of harvestable spikes per area unit. Grain yield had positive correlations with the number of spikes per area unit, the number of grains per spike and thousand grains weight under well-watered conditions, but under postanthesis drought stress had with the number of spikes per area unit and thousand grains weight.

P 3.15 - Assessing the role of root traits in water uptake and maintenance of plant growth in the rice OryzaSNP accessions Gowda R.P.V.1, 2, Serraj R. (R.Serraj@cgiar.org)1, Henry A.1, Shashidhar H.E.2, 3 1 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines; 2 University of Agricultural Sciences, Bangalore, India; 3 Barwale Foundation, Hyderabad, India. Root traits are considered to be important in rice crop growth maintenance under water limiting condition. The OryzaSNP panel, constituted of 20 diverse rice germplasm accessions whose genomes have been genotyped for single-nucleotide polymorphisms, has been evaluated for root traits under rainfed lowland field conditions using the monolith sampling method. In addition to root traits, several physiological and yield–related phenotypic characters were analyzed under drought and well-watered conditions. A significant positive correlation was found between root length density (RLD) at depth and grain yield under drought. RLD at depth was also correlated with other root and drought-related characters, including root number per tiller, total root length (0-45 cm), root surface area, and root volume, canopy temperature, plant height and leaf rolling score. For most genotypes, the relative distribution of total root length in the deepest soil layer was significantly increased under drought compared to the well-watered control. This result suggested a genetically variable adaptive response of root growth processes to drought stress, leading to altered root morphology and architecture. Genotypes Dular, Moroberekan and Aswina had the highest drought-induced root growth at depth. The OryzaSNP accessions were phenotyped for their pattern of root water extraction profiles in a greenhouse lysimeter facility. Substantial genetic variation was observed for water uptake between drought avoidant accessions (e.g. Dular, Moroberekan, Aswina) and sensitive cultivars (e.g. IR64). A highly significant and positive correlation was observed between water uptake, shoot biomass accumulation measured in lysimeters, and grain yield measured under lowland field conditions. Overall, these data clearly confirm that genetic differences for root depth play a key role in explaining differences in water uptake and consequently in the maintenance of plant growth and grain yield under drought. A multi-location and multi-system comparative root phenotyping analysis of the OryzaSNP panel will further clarify the importance of genotype-by-environment interaction in rice root growth and its role in plant water uptake and crop performance under drought.

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P 3.16 - Effect of superabsorbent polymers on yield and antioxidant enzymes activity of mustard (Sinapis alba L.) under drought stress Habibi D.1 (dhabibi@kiau.ac.ir), Rahmani M.2, Shirani A.H.3, Daneshian J.3, Valadabadi A.4 , Moaveni P. 4, A.Boojar M.M.5

1 Islamic Azad University-Karaj Branch, Mehrshahr, Iran; 2 Islamic Azad University-Takestan Branch, Iran; 3 Seed and Plant improvement Institute, Karaj, Iran; 4 Islamic Azad University-Shahreghods Branch, Shahriar, Iran; 5 Tarbiat Moalem University, Tehran, Iran. Superabsorbent polymers are soil amendment that absorb water and nutrients and give them to plant favorite growth. This research has been carried out with purpose of investigating the effect of different levels of water deficiency stress and superabsorbents on yield, yield components and antioxidant enzymes activity of mustard in field experiment at research station of Islamic Azad University-Karaj branch. A factorial randomized complete block design with three replications was used. The treatments included five levels of water deficiency stress [Irrigation after 80 mm evaporation from class A evaporation pan (normal), cut irrigation from stem beginning stage, cut irrigation from beginning flowering stage, cut irrigation from beginning pod stage and cut irrigation from seed filling stage] and three levels of applying superabsorbent(Concentration of 0,5 and 7%). The following traits were measured: seed yield, biological yield, harvest index, 100 seed weight, antioxidant enzymes (SOD, GPX, CAT) and lipid peroxidation marker (MDA), Di hydroxy guanozine, Di tyrosine. Results showed significant higher seed yield (5.489 ton/h), biological yield (25.09 t/h), harvest index (21.84%), 100 seed weight (0.7914 gr) in 7% polymer and irrigation after 80 mm evaporation from class A evaporation pan. Higher content of SOD, GPX and CAT obtained from cut irrigation at stem beginning stage in compare with other irrigation treatments. Superabsorbent polymers decreased antioxidant enzymes content (SOD, GPX and CAT) showing the beneficial effect of these polymers for lowering of drought stresses. Lipid peroxidation estimated as MDA content showed marked increased under cut irrigation from stem beginning stage as well as di hydroxy guanozine and di- tyrosine. Hydrogen peroxide is a toxic compound produced as a result of scavenging of superoxide radical, and its higher concentration is injurious to cell/plant resulting in lipid peroxidation and membrane injury. Based on our results superabsorbent polymers can lower toxic effects of active oxygen species hence recommended for rainfed cultivation and other water deficit condition.

P 3.17 - Effect of water deficit stress on germination and primary growth of four cultivars of soybean (Glycine max(L.)Merr) Haghighi L., Majd A. (haghighi_mehr@yahoo.com), Jonoubi P. Department of Biology, Faculty of Science, University of Tarbiat Moalem, Teharan 15614, Iran. Soybean (Glycine max (L.)Merr) is one of the most important protein and oil seed crop worldwide. In attention to time consuming and effect of uncontrolled agents like soil elements and hemisphere, study of resistance response in soybean towards water stress during germination was investigated. we used labratory methods and condition. Seed germination of four cultivars of soybean ‘Williams, Linford, L17 and M7’ were evaluated under water deficit stress by treatment of PEG 6000 concentrations for induce osmotic potentials 0, -3, -6, -9 bar. A factorial Experiments based on completely randomized design with three replications were conducted in incubator condition. During the experiment, germination percentage, radicel and hypocotyl length, fresh and dry weight of radicel, hypocotyl, plantlet and cotyledon. TWC%, MDG, rate of daily germination, percent of abnormal plantlet, ratio of hypocotyl length to radicel length and ratio of hypocotyls weight to radicel weight were measured. Variance analysis of data indicated that difference between osmotic potential had significant effect on all parameters except germination percentage. Between, cultivars Fresh weight of radicel and plantlet, percentage of abnormal plant were affected significantly. In attention to interactive effects of cultivars and different germination levels, Linnford with maximum means in radicel dry weight, cotyledon and seedling fresh weight and ratio of hypocotyl to radicel in

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fresh weight had drastic response. Hypocotyl fresh weight, TWC% averages in Williams, radicel fresh weight and germination percentage in M7 were significant respectively. Drought is one of the most important abiotic limited potential in germination and primary growth in soybean.

P 3.18 - Responses of green leaves and green pseudobulbs of C3 orchid Oncidium Golden Wish to drought stress He J. (jie.he@nie.edu.sg), Qin L. Natural Sciences and Science Education Academic Group, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk 637616, Singapore. Epiphytic orchids are directly or indirectly exposed to natural air current and solar radiation and receive only intermittent rains. These conditions produce a somewhat xerophytic environment that imposes a water deficit on orchids. Thus, tolerance to water deficit is a decisive factor in their survival. Epiphytic orchids usually have water and reserve carbohydrate storing tissues and they are often referred to pseudobulbs. Although large amount of water and carbohydrates are stored in the green pseudobulbs (GPSB), many epiphytic orchids are sensitive to prolonged water deficit. Under conditions of water deficit, photosynthetic capacities of green leaves (GL) and GPSB may be reduced. In the present study, responses of GL and GPBS of C3 orchid Oncidium Golden Wish to drought stress were first monitored by measuring the changes of water content during a 10-week drought stress period. Decrease in water content was much greater in GPBS than in GL of drought stressed-plants, indicating that the GPSB facilitated a slow reduction in the leaf water content. This finding was further supported by the result of relative water content of GL, which was still greater than 85% after 10 weeks of drought stress. For drought stressed-GL, midday chlorophyll fluorescence Fv/Fm ratio was slowly decreased from about 0.817 to 0.622 over a 10-week period. On the other hand, over the same period of drought treatment, there were no significant differences in GL chlorophyll and carotenoids content between well watered- and drought stressed-plants. These data suggested that GL of C3 orchid Oncidium Golden Wish was tolerant to drought stress, resulting from the continuous water supply from the large GPBS. However, chlorophyll and carotenoids content were significantly lower in GPBS of drought stressed-plants as compared to that of well watered-plants. These results implied that GPBS was more susceptible to drought stress than the GL and this was supported by the measurements of photochemical quenching, non-photochemical quenching and electron transport rate measured in the laboratory from the dark adapted GL and GPSB. Our results also showed that drought affected the accumulation and partitioning of carbohydrates and ultimately, the growth and development of new shoots. Since a highly integrated pattern of carbon allocation and partitioning was observed, it was concluded that the GPBS is an important regulatory organ rather than being a mere storage tissue for water and excess assimilates. The GPBS plays an important role in the survival of epiphytic orchids from drought stress.

P 3.19 - Dissecting the role of root architecture in dehydration avoidance mechanisms in rice Henry A. (R.Serraj@cgiar.org), Gowda V., Serraj R.

International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines. Root architecture and plasticity are key traits for understanding genotypic differences in rice response to water deficit. This study aimed at analyzing the relationships between root architecture and the dynamics of plant water uptake during progressive soil drying. Experiments were conducted using rice varieties contrasting for yield response to drought, in the field and in a greenhouse lysimeter facility, both under flooded and drought stress conditions. The evolution of soil moisture profiles was monitored as a function of soil depth in both environments. Interactions between root growth parameters, ability to penetrate compact soil layers, and water uptake were used to analyze the genotypic differences in dehydration avoidance and crop growth and productivity under stress. In the lysimeters, root growth at depth varied substantially among genotypes under drought, and these growth patterns were significantly correlated with plant water uptake and reduction in soil moisture at depth. In the field, the dynamics of soil water profiles, canopy development and plant water status using non-destructive measurements (NDVI, infrared thermal imaging) were con- ducted over time, as well as destructive sampling of roots and shoots. In both environments, large differences in soil water uptake were observed among genotypes that were contrasting

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in their sensitivity to drought stress. However, results from this study also suggested that variation for other root characteristics such as root hydraulic conductance, in addition to rooting depth, may be important for root water uptake by rice plants growing in drying soils. Therefore, analysis of anatomical and biochemical characteristics affecting root hydraulic conductance have been initiated to compare genotypes contrasting for response to drought. Overall, these results will be used to demonstrate the importance of genetic variation for root growth at depth for conferring drought avoidance through improved uptake of soil water under water deficit. Initial results on the integration of root architecture parameters and root hydraulic properties will also be discussed towards a better understanding of dehydration avoidance mechanisms in rice.

P 3.20 - Identification of major drought tolerance strategies in perennial ryegrass germplasm (Lolium perenne L.) from Mediterranean and temperate origins Hussain S.1 (s.hussain1@massey.ac.nz), Matthew C.1, Easton S.H.2

1 Institute of Natural Resources, Massey University, Palmerston North, New Zealand; 2 AgResearch, Palmerston North, New Zealand. Four perennial ryegrass varieties were grown fully watered or under water deficit in summer 2008 in a glasshouse study to explore drought tolerance mechanisms of this species. Plants were grown in pipes of 90 cm depth. Included in the experiment were a ‘Mediterranean’ cultivar (Medea), two New Zealand cultivars (Grasslands Samson and Tolosa), and a tetraploid breeding line closely related to G. Samson. Measurements included soil moisture content (SMC) and root dry weight (RW) for three soil depths, and shoot dry weight (SW), leaf relative water content (RWC), level of the osmolyte proline, and electrolyte leakage (EL) as a measure of cell membrane integrity. Plants of all varieties were smaller when subject to water deficit and Medea plants were small compared to the New Zealand cultivars. Medea showed marked drought adaptation, notably increased RW:SW ratio (R:S). Samson exhibited greatest% size reduction under water deficit with no water deficit adaptation detected. The tetraploid Samson breeding line showed a trend to increased RW at 55+ cm soil depth in water deficit. Plants of Tolosa had high proline levels and depleted soil moisture less than G. Samson and its related tetraploid line.

P 3.21 - Association of water uptake ability with yield performance under increasing dehydration stress in synthetic wheat Inagaki M.1,2 (m.inagaki@cgiar.org) , Nachit M.M.1

1 International Center for Agricultural Research in the Dry Areas (ICARDA), P. O. Box 5466, Aleppo, Syria;

2 Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, 305-8686 Japan.

The growing season of wheat in the dry areas of West Asia coincides with rainfall mainly from November to April. Drought stress in these areas strongly depends on residual soil water available for the reproductive growth. The water uptake abilities of three synthetic wheat genotypes and their parental variety were examined in potted soil under controlled conditions. In addition, yield performance was compared under ten rain-fed environments at two locations over five cropping seasons. Large differences were found in water uptake ability among the four wheat genotypes. These differences were reflected in reductions of both soil water content and leaf temperature after irrigation. Significant differences of the mean grain yield were also found among wheat genotypes grown in ten rain-fed conditions. Lower water uptake ability was associated with higher grain yield. Intensive extraction of water from soil during vegetative growth might increase biomass production, but leave inadequate available soil moisture for reproductive growth and grain production. The balancing of water consumption by plants with residual soil moisture over the whole growing period is a major attribute of drought adaptation in wheat.

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P 3.22 - The effect of sowing date and row spacing on yield and yield components on hashem chickpea variety under rainfed condition in ker- manshah Shamsi K. (shams2_k@yahoo.com) Islamic Azad University Kermanshah Branch, Iran. In order to investigate the impacts of sowing date and row spacing on yield and yield components of Hashem chickpea veriety, a field experiment was conducted in 2005 at farm of Dorood Faraman(Kermanshah-Iran). In this study, the sowing date in three level (6, 23 November and 6 December) and the row spacing in three level on rows (20, 30 and 40 cm) were evaluated with complete randomized block design in factorial arrangement. Results of experiment showed that there are significant differences for planting date and planting density effects of plant height, number of branch per plant, distance between 1st pod to soil, number of pod per plant, number of grain per plant, biological yield and grain yield. The also maximum grain yield belong to sowing date 6 November and row spacing 30 cm. However maximum number of pod per plant and grain per plant belong to 40 cm row spacing but higher number of pod and grain per unit area in 20 cm row spacing result in increasing grain yield in this row spacing. As result show increasing planting density resulted in decreased yield components but from the other hand increased plant number compensate decrease of yield components. Also we found that planting at 6th December had higher distance of pod from soil surface and thus easier mechanized harvesting.

P 3.23 - Characterizing the rice TPE and screening germplasm and inter-specific progenies for drought resistance in field-managed nurseries Kijoji A.A. 1, 2 (kiabuu@yahoo.com), Kanyeka Z.L. 3, Nchimbi-Msolla S.1, Serraj R.2

1 Sokoine University of Agriculture, Department of Crop science and Production, P.O. Box 3005, Morogoro, Tanzania;

2 International Rice Research Institute, Crop and Environmental Science Division, DAPO 7777, Metro Manila, Philippines;

3 International Rice Research Institute, East and Southern Africa Regional Office, P.O. Box 33581, Dar es Salaam, Tanzania.

Drought is one of the major constraints of rice (Oryza sativa L.) production in Sub-Sahara Africa due to irregular rainfall and insufficient flow water for irrigation. Characterizing the rice target population of environments (TPE) where new varieties are expected to perform is important for setting breeding priorities aiming at improving production in the rainfed areas. We carried out a survey in three major rice growing regions in Tanzania to characterize the drought patterns, by analyzing the timing, severity and frequency of drought in the major rainfed lowland areas. In addition to the experience of farmers and crop scientists, long-term climatic data and hydrology patterns were reviewed and analyzed. Experiments were conducted to identify drought resistant rice genotypes under reproductive-stage drought stress in field-managed nurseries, and to analyze the relationships between grain yield components and putative physiological traits contributing to the drought resistance. Sixty eight O.glaberima and O. sativa interspecific progenies developed at IRRI including the recurrent parental line (IR 64), IR 72, Apo and a set of selected germplasm accessions from the Oryza SNP panel, 6 NERICA lines, 23 aerobic lines and 10 local varieties, were evaluated under fully irrigated and drought stress conditions applied around the reproductive-stage. Surface irrigation was applied to supplement rainfall until booting stage (about 55 d after seedling emergence in most lines) and water was drained and irrigation stopped to induce water deficit in the stress treatment. Drought stress was maintained until the susceptible checks showed severe stress symptoms and tensiometers readings were around -60 kPa at 30 cm depth, then the trial was re-watered and drained again after flash irrigation, resulting in successive drying cycles until physiological maturity. In addition to the environmental and soil moisture parameters, the following plant traits were recorded: leaf rolling scores, leaf drying, flowering delay, panicle sterility, plant height, biomass, harvest index and grain yield. Selected germplasm from this field screening trial will be further evaluated in controlled environment to analyze the physiological traits and underlying mechanisms that control drought avoidance behavior in rice. Identification of new genetic sources and

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donors of drought resistance traits, and associated QTLs will accelerate the breeding efforts for drought-resistant rice varieties in SSA. With the knowledge of the rice TPE in Tanzania, the selected germplasm from the field managed screening nurseries will be further phenotyped in controlled environment under various drought stress scenarios at different growth stages.

P 3.24 - Seed treatments with trinexapac-ethyl induce differential drought resistance in gibbe- rellin-sensitive and insensitive wheat and barley isolines Klein J. D.1 (vcjosh@agri.gov.il), Oman A.1, Hebbe Y.1, Chandler P.2

1 Division of Plant Sciences, ARO-The Volcani Center, Bet Dagan 50250 Israel; 2 CSIRO Plant Industry, Canberra, Australia. Inhibitors of gibberellin synthesis such as triazoles and acylcyclohexanediones can induce abiotic stress resistance in plants when applied as seed or seedling treatments. We investigated seed treatments with the acylcyclo- hexanedione trinexapac-ethyl (TE) in Rht and rht3 wheat and in Sln1 and Sln1d barley, which are respectively normal (wild-type) and gibberellin- insensitive (dwarf) isolines of each grain, as a means of inducing drought resistance. Wild- type barley responded to TE at lower concentrations than wild-type wheat, with seedlings of both types having characteristic dwarfing responses of shorter stems, thicker leaves and higher chlorophyll contents. Under drought conditions, seedlings from wild-type TE-treated seeds had higher relative water content, greater membrane stability, and better recovery from stress (regrowth). Leaves of seedlings from TE-treated wild-type seeds had greater anti- oxidative capacity and higher concentrations of anthocyanin and carotenoids, which are linked with resistance to stress. Gibberellin-insensitive seedlings were resistant to drought stress even without a TE treatment, and had pigment concentrations and anti-oxidative capacities similar to wild-type seedlings from TE treatment. TE treatment of seeds of dwarf isolines resulted in seedlings that were slightly reduced in size, but drought resistance, anti-oxidative capacity, and pigment concentrations were similar to that of seedlings from non-treated seeds. Both content and sensitivity to gibberellin seem to be involved in modulating drought resistance in wheat and barley seedlings.

P 3.25 - TE and water kinetics- relation with yield components: in peanut (Arachis hypogaea L.) under drought Kumar P.R.(p.ratnakumar@cgiar.org), Vadez V. (v.vadez@cgiar.org), Nigam S.N., Krishnamurthy L. International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru- 502 324, Andhra Pradesh, India. Transpiration efficiency (TE) is an important trait for drought tolerance in peanut (Arachis hypogaea L.). The variation of TE was assessed gravimetrically using a long time interval in nine peanut genotypes (Chico, ICGS 44, ICGV 00350, ICGV 86015, ICGV 86031, ICGV 91114, JL 24, TAG 24 and TMV 2) grown in lysimeters under well-watered and drought conditions. The transpiration was measured by regular weighing of the lysimeters whose soil surface was mulched with a 2-cm thick layer of polythene beads. Transpiration efficiency in the nine genotypes used varied from 1.4 to 2.9 g kg-1 under well watered and 1.7 to 2.9 g kg-1 under drought conditions, showing consistent variation for TE among the nine genotypes. Higher TE was found in ICGV 86031 in both well-watered and drought condition and lower TE was found in TAG-24 under both the water regimes. Although the total water extraction differed little across genotypes, the pattern of water extraction from the soil profile varied among the genotypes. High water extraction within the 24 days following stress imposition was negatively related to pod yield (r2 = 0.36), and negatively related to water extraction during a subsequent period of 32 days (r2 = 0.74). By contrast, the latter, i.e., water extraction during a period corresponding to grain filling (between 24 and 56 days after flowering) was positively related to a higher pod yield (r2 = 0.33). Transpiration efficiency was significantly and positively correlated with pod weight (r2 = 0.30) under drought condition. Our data showed that under the intermittent drought regime, TE and water extraction from the soil profile during a period corresponding to pod filling appeared to be the most important traits.

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P 3.26 - Cereal production and yield in Tunisia: trends and limiting factors Latiri K.1 (kawther.latiri@gmail.com), Lhomme J.P.2, Salah H.B.H.3, Annabi M.1

1 Laboratoire d’Agronomie, Institut National de la Recherche Agronomique de Tunisie, Tunisia; 2 IRD, Institut de Recherche pour le Développement, Montpellier, France; 3 INAT, Institut National Agronomique de Tunisie, Tunisia. During the second half of the last century, a significant increase in cereal yield was observed almost all over the world, including in areas subject to drought. It seems, however, that this increase is slowing down. In Tunisia, cereals are sown predominantly in the northern third of the country, called ‘Northern Tunisia’, with durum wheat as the predominant crop. Yields are subject to high year-to-year variation and a turning point is clearly observed around the year 1966 delimitating two different periods: a first one, from the beginning of the last century to the sixties, with a low increase rate and a second one with a high increase rate. However, yields are remaining extremely low in dry years and it seems that the rate of yield increase is slowing down during the last years. As the total production of grain is the result of two distinct components (yield and harvested area), both elements are discussed separately. In Northern Tunisia, yield is highly correlated to autumn rainfall, while the correlation to spring rainfall is extremely low, which demonstrates the important role of the first stages of growth in yield elaboration. Whereas in the North of the country the sown area does not vary significantly from one year to another, in the Centre and South, where drought occurs frequently, there is a huge variation in the sown area. This is explained by the fact that sowing is postponed by farmers until the first significant rainfalls take place or even can be cancelled. Cereal production can also be diminished through a reduction of harvested areas with respect to sown areas, which is the consequence of crop failure generally due to severe drought during the growing season. Water use efficiency (defined as the ratio between the yield and the growing season rainfall) stayed almost constant for durum wheat in Northern Tunisia until the late 60 s and then increased significantly up to now. Yet some low values appear, demonstrating that there are other limiting factors than the growing season rainfall: for instance, irregular rainfall or periods of drought. Finally, the main factors limiting cereals yields are discussed and analysed in order to give way to more genetic and agronomic progress.

P 3.27 - Irrigation methods on root character and yield of cherry tomato during fruit stage in greenhouse Liang Y.L.1,2 (liangyl@ms.iswc.ac.cn), Wu Y.2, Huang M.L.2, Zou M.J.2, Wei Z.X.2, Zhu J.J.2

1 Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Re- source, No.26 Xinong Road, Yangling, Shaanxi 712100, China;

2 College of Resources and Environment, Northwest A & F University, No.22 Xinong Road, Yangling, Shaanxi 712100, China.

There is very close relationship between root system and yield, up growth root system is the basic of high yield and fine quality of mini tomato. Plot experiment was carried out to study the effects of different irrigation methods on cherry tomato root characters and yield during fruit stage basic on 6 irrigation methods (1 conventional furrow irrigation, 2 alter furrow irrigation, 3 furrow irrigation in planting row, 4 furrow irrigation in manipulating row, 5 alter furrow irrigation in early fruit stage and conventional furrow irrigation in latter fruit stage, 6 conventional furrow irrigation in early fruit early and alter furrow irrigation in latter fruit stage, with three replications in greenhouse during 2007 to 2008, in Yangling agriculture high technology industry demonstration area, Shaanxi province China, Qianxi cherry tomato was selected as indicating crops. The results indicated that root characters of cherry tomato were significantly different at 0.01 among different irrigation methods. Root growth velocity of alternative furrow irrigation in early fruit stage and conventional furrow irrigation in later fruit stage was much higher than other irrigation methods. The bleeding sap of root system and root activities reached 22.37 mg⁄min, 0.50 mg·g-1·h-1. Fruit yield per plant, cumulated yield of cherry tomato were significantly different at 0.01, fruit yield per plant of alter furrow irrigation in early fruit stage and conventional furrow irrigation in later fruit stage was significantly higher than conventional furrow irrigation and furrow irrigation in manipulating row. Cumulated

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yield was significantly higher than growth row irrigation. In conclusion, the irrigation modern of alter irrigation in early fruit stage and conventional furrow irrigation in later fruit stage could improve root growth and increase cherry tomato yield.

P 3.28 - Connection between yield and carbohydrates in developing wheat and barley grains under drought Mäkelä P.1 (pirjo.makela@helsinki.fi), Rajala A.2, Peltonen-Sainio P.2

1 Department of Applied Biology, P.O. Box 27, 00014 University of Helsinki, Finland;

2 MTT Agrifood Research Finland, 31600 Jokioinen, Finland. Drought of all environmental factors limits crop production most severely. Sucrose is the major transport and starch is the major storage carbohydrate in cereals. Under drought, the grain growth is limited due to the availability of carbohydrates resulting in small sized grains or abortion of ovaries. Even short periods of drought usually cause either abortion of florets or decrease grain filling. Our aim was to visualize the carbohydrate accumulation and link it to grain yield. The experiment was conducted in 2008 at the MTT Agrifood Research, in an open-wall greenhouse. Wheat (Triticum aestivum L., cv. Amaretto) and barley (Hordeum vulgare L., cv. Clyde) were sown into 10-L pots containing 9 kg quartz sand. Pots were fertilized with macro- and micronutrients. Control pots were watered frequently throughout the growing season, whereas drought was imposed at anthesis by withhelding watering. The experiment was conducted in a completely randomized design, with six replicates. Samples for grain cell number and carbohydrate localization were collected every second day from pollination. Phytomass samples were collected at anthesis and at maturity. Tillers and main stem were separated and hand treshed. The following parameters were established: grain yield, number of heads and grains, single grain weight, harvest index. All grains in the spike were weighed individually and their position in the spikelet/spike was recorded. Drought decreased the phytomass and number of fertile florets and grains in both cereals. Drought decreased grain cell number in wheat, especially in distal grains. Within four days from pollination some grains withered under drought. There seemed to be a relationship between the carbohydrates in the filling grains and yield in wheat, whereas that was not so clear in barley. The grain filling process of barley and wheat seems to respond differently to drought.

P 3.29 - Reduced-tillering wheat lines maintain grain yield and improve kernel weight in terminal water-stress environments Mitchell J.H.1,3 (jaquie.mitchell@csiro.au), Chapman S.1 , Rebetzke G. 2 , Fukai S.3

1 CSIRO Plant Industry, Queensland Bioscience Precinct, 306 Carmody Rd, St Lucia 4067 Brisbane, Qld, Australia;

2 CSIRO Plant Industry, G.P.O. Box 1600 Canberra, ACT, 2601, Australia; 3 School of Land Crop and Food Sciences, The University of Queensland, Brisbane 4072, Qld, Australia. The northern Australian wheatbelt extends from central NSW to central Queensland and accounts for c. 20% of Australia’s wheat crop. The region is dominated by summer rainfall so that wheat crops are grown on predominantly stored soil moisture. Conditions are favorable for early growth but water stress post-anthesis provides a major limitation to production. This, combined with rising temperatures towards the end of the grain-filling stage, often leads to the development of small-sized kernels commonly termed by industry as ‘screenings’. Reduced grain yield (GY) limits farmer profitability while high screenings have the potential to further devalue the crop. Previous studies suggest the incorporation of genes to reduce tillering reduces the production of wasteful tillers that otherwise die thereby encouraging production of larger, fertile stems, a higher harvest index and increased kernel weight (KW). Field experiments were conducted under a rainout shelter to investigate the value of the tiller inhibition (tin) gene in maintaining large kernel weight and GY under a managed terminal water-stress. Five near-isogenic lines (NILs) contrasting for high and low tiller potential and their recurrent Silverstar parent were sown at two plant densities in three contrasting water regimes. Under severe stress conditions (mean GY of 2.8 t/ha) there was no significant

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difference between NILs for GY while KW was 21% higher in the restricted tin NILs. Under mild-stress conditions (4.1 t/ha) the restricted tin NILs produced an 11% greater GY while still maintaining an 18% KW advantage over free-tillering NILs. It was only under irrigated conditions (5.6 t/ha) that restricted tin NILs produced 15% lower grain yield than free-tillering lines with no significant difference in KW. Incorporation of the tin gene into genetic material adapted to the northern wheatbelt coupled with appropriate plant density may provide scope for simultaneous improvements in grain yield and kernel weight in terminal water-stress environments.

P 3.30 - Correlation analysis of yield and yield components of Iranian safflower genotypes under different irrigation regimes Mohammadi-Nejad G.1 (g.mohamadinejad@yahoo.com), Tohidinejad E.1, Shadfar H.2, Farahbakhsh H.1, Shafea L.1, Nakhoda B.2

1 Department of Agronomy and Plant Breeding, Shahid-Bahonar University, 76169-133, Kerman, Iran; 2 Agricultural Biotechnology Research Institute, 31535-1897, Karaj, Iran.

Safflower (Carthamus tinctorius L.), is an oil seed crop belong to compositae family. Traditionally, the crop was grown for its flowers, used for coloring and flavoring foods and making dyes, especially before cheaper aniline dyes became available. It was also being used as a medicinal plant. Safflower has a strong taproot which enables it to thrive in dry climates. Safflower oil has been produced commercially and for export for about 50 years. It was being used as an oil source for the paint industry for years but nowadays, safflower edible oil is being used for cooking, margarine and salad. Iran is importing about 90% of its edible oil from different countries. Safflower can grow and produced well in dry regions with very low amount of water. In this study we evaluated the yield and yield components of 10 Iranian safflower cultivars under three irrigation intervals in 2008 at experimental field of Shahid-Bahonar University of Kerman-Iran, which is located at (56:57´, 30:16´) with the average of 140 mm annual rainfall. This study was conducted in a split plot experiment with RCBD design, with three replications. The main factor was different irrigation intervals at three levels including: 80, 110 and 140 mm evaporation from the pan class A. Ten different Iranian safflower cultivars were considered as sub plots. Results showed that Irrigation at 110mm evaporation from the pan had the best yield. It was mainly due to increase in the number of heads per plant and plant height. Correlation analysis showed that number of seed per head and plant height had the highest effect on yield after the number of heads per plant. The best irrigation treatment can be recommended as optimum level of irrigation for safflower in dry regions of Iran.

P 3.31 - Defining winter wheat drought tolerance in eastern Colorado Moragues M.1(moragues@lamar.colostate.edu), Haley S.D. 1, Byrne P.F. 1, McMaster G.S. 2, Buchleiter G.W. 2, Trout T.J. 2 1Department of Soil and Crop Sciences, Colorado State University. Fort Collins, CO 80523, USA; 2ARS-USDA, Agricultural Systems Research, Fort Collins, CO 80526, USA. Winter wheat production in Colorado is mainly limited by water availability. Winter wheat is planted soon after late summer rains, which are unpredictable in terms of amount and distribution. After winter, the wheat plant often experiences water shortage until spring rains come and finally the grain filling period is characterized by drought and heat. In this scenario, several morphophysiological traits may be important to increase winter wheat yields. To determine the relative importance of traits that contribute to yield in this environment, we studied 24 adapted wheat cultivars under five drip irrigated moisture regimes ranging from rainfed to full irrigation for traits like coleoptile length, tillering and tiller retention, water use and water use efficiency, and growth and dry matter translocation. The importance of each trait for winter wheat breeding in Colorado will be discussed.

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P 3.32 - Physiological, morphological, and biochemical aspects of water stress on yield, and yield components of bread wheat genotypes Nakhoda B.1 (b.nakhoda@abrii.ac.ir), Abbasi F.2, Shirani-Rad A. H.3, Khorrami-Vafa M. 4, Mohammadi-Nejad G.5

1 Agricultural Biotechnology Research Institute, 31535-1897, Karaj, Iran; 2 Agricultural Engineering Research Institute, Karaj, Iran; 3 Seed and Plant Improvement Institute, Karaj, Iran; 4 Razi University, Kermanshah, Iran; 5 Shahid-Bahonar University, Kerman, Iran. Iran is located in a dry and semi-dry region of the world with about 240 mm annual rainfall. Due to this fact water stress and drought are the most important abiotic stresses reducing the yield and production of crop plants in Iran. Physiological, morphological, and biochemical aspects of water stress on yield, and yield components of Iranian wheat genotypes were studied in a split-plot experiment with RCBD design and three replications at Seed and Plant Improvement Institute’s experimental field in Karaj- Iran for two consecutive years. Water treatments at five levels (100%, 75%, 50%, 25%, and 0% of crop water requirement based on climatic data) were considered as main plot and subplots were wheat (Mahdavi, Alamoot, M-73-4, M-73-11, M-73-19, and C-73-30) at six levels. Water treatments were imposed after tillering and before stem elongation in spring (growth stage 4). Canopy temperature increased significantly under water stress. Wheat genotypes with warmer canopy under control conditions (100% of crop water requirement) had higher yield and better performance under severe water stress (no irrigation after winter) too (r=0.72*). But there was no significant correlation between canopy temperature and yield under severe drought conditions (r =0.28). Photochemical efficiency of PSII (Fv/Fm) was significantly reduced under severe drought treatment. It was mainly due to the increase in Fo which led to considerable reduction in variable fluorescence (Fv). But no significant differences were found between genotypes for Fv/Fm. SPAD reading also significantly reduced under severe water stress which was mainly due to chlorophyll degradation. It seems reduction in net photosynthesis under mild drought was mainly due to stomatal closure. Increase in water stress severity caused to further reduction in net photosynthesis due to increase in mesophyllic resistance. Proline accumulation in plants’ leaves increased under water stress conditions. But no significant differences were found among genotypes. Water stress caused yield and yield components reduction in all genotypes. Data on growth, yield, and yield components are presented in the poster. Wheat genotypes Alamoot and Mahdavi had the lowest yield reduction and best performance under water stress conditions. These varieties are good for cultivation under dryland conditions too.

P 3.33 - Physiological, morphological, and biochemical aspects of water stress on yield, and yield components of barley genotypes Nakhoda B.1 (b.nakhoda@abrii.ac.ir), Abbasi F.2, Shirani-Rad A. H. 3, Yousefi A.3, Mamnooei E.3, Mohammadi-Nejad G.5

1 Agricultural Biotechnology Research Institute, 31535-1897, Karaj, Iran; 2 Agricultural Engineering Research Institute, Karaj, Iran; 3 Seed and Plant Improvement Institute, Karaj, Iran; 4 Razi University, Kermanshah, Iran; 5 Shahid-Bahonar University, Kerman, Iran. Iran is located in a dry and semi-dry region of the world with about 240 mm annual rainfall. Due to this fact water stress and drought are the most important abiotic stresses reducing the yield and production of crop plants in Iran. Physiological, morphological, and biochemical aspects of water stress on yield, and yield components of Iranian barley genotypes were studied in a split-plot experiment with RCBD design and three replications at Seed and Plant Improvement Institute’s experimental field in Karaj- Iran for two consecutive years. Water treatments at five levels (100%, 75%, 50%, 25%, and 0% of crop water requirement based on climatic data) were considered as main

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plot and subplots were barley genotypes (Torkman, Karoon×Kavir, Reyhani, C-74-9, Gorgan-4, and Kavir×Badia) at six levels. Water treatments were imposed after tillering and before stem elongation in spring (growth stage 4). Water stress led to significant increase in canopy temperature of all genotypes. Barley genotypes which had warmer canopy under normal irrigation (100% of crop water requirement) had higher yield and better performance under severe water stress (no irrigation after winter) too (r=0.72*). But there was no significant correlation between canopy temperature and yield under severe drought conditions (r =0.28). Photochemical efficiency of PSII (Fv/Fm) was significantly reduced under severe drought treatment. It was mainly due to the increase in Fo which led to considerable reduction in variable fluorescence (Fv). But no significant differences were found between genotypes for Fv/Fm. SPAD reading also significantly reduced under severe water stress which was mainly due to chlorophyll degradation. It seems reduction in net photosynthesis under mild drought was mainly due to stomatal closure. Increase in water stress severity caused to further reduction in net photosynthesis due to increase in mesophyllic resistance. Proline accumulation significantly increased under water stress conditions. But no significant differences were found among genotypes. Water stress caused yield and yield components reduction in all genotypes. Data on growth, yield, and yield components are presented. Barley genotypes Karoon×Kavir and Reyhani had the lowest yield reduction and best performance under water stress conditions. These varieties are good for cultivation under dryland conditions too.

P 3.34 - The effect of drought stress on transport trend and nutritional elements accumulation in corn plant roots Nejad S.D.B., Nejad T.S. (Tayebsaki1350@yahoo.com) Departemnet of Agriculture Science and Research, Islamic Azad University, Ahvaz Branch, Iran. The presence of high temperature averages, drought periods, salinity problems, shortage of drainage irrigation systems on farmlands of Khuzestan province (southwest of Iran) requires applying drought stress different levels (7 & 12 & 17 &22 days period of irrigation & subplot Fertilizer different levels potassium 50 & 100 & 150 kg/ha) The present research was conducted by once- fragmented plots based on complete random block design (primary treatment: different irrigation quantities and secondary treatment: plant developmental phase) with four replications in Salemi Field investigation field. The effect of irrigation cycle, developmental phase, and their interaction at level%1 on accumulation percentage of potassium, phosphorus, nitrogen, of root in different soil depths was significant; however, their effect on accumulation percentage of sodium of the root was not. The transport trend of potassium and nitrogen in different water stress levels was from tip of root toward aerial organ and by increasing the stress, this trend was increased in the root due to high mobility of both elements and contrary to potassium and nitrogen that their highest accumulation was at 0-20 cm but the highest accumulation of sodium was obtained at depth 40-60 cm. By applying more severe water stress, the accumulation of phosphorus at that depth (40-60) was not significantly decreased. The highest percentage of accumulation was observed in root tip and by applying water stress the transport of sodium toward upper part of the root was highly limited. Drought- induced stress caused reduction of biological yield, grain yield, harvest index, thousand grain weight, and number of row in corn. The difference of irrigation turns between the treatments I0 and I1 was 6 times and that of grain yield in both irrigation treatments was. Although the treatment I0 with 22 times of irrigation could be considered as the best condition throughout the season, the treatment I1 with acceptable grain yield consumed 1502 liters less than the former in one plot; hence, with regard to water deficits and drought, it must be taken into consideration.

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P 3.35 - Analysis of yield and relative drought tolerance in durum wheat genotypes under drought-stress condition Nemati I.1 (iman_nemati2000@yahoo.com), Gholizadeh S.1, Talebi R.2

1 Islamic Azad University branch Khorramshahr, Khorramshahr, Iran; 2 Islamic Azad University branch Sanandaj, Sanandaj, Iran. Present experiment was conducted for investigate of drought effect on agronomic traits and drought tolerant assessment in 20 durum wheat. Seeds were cultured in field condition at 2008. Treatments including normal (irrigation until maturity) and stress (irrigation until end of tillering) were imposed. ANOVA results show significant differences between genotypes for both normal and stress conditions in spikelt height, seed number per spikelt, plant height, dry matter and yield. Korifla and Bicrederaa-1/Azeghar-2 had the highest seed yield under normal and stress condition while Beltagy-3 and Adnan-1A had lowest. The highest TOL, MP, GMP, STI and HARM were observed for Korifla while the lowest MP, GMP, STI and HARM were observed for Adnan-1 and Haurani27. Our results show that under stress condition MP is not a suitable index for select of cultivars with high yield. So Haurani27 was identified as a cultivar has high drought tolerance but low yield potential. Haurani27 is not economic crop because it had low SSI and TOL. Korifla is more tolerant because showed higher GMP and STI.

P 3.36 - Growth analysis and water use efficiency of Alfalfa (Medicago sativa) under irrigated condition Nucci E.D.1 (edinucci@parana.inta.gov.ar), Valentinuz O.1,2

1 Instituto Nacional de Tecnología Agropecuaria, EEA Paraná. Ruta 11 km 12.5, Oro Verde (3101),

Entre Ríos, Argentina; 2 Universidad Nacional de Entre Ríos, Facultad de Ciencias Agropecuarias, Oro Verde (3101), Entre

Ríos, Argentina. Forage offer for both milk and meat production in Central Region of Argentina is related to successfully alfalfa growth during spring and summer when water deficit are common. In this study we examine the impact of supplementary irrigation on leaf area index (LAI), shoot dry matter accumulation (DM) and water use efficiency (WUE) of alfalfa. The experiments were carried out at Paraná Research Station of INTA, Argentina (31º 50’ S, 60º 31 W, 110.5 m above sea level) during two growing seasons (2005/6 and 2008/9). Bárbara SP INTA, an alfalfa cultivar belonging to latency group # 9, was sown during autumn of 2004 and 2008 using a six row experimental planter. Plots consisted of six rows 5 m long with 0.175 m between rows. Treatments consisted of i) rainfed and ii) irrigated conditions (R and I, respectively). For irrigated plots, additional water was applied when accumulated soil water was below 30% (2005/6) and 60% (2008/9) of maximum available water. LAI was calculated by multiplying total dry matter by the proportion of leaves and specific leaf area. DM was estimated by cutting all biomass in an area of 3.15 m2 and drying in stove (60℃) until constant weigh. WUE efficiency was calculated from the DM difference between treatments and divided by amount of water added by irrigation. Growing seasons greatly differed in terms of rain and potential evapo-transpiration. Without irrigation, DM was 1450 kg/ha and 480 kg·ha-1 for 2005/6 and 2008/9, respectively. In similar way, LAI was 4.6 and 0.4 for 2005/6 and 2008/9, respectively. Irrigation greatly increased DM and LAI by more than 60% in 2005/6. Drought scenario during summer 2008/9 determined that, when alfalfa was irrigated, DM and LAI increased 7 and 10 times, respectively. WUE was 11.3 and 11.8 g DM mm-1 for 2005/6 and 2008/9 growing seasons, respectively. Additional irrigation caused significant effects on DM and LAI during summer regrowths.

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P 3.37 - Phenotypic plasticity of rice (Oryza sativa L.) under drought: a case of leaf area growth in uplands Okami M., Kato Y., Yamagishi J. (junya@fm.a.u-tokyo.ac.jp) Field Production Science Center, The University of Tokyo, 1-1-1, Midori-cho, Nishitokyo, Tokyo, 188-0002, Japan. About 13% of the world’s rice production area is cultivated as upland rice where average yield is only 2t/ha. We previously suggested the importance of early vigor, i.e., leaf area growth at vegetative stage for rice yield under upland conditions. The objective of this study was to analyze the genotypic difference in leaf area growth in rice under upland conditions from the morphological aspects. Field experiments were conducted in Tokyo, Japan in 2007 and 2008. 9 (2007) or 6 (2008) cultivars were grown under upland and non-stress lowland conditions. Under upland conditions, intermittent soil drying occurred at vegetative stage in 2007, while the soil water conditions were favorable in 2008. Leaf emergence rate was lower under upland than lowland conditions. The size of 9th-leaf was larger under upland conditions for tropical japonica cultivars (IR65564-44-51, Lemont and IRAT109), while smaller for indica lowland cultivars (IR72 and Takanari), compared to lowland conditions. IR72 and Takanari produced a huge number of tillers under upland conditions in both years, but each was quite small especially in 2007. As a consequence, the plant type of IR65564-44-51, Lemont and IRAT109 little changed even under frequent mild stress and they showed vigorous leaf area growth under upland conditions. On the other hand, the leaf area growth was retarded for IR72 and Takanari under upland conditions. This study showed the diverse response of shoot morphology to water conditions among rice cultivars. Individual leaf size and tillering dynamics play pivotal roles in the plasticity of leaf area growth, which might be associated with drought adaptation and recovery growth after drought under upland conditions.

P 3.38 - Root architecture and stomatal resistance in relation with growth and yield performance of durum wheat genotypes under drought stress Outoukarte I.1, Boumaalif O.1, Price A.2, Nasrelhaq N.3, Labhilili M.4, Hadrami I.E.1

(hadrami@ucam.ac.ma)

1 Laboratoire de Biotechnologies, Protection et Valorisation des Ressources Végétales, Université Cadi Ayyad, Faculté des Sciences Semlalia, BP. 2390, 40 000, Marrakech-Maroc;

2 Institute of Biological and Environmental Sciences, University of Aberdeen, UK; 3 Institut National de la Recherche Agronomique, Settat, Maroc; 4 Institut National de la Recherche Agronomique, Rabat, Maroc. The effects of drought stress on stomatal resistance, yield and its components were studied in pot experiments using five durum wheat genotypes (Karim, Cham1, Lahn, Haurani and INRAT 69) grown under four irrigation regimes. Stomatal resistance was measured on both upper and lower surfaces of the uppermost fully expanded leaf during three main growth stages: tillering, anthesis and maturation. During anthesis, daily observations were made to determine the flowering period under each irrigation mode. After 133 days of growth, plants were harvested, plant height, shoot biomass, tiller number, tiller spikes and spike weight were determined. Analysis of variance revealed a higher genetic variability in terms of plant height, tiller number and tiller spikes. Increasing drought stress degree, yield and its components decreased dramatically. Haurani was revealed as the most yielding genotype (high tiller number, tiller spikes, grain weight, spike weight and harvest index) and INRAT 69, with long flowering time showed the lowest productivity presented by a weak harvest index, low tiller number, low grain weight and low spike weight considering all irrigation regimes. Regarding the stomatal resistance, a positive correlation was revealed with stress degree increasing during the three development stages. However, significant genotypic differences were observed only under moderate drought stress. Root and shoot growth attributes were studied simultaneously in rhizotrons system for six eight weeks. Maximum root and shoot length and root number were recorded each week during six weeks of growth. Root to shoot ratios, maximum root angle, tillering degree, root and shoot biomass were recorded at harvest. From the results obtained, genotypes characterized by high root

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to shoot dry weights and length ratios exhibited low tillering degree. Haurani showed the highest root to shoot ratios and Lahn the lowest ratios. Regarding the root number parameter, good discrimination between genotypes was obtained at 100 cm and 120 cm. Taking the data of these experiments, a genotypic variability was revealed in terms of yield and its components under different drought stress situations. Root/shoot ratios and other growth attributes recorded in rhizotrons will be used to characterize durum wheat for the tolerance to drought stress under open field conditions.

P 3.39 - Effect of early water stress and flower bud removal on growth and development of high retention cotton Paytas M.1, 3 (marcelo.paytas@uqconnect.edu.au), Fukai S.1, Yeates S.1,2

1 School of Land, Crop and Food Science. The University of Queensland, St Lucia 4072, Australia; 1 CSIRO Plant Industry, ACRI Narrabri and Cotton Catchment Communities CRC, NSW, Australia; 3 INTA EEA Reconquista, Santa Fe, 3560, Argentina. High retention Bt cotton varieties have better insect protection compared with non-Bt varieties with similar genetic backgrounds, leading to increased early boll load and retention. The higher sink demand with increased boll load on a smaller plant of Bt cotton has led to early cut-out. At this stage with increased fruit load, the rate of vegetative growth decreases, the production of new flower buds decreases and the number of aborted flowers and fruits increases. The balance between the capacity to produce assimilates and the time and rate of fruiting load or actual carrying capacity of the crop was studied with Bollgard II. Two years experiments with Bollgard ll variety Sicot 71BR (Bt cotton producing 2 insecti- cidal cry proteins) were conducted at the University of Queensland, Gatton Campus, southeast Queensland, Australia to study the impact of water stress and fully irrigated treatments on growth, development and yield of Bt and conventional varieties. The water treatments included well irrigated (WI) over the whole crop season, water stress until squaring (WSS) followed by continuous full irrigation, and water stress until flowering (WSF) followed by continuous full irrigation until the end of season. Bollgard II with high retention cotton and Bollgard II with early flower removal to generate lower retention (simulating conventional variety) were the removal treatments. The effects of water treatments were examined using rainout shelters and plastic cover of inter-row space for designated time period in different experiments. Soil water was monitored to maintain the levels of water in each treatment. Flowers removed were done during the first two weeks at early flowering. Water availability affected time to reach different key crop stages: cut-out and maturity occurred earlier in stress treatments due to associated decrease in soil water content crops. Total biomass and vegetative production, LAI and early canopy closure was significantly higher for WI followed by WSS. Without flower removal, the effect of early water stress on seed cotton yield was a reduction about 20%, however with flower removal the effect was then 5-8% of reduction in yield compared with WI treatments. This suggest that early irrigation developed a larger canopy which was important for the high retention cotton, whereas plants can be stress during early stages in conventional cotton varieties (flower removed) where source-supply is relatively large and compensation may happened compared with stressed Bt cotton.

P 3.40 - Water use efficiency of canola as affected by drought stress Rafiei M. (Rafieemasoud@yahoo.com) Khorramabad Islamic Azad University, Iran. For increasing of irrigation efficiency and water use efficiency in canola and decrease water wastes in usual methods of surface irrigation, this research was carried out in 2007. The experiments were in RCBD as split plot with four replications. Five irrigation regimes includ irrigation after 50 (control), 55, 60, 65, and 70 (high drought stress) percent depilation of field capacity (FC) were as main plots and two surface irrigations (usual irrigation of furrows and every other row irrigation) were in subplots. The results showed that there were no significant different among first three levels of irrigation regimes in seed yield, but the highest WUE were in 60%, with every other row irrigation. The performance of different every other irrigation methods did not affect seed yield. Despite

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the significant decreasing of water used in the whole growth period at the rates of 30.12% comparing with usual irrigation, yield decreasing was not significant. In this respect, the treatments of every other irrigation were increased WUE at the rates of 24.86% in comparing with control. The results in general was indicated the superiority of irrigation after 55% FC every other irrigation furrow.

P 3.41 - Biogas slurry as a seed coating media for successful pulse production in dryland farming Raman R. (ramanr_ag@rediffmail.com), Kuppuswamy G. Department of Agronomy, Faculty of Agriculture, Annamalai University, Annamalai Nagar, Tamil Nadu, 608 002, India. In dryland agriculture, pulse crops occupy an important place because of their low water requirement and ability to withstand environmental stress. Pulses as an important source of protein help to meet perhaps the most important nutritional need of the people in the developing countries. This group of crops also enriches the soil by their unique characteristic of nitrogen fixation. The importance of this group of crops has further increased in recent years due to global shortage of chemical fertilizers. This group of crops mostly grown in the marginal lands with less care than cereals that is the reason for poor yield in pulses. Pre-sowing technique such as seed coating with organic, inorganic nutrients and bio-fertilizers holds considerable promise in improving the early crop stand, thereby increasing the production level. Seed coating provides an inbuilt mechanism for seed encapsulation of certain organic, inorganic nutrients and bio fertilizer inoculums which by virtue of their immediate availability in the vicinity of seed may help to sustain the nourishing requirement of emerging seedlings. Field experiment was conducted at Experimental farm, Annamalai University, Annamalai Nagar, Tamil Nadu, and India to study the effect of seed coating with biogas slurry, inorganic nutrients and Rhizobium on mungbean (Vigna radiata (L) Wilczek). The experiment consists of nine seed coating treatments. The treatments were replicated thrice adopting Randomized Block Design. Seeds were dibbled at soft waxy stage immediately after harvest of preceding rice crop. A uniform spacing of 30/10 cm was adopted for all the treatments. Among the treatments, seed coating with biogas slurry 50%. Rhizobium 2%, super phosphate 2%, zinc sulphate 1% and cobalt nitrate 0.5% markedly increased all the growth and yield components resulting in maximum grain and haulm yield. Based on the field experiment, it may be concluded that seed coating technique holds promised as a viable low cost pre sowing technique for improving the crop stand and ultimately yields of mungbean in dryland agriculture.

P 3.42 - Effect of water deficit in growth stages on yield, yield components and grain nitrogen content of wheat cultivars in south Iran Samdaliri M.1 (aghanbarym@yahoo.ca), Malidareh A.G.2, Mobasser H.R.3 1 Department of Agriculture, Chalous Branch, Islamic Azad University, Chalous, Iran; 2 Department of agronomy, agriculture collage, Jouybar Branch, Islamic Azad University, Jouybar, Iran; 3 Department of Agronomy, Ghaemshar Branch, Islamic Azad University, Ghaemshar, Iran. Water deficit during reproductive phase cause large yield losses in wheat especially anthesis the most period can cause yield loss by decreasing grain number in spike. The objectives of this study to determine the effect of different kinds of deficit irrigations at growth stages on yield, yield components and grain nitrogen content in wheat. Application time of irrigation water is very important on grain yield in wheat cultivars. The field experiment was designed in RCBD with split plot arrangements with three replications. The experiment was carried out in agricultural research center farm in 2007. Deficit irrigation treatments were the main plot included: (I1) normal irrigation (control); (I2) cutoff irrigation at grain filling stage, (I3) cutoff irrigation at flag leaf stage; and (I4) cutoff irrigation at flag leaf and grain filling stages. There were three wheat cultivars included Fong, Chamran and Star were as sub plots. The result indicate that straw yield, biological yield, grain yield, harvest index, grain nitrogen content and spike in square meter was significantly affected by the deficit irrigation treatments. The highest and lowest grain yield 6139 and 3863 kg·ha-1 and harvest index 36% and 27% were obtained from I1 and I4, respectively. I3 produced the highest straw and biological yield whit 11216 and 17133 kg·ha, respectively. I4

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produced the most grain nitrogen content and spike in square meter. Chamran and Fong cultivars had the highest and lowest biological yield and spike in square meter, respectively. Chamran had the highest grain yield and the lowest grain nitrogen content. Fong had the highest harvest index and the lowest straw yield. Star had the lowest harvest index and the highest straw yield. I4 had the most grain nitrogen content. I1 and I4 had maximum and minimum grain nitrogen uptake, respectively. Chamran and Star cultivars had maximum and minimum grain nitrogen uptake, respectively. There was not significantly different between I3 and I1 in the grain yield. Therefore, we can use from I3 irrigation treatment (cutoff irrigation in flag leaf stage) and decrease water usage.

P 3.43 - Characterisation of root types for drought resistance in rice (Oryzasativa L.) Sarkar K. K.1, Das (Dewanjee) S.2 (suju_diya2005@rediffmail.com)

1 Department of Plant Breeding, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur - 741252, Nadia, West Bengal, India;

2 Department of Plant Breeding, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur - 741252, Nadia, West Bengal, India.

Root as a major vegetative organ may promote plant growth under water stress condition providing desirable root geometry with best combination of its component traits. In the present investigation 13 genotypes namely Dular, Panke, Pusa 312, IR 30, IR 50, IR 64, Satabdi, Rasi, Aditya, Browngora, IET 826 and Bandana were evaluated for root traits by growing them in glass plates under osmotic stress (-0.25, -0.50 and -1.0 MPa, Polyethylene glycol) and Polyvinyl chloride (PVC) pipes. The data for shoot length (cm), root length (cm), root diameter (mm), were taken from 11 days glass plates grown seedlings. The data for maximum root length (cm), root volume (cc), fresh and dry root weight (g), dry shoot weight (g) and estimated root-shoot ratios were taken from 65 days old plants grown in PVC pipes and analysis of data revealed a range of minimum (68.8%) heritability for fresh root weight and maximum (86.2%) for root length while maximum genetic advance was shown by dry root weight (82.97%) and minimum for root length (34.15%). Most of the traits showed significant associations among themselves. On the basis of the two experiments three genotypes (Dular, Browngora, Aditya) were found as favourable parents while IR 64, IR 30 and Satabdi as poor parents under water stress conditions and these parents were mated in diallel combinations without reciprocals for assessment of inheritance of the root traits and identification of promising hybrids with favourable heterotic effect. Root traits were found to be influenced by both additive and non-additive gene actions. Dular was identified as best general combiner for all the root traits. The two hybrids (Dular×Aditya) and (Satabdi×IR 64) appeared to be most promising for presence of a desirable combination of root traits. Maximum heterosis with high per-se performance for the root traits as well as yield was found in F1, (Dular×Aditya).

P 3.44 - Does DREB1A “work” in peanut? A synthesis of phenotypic results obtained on yield and yield components of DREB1A events Vadez V. (V.VADEZ@CGIAR.ORG), Rao S., Bhatnagar-Mathur P., Devi J.M., Laroche S., Sharma K.K. International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru 502324, Andhra Pradesh, India. We assessed the putative role of a transcription factor, DREB1A driven by a stress inducible rd29A promoter both from Arabidopsis thaliana, on transpiration efficiency (TE) and water extraction from lysimeters (long and large PVC tubes filled with soil and mimicking a real soil profile). Our approach was to thoroughly assess whether transgenic DREB1A event derived from wild type variety JL24, which is known for its relative drought sensitivity, would have increased values in traits putatively related to a better yield under stress conditions, prior to assess a yield response per se. The yield under both terminal and inter- mittent stress conditions was assessed in two separate experiments, using selected events. Transpiration efficiency was assessed during several experiments and several events were consistently found having higher TE that JL24, i.e. RD2 and RD33. These promising DREB1A events when compared with breeding materials also known to have large TE were found to be at par or above. The selected events were advanced to T5 and T6 generation, and further evaluated for their water capturing

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capacity and yield response under water stress conditions in a lysimetric system, i.e. PVC tubes of of 1.2 m and 20 cm diameters, filled with soil and weighable. We found that all events had similar volume of water used and pattern of water extraction under well watered conditions, which were related to similar pattern of root development in the soil profile. However, under the influence of drought stress, the water uptake in several events was up to 30% higher than in JL24, and this was related to a larger root development in the transgenics at all depths. In a first yield response experiment, where a terminal drought was imposed, i.e. irrigation suppressed at 40 days after sowing, none of the transgenics had higher yield than the wild type under water stress, although 2 events had 16 and 23% higher yield under well-watered conditions. In a second experiment, where an intermittent stress was imposed by re-watering 1L water to drought stress plants at 6, 9, and 12 weeks after stress imposition, 3 transgenics had a yield about 30-40% higher yield than the wild type, whereas there was no significant differences under well-watered conditions. Efforts are ongoing to confirm these observations, along with breeding efforts to cross most promising events with superior breeding material and test the value of introgressing DREB1A into different genetic backgrounds.

P 3.45 - Carbon exchange rate in maize inbred lines under post-flowering water deficit Valentinuz O.1,3 (ovalenti@parana.inta.gov.ar), Eyherabide G.2, Cabello N.3, Angelini D.3

1 Instituto Nacional de Tecnología Agropecuaria, EEA Paraná, Ruta 11 km 12.5, Oro Verde (3101),

Entre Ríos, Argentina; 2 Instituto Nacional de Tecnología Agropecuaria, EEA Pergamino, Buenos Aires, Argentina; 3 Universidad Nacional de Entre Ríos, Facultad de Ciencias Agropecuarias, Oro Verde, Argentina. High rates of dry matter accumulation from flowering (R1) to physiological maturity (R6) are essential to increases yield potential in maize hybrids. Thus, selection by stay green (i.e., the ability to maintain a green and functional leaf area) has been a prime target for crop improvement and it continues to be an avenue for increasing the total amount of carbon fixed by maize crops. Water deficit often accelerates the progress of senescence and limit the assimilate supply during advanced reproductive stages. Maintaining high carbon exchange rates (CER) after flowering plays a significant role in functional stay green. The objectives of this work were i) to study the progress of carbon exchange rate of maize inbred lines growing under potential conditions, ii) to quantify the impact of water deficit during reproductive stages on CER, and iii) to evaluate the impact of saving water by thinning plants during reproductive stages. Two experiments were carried out at Paraná Research Station of INTA, Argentina (31º 50’ S, 60º 31 W, 110.5 m above sea level) during 2008/9 maize growing season. Both experiments included twenty inbred lines from maize improvement program of INTA. Experiment I (E1) consisted of pails placed in the field under a hydroponic system where nutrient solution was automatically supplied three times per day. Treatments were i) well-watered, and ii) water deficit after R1. Water deficit treatment was created by supplying 50% of daily transpiration from 2-4 days before starting the treatment. Experiment II (E2) consisted of three rows plots where each inbred line was bordered by two rows of commercial hybrid. Plots were irrigated from planting to ten expanded leaves stages. Treatments were i) control, and ii) thinning (i.e., cutting to ground level all plants in row # 3 when commercial hybrid reached R2). CER of the ear leaf was measured from 41 days before R1 to 30 days after R1 in Exp1, and from R1 to 23 days after R1 in Exp2. CER increased steadily until R1 in all inbred lines and the lowest variability for CER was observed in R1. Inbred lines showed a different response to water deficit as indicated by a significant inbred x treatment interaction. Meanwhile a group of inbred lines maintained comparable CER values under both water treatments, another group showed a faster decline as growing season progressed. In Exp2, compared to control, plant thinning increased CER from 16 (29 vs. 25 mol CO2 m-2 s-1) to 25% (12 vs. 8 CO2 m-2 s-1) days after R1.

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P 3.46 - Growth response of Acer truncatum to periodic changes in the water supply at different stages of its annual growth period Wang J.X.1 (jwang118@126.com), Wang J.1, Wang M.C.2 1 College of Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China; 2 College of Forestry, Northwest A & F University, Yangling, Shaanxi 712100, China. Although numerous studies have examined the effects of water stress on trees, few of them have compared the response of trees to drought at different stages of their annual growth period. We conducted a simulated drought experiment to test the sensitivity of Acer truncatum saplings to variations in the soil water content during different stages of their annual growth period. The pot experiment was conducted in a rain-free shelter using one-year old Acer truncatum saplings. The annual growth period of the saplings was divided into three growth stages by means of a logistic curve according to the height growth of Acer truncatum. Drought stress during the different growth stages was simulated by adjusting the soil water content in the pots according to a second-order regression general rotation and combination design that included five different soil water contents: 100%, 87.84%, 70%, 52.16% and 40% of field capacity. The results showed that although Acer truncatum is a species with strong drought resistance, its height growth and basal diameter growth were very sensitive to the timing of water stress, but the most sensitive stages was different, for height growth it was in the early growth stage and for basal diameter growth it was in the accelerating growth stage. The optimum soil moisture for roots growth of Acer truncatum was 74.05% of field capacity in the early growth stage, 84.89% of field capacity in the accelerating growth stage, and 44.93% in the late growth stage. In particular, there was a proliferation in the growth of fine roots at this moisture level. Total biomass production as well as the biomass production of roots, leaves and branches+stems varied according to the timing of water stress. The optimum soil moisture content for dry matter production was 60.78% of field capacity in the early growth stage, 64.62% of field capacity in the accelerating growth stage, and 73.37% in the late growth stage. A statistical model was obtained by the graded approach of multiple indexes. The model can be used to predict and control the growth effects under the conditions of different water supply at different stages of the annual growth period.

P 3.47 - Transpiration and stomatal conductance of Platycladus orientalis and Robinia pseudoa- cacia young tree at steady soil water stress during different stages of its annual growth period Wang J.X.1 (jwang118@126.com), Wang J.1, Wang M.C.2 1 College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; 2 College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China. In order to probe the physiological response of trees to drought, we conducted a simulated drought experiment to determine the relationship between soil water potential and transpi- ration rate and stomatal conductance at different growth stages under the steady soil water stress conditions. The pot experiment was conducted in a rain-free shelter. The annual growth period of the saplings were divided into three growth stages by means of a logistic curve according to the height growth of P. orientalis and R. pseudoacacia, respectively. Drought stress during the different growth stages was simulated by adjusting the soil water content in the pots according to the weight that included five different soil water contents: 100%, 87.84%, 70%, 52.16% and 40% of field capacity. The results showed that the influence of steady water stress to average transpiration rate is different not only in species, but also in water stress intensity and growth stages. The transpiration rate of R. pseudoacacia decreased as the soil water potential decrease, but there was a peak value for P. orientalis at the range of soil water potential -0.041 MPa – -0.648 MPa both during the early growth stage and late growth stage. The threshold value is –0.061 MPa during the early growth stage and -0.120 MPa during the late growth stage. The minimum transpiration rate appeared at about 16:00 h, and two peak values appeared at 10:00 h and 14:00 h for the two species during the daytime. There was a significant difference between Gs at different treatments of soil water potential for the R. pseudoacacia. Mean Gs for the R. pseudoacacia decreased as the soil water potential decrease, but the threshold value of stomatal conductance sharp declined was at soil water potential -0.061 MPa. The variations of stomatal

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conductance for P. orientalis hadn’t significant difference in the range of soil water potential -0.041 MPa – -0.648 MPa. P. orientalis has a very strong ability in maintaining turgor pressure, dehydration endurance and drought resistance.

P 3.48 - Alternate partial root-zone irrigation enhances nitrogen uptake and optimizes nitrogen distribution in the canopy of tomatoes Wang Y.S.1 (yawa@life.ku.dk), Liu F.L.1, Jensen C.R. 1, Andersen M.N. 2

1 Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen, Hoejbak- kegaard Allé 13, DK-2630 Taastrup, Denmark;

2 Department of Agroecology and Environment, Faculty of Agricultural Sciences, University of Aarhus, P.O.Box 50, DK-8830 Tjele, Denmark.

Alternate partial root-zone irrigation (PRI), a novel water-saving irrigation strategy, has been shown to increase water use efficiency (WUE) by 30%-100% with a slight yield reduction as compared to fully-irrigated (FI) controls. However, its advantages in terms of improving WUE, maintaining yield and nitrogen (N) uptake in comparison with its counterpart conventional deficit irrigation (DI) using the same amount of irrigation volume remains largely elusive. In this study, the comparative effects of PRI and DI on WUE, N uptake and partitioning in tomato plants were investigated. The plants were grown in split-root pots and the soil was parallel-labeled with 15NH4

+ and 15NO3

-. Results showed that both PRI and DI saved 25% water, while led to 10.0% and 17.5% decreases in dry biomass, respectively, as compared with the FI plants. WUE was the greatest for the PRI plants and followed by the DI plants, and was 18.6% and 10.8%, respectively, higher than that of the FI plants. The increases of WUE in the PRI and DI plants was accompanied by an increase of the δ13C in the plant biomass as compared with the FI plants, suggesting that the improvement of WUE in the PRI and DI plants was a result of long-term optimization of stomatal control over gas exchanges, especially for the PRI plants. During the experimental period, plant’s N uptake was the highest in the FI treatment, followed by the PRI, and the lowest in the DI treatment. A similar trend of 15N recovery was observed. Most interestingly, PRI plants consistently allocated more N into the upper leaf layer, particularly compared to the FI plants, and which may indicate a greater assimilation rate in those plants. It is concluded that PRI enhances N uptake and optimizes N distribution in the canopy, both might have contributed to the high WUE in the plants.

P 3.49 - Increasing water use efficiency (WUE) in tomato (Solanum lycoper- sicum L.) via abscisic acid overproduction White C.A.1 (sbxcw2@nottingham.ac.uk), Smeeton R.1, Thompson A. J.2, Taylor I.B.1

1 Plant Sciences Division, School of Biosciences, The University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK;

2 Warwick HRI, University of Warwick, Wellesbourne, Warwickshire, CV35 9EF, UK. Breeding plants that can produce equivalent growth with reduced water input (improved water use efficiency (WUE)) is necessary for sustained future crop production. Water deficit induces redistribution and synthesis of the phytohormone abscisic acid (ABA), thereby restricting stomatal opening and limiting water loss. Using tomato as a model crop, we have shown that it is possible to manipulate stomatal behaviour in order to improve WUE by increasing ABA production under optimal conditions. ABA is synthesised via cleavage of oxygenated carotenoids (xanthophylls). This work involves tomato genes encoding three enzymes in the ABA biosynthesis pathway: 9-cis-epoxycarotenoid dioxygenase (NCED) which can catalyse the oxidative cleavage step; β-carotene hydroxylase (BCH) which can catalyse the conversion of β-carotene to zeaxanthin; and phytoene synthase (PSY) which can produce phytoene from two molecules of geranylgeranyl diphosphate. It has been established that tomato lines over-expressing a LeNCED1 gene construct had increased ABA accumulation and improved WUE (Thompson et al., 2007). ABA production may be limited in some tissues by the supply of precursors; in order to increase xanthophyll precursor pool size, tomato lines over- expressing LeNCED1 and LeBCH2 have been combined. These double transgenics produce more ABA and have higher WUE than either of the single transgenic

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parental lines. Despite this, preliminary results indicate that grafting of these double transgenic root stocks onto WT scions does not appear to significantly affect stomatal conductance, and thus it is the ABA synthesized in the shoot that leads to restricted stomatal opening in these double transgenics. Since root tissue has a much more limited supply of carotenoids than that found in green shoots, it is hypothesized that further manipulation earlier in the pathway is necessary to increase ABA synthesis sufficiently to generate a root-to-shoot signal. Transgenic tomatoes over-expressing the LePSY1 gene have relatively large amounts of both lycopene and β-carotene in their roots. To increase further flux through the pathway, triple transgenic lines simultaneously over-expressing LePSY1, LeBCH2, and LeNCED1 genes have been created. Experiments will be performed to establish if these triple transgenic root stocks will synthesise enough root sourced ABA to have an impact on stomatal behaviour, and increase WUE, when grafted onto wild-type scions.

P 3.50 - Sorghum transpiration efficiency Xin Z.G.1 (Zhanguo.xin@ars.usda.gov), Wang M.L.2, Aiken R.3, Burke J.1 1 USDA-ARS, 3810 4th Street, Lubbock, TX 79415, USA; 2 USDA-ARS, 1109 Experiment Street, Griffin, GA 30223, USA; 3 KSU, NWREC, 105 Experiment Farm Road, Colby, KS 67701, USA. Declining freshwater resources, increasing population, and growing demand for biofuels pose new challenges for agriculture research. To meet these challenges, the concept “Blue Revolution” was proposed to improve water productivity in agriculture. The central goal of the Blue Revolution is to produce “more crops per drop” out of the available soil water. Sorghum [Sorghum bicolor (L)] is the fifth most important grain crop, providing staple food and fodder for arid and semi-arid regions of the world. As a C4 species, sorghum has the highest water use efficiency among crop plants and is likely to become increasingly important in face of the warmer and dryer trend of global climate. Recently, sorghum has emerged as an important biofuel feedstock. In this regard, sorghum is particularly advantageous over other plants due to its superior tolerance to water deficit stress and low soil fertility because it can be grown in marginal lands that are not otherwise suitable for food and fiber production. Sorghum is commonly grown under rain-fed conditions in the Southern Plains in the US and other semi-arid regions in the world. Thus, its production is strongly affected by the availability of soil water during growing season. Enhancing transpiration efficiency (TE), defined as biomass accumulation per unit water transpired, may be an effective approach to increase sorghum yield in arid and semi-arid regions under no or limited irrigation. We surveyed 340 sorghum accessions for variation in TE. Twenty-five lines were selected to conduct re-confirmation studies at two locations that have different experimental conditions and water regimes. Significant variation in TE was identified at both locations. Genotyping analysis with SSR markers clustered these 25 lines into several groups. While most lines displayed different rank in TE at the two locations, several lines with consistently greater or less TE were identified. TE based on biomass production was strongly correlated with increased biomass accumulation rather than reduced transpiration. Gas-exchange analysis indicated that decreased internal CO2 concentration and enhanced PEP carboxylase activity may contribute to the increase in TE. Biomass accumulation was positively correlated with the ratio of leaf area to root fraction of total biomass. The results indicate that although TE is strongly influenced by environment, considerable genetic variation in TE exists in the sorghum germplasm collection and sorghum cultivars or hybrids with enhanced TE can be developed for high grain yield or biomass production.

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P 3.51 - Increase in water use efficiency and grain yield through the manipulation of harvest index in rice Yang J.C. 1 (jcyang@yzu.edu.cn), Zhang J.H.2 (jzhang@hkbu.edu.hk) 1 Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yang-

zhou, Jiangsu, China; 2 Department of Biology, Hong Kong Baptist University, Hong Kong, China. A major challenge in rice (Oryza sativa L.) production is to enhance water use efficiency (WUE) and maintain or even increase grain yield. As the grain yield is the product of harvest index and total above-ground biomass, either increase in transpiration efficiency (the ratio of biomass production over transpiration) or increase in harvest index would improve grain yield and WUE. However, transpiration efficiency has been shown to be fairy constant for a given species in given climate, and higher WUE is often a trade-off lower biomass production. Harvest index has been shown a variable factor in crop production, especially in cases where whole plant senescence of rice is unfavorably delayed due to over-use of nitrogen fertilizers, adoption of lodging-resistant cultivars that stay “green” for too long, and introduction of hybrid rice which is too vigorous. This paper discussed the possibility to increase WUE without compromising grain yield through the manipulation of harvest index in the crop. Our results showed that several practices, postanthesis controlled soil drying, alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially enhance WUE and maintain or even increase grain yield of rice, mainly via improved canopy and enhanced remobilization of pre-stored carbon reserves from vegetative tissues to grains. We conclude that proper field practices hold great promise to increase crop water productivity through enhancement in harvest index.

P 3.52 - The effect of drought stress on yield, yield components and seed oil contents of three cultivars of rapeseed Zarei G.1 (zareigholamreza@yahoo.com), Dehghani S. M.2 1 Islamic Azad University, Maybod Branch, Iran; 2 Islamic Azad University, Maybod Branch, Iran. Drought, salinity, heat and freezing are environmental conditions that cause adverse affects on the growth of plants. Water deficit more than other stresses limits the growth and productivity of crops. Without sufficient water to maintain transpiration, leaf temperature can rise above their optimum for metabolism. Therefore, plants under low water availability are more prone to heat stress, too. Seed yield of Brassica napus decreased due to drought stress. The effect of drought stress is a function of genotype, intensity and duration of stress, weather conditions, growth and developmental stages of rapeseed. The occurrence time is more important than the water stress intensity. Water deficiency has adverse effect on vegetative and reproductive stages of oil seed rape crops. The occurrence time and intensity of drought differ annually in field. The growth, especially reproductive growth of rapeseed is exposed to drought stress in many areas of Iran. Hence, the objective of this field experiment was to examine the effects of irrigation interval on yield, yield components and oil seed content consists of oil quality and oil quantity. An annual field experiment was conducted on a sandy-loam with pH=7.8 and EC=2.3 dS/m at Islamic Azad University, Maybod Branch in the center of Iran (29° 52´ W latitude, 52° 55´ E longitude). Its height is 1234 meters. Mean annual rainfall, temperature and humidity are 60 mm, 19.3℃ and 32.7%, respectively. A split-plot experiment laid out in RCB design with four replications. The irrigation interval was placed in the main plots including: I1 : 7days, I2 : 10 days and I3 : 14 days and okapy, zarfam and sarygol cultivars were as subplot. Individual plots consisted of 4 rows, 4 m long and spaced 20 cm apart. Seeds were planted 3 cm deep on 29 september 2006. Fertilizer was applied based on soil testing for all treatments, N:P:K fertilizers applied in rates of 200:80:80 kg/ha, respectively.P , K and 1/2 of N applied per plant and incorporated. Other 1/2 of N used at the beginning of the flowering. Irrigation treatments applied on 6 march 2007 after rosette stage. Plants were irrigated

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every 7, 10 and 14 days, consuming 6750, 5250 and 4500 m3/ha/season, with 9, 7 and 6 times of irrigation, respectively. Grass and broad leaf weeds were hand weeded during the growth season. Final harvests were carried out on july 2007. Observations were carried out on 2 central rows and 0.5 m from both ends of the rows was left as it represented the border effect. The following measurements were carried out: seed yield, the number of lateral branches, plant height, harvest of siliques per plant, the number of seeds per silique and 1000-seed weight. Seed oil quantity and quality were determined by succelet and gas chromatography methods, respectively. Seed yield: There were significant differences in seed yield amongst the irrigation intervals and cultivars. The 7 days (3374 kg/ha) and 10 days (3046 kg/ha) interval treatments produced a significantly higher seed weight than 14 days (2652 kg/ha). sarigol (3294 kg/ha) and zarfam (3238 kg/ha) produced a significantly higher seed yield than okapy (2836 kg/ha). Yield components: The effect of irrigation intervals were significant on the mean of siliques per plant. On the 7, 10 and 14 days number of siliques per plant were 291.07, 290.77 and 257.1, respectively. Significant differences in the mean of siliques per plant were observed amongst the cultivars, too. Sarigol (318.3) produced a significantly higher number of siliques than zarfam (263.9) and okapy (256.7). significant differences were found in the mean number of seeds per silique amongst the cultivars but there was no significant difference amongst irrigation intervals. Zarfam (27) produced more seeds per silique than okapy (26.46) and sarigol (24.33). The effect of irrigation intervals were not significant on the stem height. On the 7, 10 and 14 days stem height were 133.25, 128.98 and 126.63 cm, respectively. But there was significant difference amongst cultivars. Sarigol(135.17cm) and zarfam (134.86cm) had significant difference with okapy (118.83cm). The irrigation intervals were not significant on the number of latral branches. On the 7, 10 and 14 days number of latral branches were 9.7, 10.21 and 9.41, respectively. But there were significant differences amongst cultivars. Sarigol (10.51) produced a significantly higher number of branches than zarfam (9.63) and okapy (9.18). There were significant differences in 1000-seed weight amongst the irrigation intervals and cultivars. The shortest interval (7) (3.74 gr) produced highest 1000-seed weight than 10 days (3.6 gr) and 14 days (3.38 gr). Zarfam (3.82 gr) produced a significantly higher 1000-seed weight than sarigol (3.47 gr) and okapy (3.43 gr). Seed oil content: The irrigation intervals and cultivars were not significant on seed oil content and fatty acids. On the 7, 10 and 14 days seed oil percentages were 37.58%, 38.30% and 35.93%, respectively and on the sarigol, zarfam and okapy were 37.58%, 37.58% and 35.51% respectively. 4 fatty acids measured in seed oil consist of : palmitic acid, oleic acid, linoleic acid and linolenic acid. The effect of irrigation intervals and cultivars were not significant on the fatty acids. The mean of fatty acids were: palmitic acid: 4.12%, oleic acid: 84.24%, linoleic acid: 9.14% and linolenic acid: 2.5% It is concluded from the present study that drought stress mainly decreases seed yield by reduction of the silique number per plant. 7 days interval and sarigol cultivar produced the highest seed yield.

P 4.01 - Effect of drought stress on seed embryo axis phosphatase activities during early stages of germination of two bread wheat (Triticum aestivum) cultivars Afshari R.T. (tavakkol@ut.ac.ir) Department of Agronomy & Plant Breeding, University of Tehran, Karaj, Iran. Drought resistance is very important for plant survival. Phosphatase enzymes are widely found in plants. These enzymes are responsible for dephosphorelation of organic phosphate and altering it to mineral phosphate. Germination experiments were conducted in two bread wheat cultivars (Sardari & Alvand) under simulated drought conditions using different polyethylenglycol concentrations (0, -4, -8, -12, -16 bars). Drought stress decreased germination indices. For assessing phosphatase enzymes activities in drought resistant and susceptible cultivars, an experiment was conducted under osmotic conditions with three replications using a completely randomized design. Factors were including cultivars, osmotic potentials, and seed imbibitions time. Results showed that drought stress caused of increasing in phosphatase enzymes (Acid & alkalin). Also, with increasing osmotic potential to -12 bars, phosphatase enzymes activities increased. This increasing enzyme activity was much more in drought resistance cultivar (Sardari) than susceptible cultivar (Alvand). Acid and alkalin phosphatase

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activities in both cultivars (drought resistant and susceptible) increased with increasing of seed imbibition time. In this experiment the highest activity for phosphatase enzymes was detected at 18 hours of seed imbibition. However, the activity of acid phosphatase was significantly higher than alkalin phosphatase.

P 4.02 - Silicon mediates changes to some physiological and enzymatic parameters symptomatic for oxidative stress in wheat (Triticum aestivum L.) under drought stress Ahmad S.T.1 (sara_taleahmad@yahoo.com), Haddad R.2

1 Department of Physiology and Proteomics Agricultural Biotechnology Research Institute of Iran (ABRII), Iran;

2 Department of Agricultural Biotechnology, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran.

Drought stress usually causes a decrease in crop production. Silicon is one of the important elements of plants, and plays an important role in tolerance of plants to environmental stresses. The effect of exogenous silicon (Si) were investigated on the activities of the antioxidant enzymes including of CAT, SOD, APX, POD and RWC, chlorophyll and soluble protein content in wheat (Triticum aestivum L.) to drought stress. A factorial experiment was performed in a completely randomized design with three treatments including of control, drought and silicon-drought (1 mmol silicate sodium kg) in green-house. The result indicated that silicon partially offset the negative impacts of drought stress with increased the tolerance of wheat by rising SOD, CAT, APX and POD activities and soluble protein content in both cultivars. In contrast, drought stress considerably was decreased RWC, chlorophyll and soluble protein contents. There was no observed significant difference in CAT activity between the ‘drought’ and ‘control’ treatments for both cultivars. The concentrations of H2O2 were progressively enhanced by drought stress, but were significantly suppressed by amendment with Si. Based on the present work, it can be concluded that Si alleviates drought stress by preventing oxidative membrane damage with increase antioxidant enzyme activities in wheat.

P 4.03 - Osmotic adjustment effect of Triticum aestivum L. under drought stress by exogenous silicon Ahmad S.T.1 (sara_taleahmad@yahoo.com), Haddad R.2

1 Department of Physiology and Proteomics Agricultural Biotechnology Research Institute of Iran (ABRII);

2 Department of Agricultural Biotechnology, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran.

Glycine betaine and proline are two major organic osmolytes that accumulate in a variety of plant species in response to environmental stresses. Although their actual roles in plant osmotolerance remain controversial, both compounds are thought to have positive effects on enzymes and membrane integrity along with adaptive roles in mediating osmotic adjustment in plants grown under stress conditions. The present experiment, the effects of silicon were investigated on relative water content (RWC), total protein and chlorophyll and osmolyte contents (proline and glycine betaein in two wheat (Triticum aestivum L.) genotypes differing in their sensitivity to water deficit (stress tolerant named verynack and stress susceptible named pishtaz) to drought stress on osmotic potential (-1.0 MPa). A factorial experiment was performed in a completely randomized design with three replication using treatments including of control, drought and silicon-drought. Result showed that drought stress is caused to decreas of RWC, total protein and chlorophyll contents in both genotypes, but proline and glycine betaine contents were increased in the such condition. Application of silicon in the medium caused to increased the glycine betaine and proline contents, also then was affected to increas of the RWC, total protein and chlorophyll contents, compared to non-silicon treatment. The protective effect of Silicon was observed to be more in Verynack than Pishtaz. It may be concluded that to reduce the damaging effect of stress by elevating the contents of both proline and glycine betaine, improving the water status and minimizing the injury to membranes. Searching the available academic

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reference, this is that first experiment to analysis the effect of silicon on the content accumulated osmolyte (praline and glycine betaine) on the whar under drought stress.

P 4.04 - Optimising water use efficiency through generating random variation in the rate of abscisic acid biosynthesis Awan S.1 (s.awan@warwick.ac.uk), Taylor I.B.2, Thompson A. J. 1 1 Warwick HRI, University of Warwick, Wellesbourne, Warwick, CV35 9EF, UK; 2 Plant and Crop Sciences Division, University of Nottingham, Leicestershire, LE12 5RD, UK. Abscisic acid (ABA) is a vital phytohormone helping plant survival under stress conditions. 9-cis-epoxycarotenoid dioxygenase (NCED) is an important regulatory enzyme for the synthesis of ABA. Use of the powerful promoters RuBisCo small subunit (rbcS) and the Gelvin chimeric ‘super promoter’ (sp) to drive expression of a LeNCED1 transgene resulted in increased synthesis of ABA and increased water use efficiency but with some deleterious effects including poor seed germination and delayed establishment (sp), and slow growth rate (rbcS). Here a transposon-based system (the maize Activator/Dissociation, Ac/DS) is being used to generate variation in NCED gene expression in tomato plants to create milder genotypes with improved WUE but with better seed germination, establishment and growth. The presence of the Ac element allows the transposition of the non-autonomous Ds1::histoneH2A::LeNCED1::Ds2 element to new positions in the genome where the activity of the histone H2A promoter may be altered. Southern blot analysis has shown that the Ds1::histoneH2A::LeNCED1::Ds2 has jumped to various positions in the genome. For the stable integration of the Ds1::histoneH2A::LeNCED1::Ds2 element the Ac element is then removed by segregation. Following this transposition strategy, screens have been carried out and many individual plants with low stomatal conductance have been selected. Progeny of the selected plants have low stomatal conductance, which shows that the Ds1::histoneH2A::LeNCED1::Ds2 has been stably integrated and is heritable. True-breeding lines will be developed and screened for low stomatal conductance, high ABA concentration and the presence of stable Ds1::histone H2A::LeNCED1::Ds2. Optimal increases in ABA will be selected and characterized in the context of growth, yield and crop water productivity.

P 4.05 - Transcript profiling and functional analysis of Annexin multigene family in rice under drought stress Barthakur S. (sbthakur@yahoo.com), Kumar R. National Research Center on Plant Biotechnology, Indian Agricultural Research Institute Campus, Pusa New Delhi 110 012, India. Calcium is a universal signal in eukaryotic cells, and diverse signaling pathways in plants include an increase in the concentration of cytosolic Ca2+ in at least one of the steps. Included among the calcium binding proteins that transducer these calcium signals into an adaptive response is the annexin gene family. Annexins are a multigene and multifunctional family in most plant species involved in a wide variety of essential cellular processes. Recent reports show that they also play an important role in plant stress response. In Arabidopsis thaliana there are eight different annexins (AnnAt1-8), which range from 29% to 83% in deduced amino acid sequence identity. We reported earlier that expression of eight annexins in Arabidopsis is differentially regulated by exposure to salt, drought, high and low temperature using real time RTPCR, indicating a likely role for this gene family in stress response. A recent database search of rice gene annotation resources revealed presence of twelve and six locus containing annexin domain in japonica and indica rice respectively. Towards functional characterization and clarifying the role of annexins from rice, we used RTPCR, Northern and quantitative RT PCR to assess their expression pattern in different tissues after varying degrees of drought in a rice cultivar Nagina22. Differential expression pattern collectively suggest annexin genes do not serve completely redundant function and have both distinct and overlapping function. Based on this transcript profiling annexin cDNAs were cloned and mobilized to Indian mustard. Here the characterization of this novel gene family in rice will be discussed. The information will

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be valuable for future studies needed to clarify the precise function of each individual annexin and to resolve which annexins have overlapping or distinct functions in calcium signaling under water stress.

P 4.06 - Proteomics and metabolomics analysis of stem reserves and mobilezation in wheat under drought stress Bazargani M.M.1,2, Sarhadi E.1, Mock H.P.3, Hajirezaei M.R.3, Bushehri A.A.S.2, Naghavi M.R.2, Ehdaie B.4 , Salekdeh G.H.1 (h_salekdeh@abrii.ac.ir) 1 Agricultural Biotechnology Research Institute of Iran, Karaj, Iran; 2 Faculty of Agriculture, Tehran university, Karaj, Iran; 3 Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany; 4 Department of Botany and Plant Science, University of California, Riverside, CA 92521-0124. Terminal drought is one of the major factors limiting the yield of wheat (Triticum aestivum L.). Under terminal drought condition, remobilization of pre-stored carbohydrates in wheat stem to grain has a major contribution in yield. To determine the mechanism of stem reserves and mobilization to drought tolerance, we investigated changes in stem proteome patterns and some metabolites during a progressive post-anthesis drought stress. Two genotypes of wheat (NO.49 and NO.14) differing in their stem reserve remobilization were cultivated in the greenhouse under well-water and drought conditions. Drought stress initiated just after anthesis and peduncle samples were collected from well-watered and drought-stressed plants 10, 20 and 30 days after stress initiation. Changes in peduncle dry weight, water soluble carbohydrates and enzyme (sucrose-sucrose fructosyl teransferase, invertase and fructokinase) during drought stress revealed that genotype No.49 was able to remobilize its stem reserves more efficiently. The temporal changes of total proteins in wheat peduncles were examined using two-dimensional electrophoresis. Out of 830 protein spots reproducibly detected on each gel, about 135 spots showed significant changes in the two genotypes under drought. 92 proteins showed genotype specific patterns of up- or down-regulation in response to drought in the different times after anthesis. Mass spectrometry (MALDI TOF/TOF and Q TOF) analysis of proteins resulted in identification of more than 100 proteins involved in several processes including carbohydrate metabolism and energy production, signal transduction, drought stress specific responses, and oxidative stress defense. Our results indicated some of these proteins could provide a physiological role in increasing of stem remobilization under drought which may confer drought tolerance. Some of the data of metabolomics analysis indicated integrity of proteomics and physiology data also.

P 4.07 - Introduction of Arabidopsis thaliana DREB1A/CBF3 transcription factor into soybean improves drought stress tolerance. Beneventi M.A.1, Nakashima K.2, Yamanaka N.2, Binneck E.3, Farias J.R.B.3, Oliveira M.C.N.3, Neumaier N.3, Abdelnoor R.3, Marcelino F.C.3, Marin S.R. R.3, Silveira C.A. 3, Fuganti R.3, Stolf R. 3, Salinet L.4, Rolla A.A.P.5, Polizel A.M.6, Yamaguchi-Shinozaki K.2, Nepomuceno A.L.3

(nepo@cnpso.embrapa.br)

1 UFRGS-Federal University of Rio Grande do Sul - Porto Alegre, RS, Brazil; 2 JIRCAS (Japan International Research Center for Agriculture Science), Tsukuba, Japan; 3 Embrapa Soybean, Caixa Postal 231, CEP 86001-970 Londrina, PR, Brazil; 4 Esalq- Piracicaba, SP, Brazil; 5 Londrina State University, Londrina, PR, Brazil; 6 Maringá State University, Maringá, PR, Brazil. Drought is one of the most serious abiotic stresses, resulting in substantial yield losses. Biotechnological tools provide the possibility to improve drought tolerance. Genetic engineering using the Arabidopsis thaliana transcription factor DREB1A/CBF3 controlled by the Arabidopsis stress-inducible promoter rd29A, has been shown to improve drought tolerance in several species. We introduced the constructs, rd29A:AtDREB1A and rd29A:GUS, to soybean, to determine if the strategy has potential to improve drought tolerance. Twenty positive

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lines were obtained by biobalistics transformation, and transgene stability of inheritance was confirmed. Histochemical analyses using plants containing rd29A:GUS confirmed induction of the rd29A promoter under dehydration conditions. Expression analyses showed that the DREB1 gene was up regulated in the transgenic soybean lines P58 and P1333 containing rd29A:AtDREB1A under dehydration conditions. The expression of GmPip1 encoding aquaporin and that of GmGolS2 encoding galactinol synthase in P58 was higher than that in the non-transformed isogenic BR16 line under dehydration conditions. Physiological and anatomical characterizations were also performed in P58 T2 generation plants. On average, physiological parameters, such as net photosynthesis and photosynthetic efficiency, were superior in P58, when compared to BR16. No significant anatomical differences were observed among transgenic or control soybean plants. These results showed that the combination of Arabidopsis DREB1A transcription factor protein and Arabidopsis rd29A promoter is useful to enhance tolerance against drought in soybean without growth deficiency.

P 4.08 - Integrated physiological approaches to evaluate wheat tolerance to water and high temperature stress Brestič M.1(Marian.Brestic@uniag.sk), Olšovská K.1, Živčák M.1, Repková J.1, Hauptvogel P.2, Gao H.Y.3, Yang X.H.3

1 Department of Plant Physiology, Slovak University of Agriculture, Tr. A. Hlinku 2, Nitra, 949 76, Slovakia; 2 Plant Production Research Center Piešťany, Bratislavská 122, 921 68 Piešťany, Slovak Republic;

3 Department of Plant Science, College of Life Science, Shandong Agricultural University, Taian, Shandong 271018, China.

Drought and high temperature limit the agricultural production in Slovakia (Central Europe) by preventing the crop plants from expressing their full genetic potential. Analysing physiological detrminants of yield responses to water may help in breeding for higher yield and stability under drought conditions. Breeding of high yielding varieties may be efficient for optimum to moderate stress conditions, however severe drought stress conditions demand for stress target selection traits that confer plant survival. In this work we focus on integrated methodology using physiological traits that contribute to improved plant productivity under mild to moderated drought and high temperature. Osmotic adjustment represents an important mechanism of plant stress responses to drough. The obtained data of tested ecologically distant wheat genotypes showed significant differences in capacity for accumulation of osmotically active compounds. The higher osmotic adjustment was correlated with delayed stomatal closure and this function can be considered as advantageous for reaching the higher photosynthetic assimilation in water limited growth conditions. There is a long-standing controversy as to whether drought limits photosynthetic CO2 assimilation through stomata closure or by metabolic impairment in C3 plants. In our experiments we compared photosynthetic reactions of drought tolerant wheat genotype Hanfeng 9703 (characterized also by high capacity for osmotic adjustment and high accumulation of glycinebetaine under drought) and drought sensitive genotype Shandong 921842. Gas exchange measurements of photosynthetic light response curves at high CO2 (2000 ppm) showed slightly higher CO2 assimilation rate in drought sensitive genotype Shandong 921842, however at normal (370 ppm) to low CO2 (100 ppm; physiological status analogous to sample with almost closed stomata) drought tolerant genotype Hanfeng 9703 obtained a significantly higher CO2 assimilation as well as A/Ci ratio (CO2 assimilation/ intercellular CO2 concentration). This indicates a higher carboxylation efficiency of this genotype. Delayed stomatal closure with higher values of net CO2 assimilation was possitively correlated with higher grain yield in drought conditions.

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P 4.09 - Perception and long-distance signalling of stress by plants in water scarce environments Davies B. (w.davies@lancaster.ac.uk) LEC, Lancaster University, Lancaster, LA1 4YQ, UK. Plants in water scarce environments have the capacity to detect both soil and atmospheric drought. Interactions between roots and drying soil generate both chemical and hydraulic signals which move through the plant to the shoot to regulate plant growth, development and functioning. For example, only small reductions in soil moisture availability can modify the pH of the xylem sap and the shoot apoplast, thereby affecting the partitioning of the hormone abscisic acid (ABA) in the leaf. Such changes will exert control on stomatal behaviour and plant water loss, and growth and development of plants may also be affected via this signalling mechanism. ABA-based control of these variables can be enhanced by alkalini- sation of the apoplast, even under circumstances where the delivery of ABA to shoots is not enhanced by soil drying. Apoplastic pH can also be modified by changes in evaporative demand such that variation in apoplastic pH will allow some integration of edaphic and climatic impacts on stomata. More severe soil drying will influence the delivery of a range of hormonal signals to the shoots and in this paper we show that as the soil dries, both the ethylene and the cytokinin balance of shoots can change to impact significantly on shoot functioning and development. This paper will also highlight ways in which a range of soil conditions (e.g. soil nutrient status and rhizoflora) can modify the plant’s capacity to detect soil drying and the way in which the plant functions in drying soil. Both genetic and agronomic techniques can be used to exploit plant signalling processes to enhance water use efficiency in agriculture.

P 4.10 - Tillering and water soluble carbohydrates accumulation in wheat: are they related? Dreccer M.F.1 ( fernanda.dreccer@csiro.au ), Rattey A.R.2, Chapman S.C.2, Herwaarden A.F.2, Shorter R.S. 2

1 CSIRO Plant Industry, Cooper Laboratory, Warrego Highway, Gatton, QLD 4343, Australia; 2 CSIRO Plant Industry, 306 Carmody Rd, St Lucia, QLD 4067, Australia. Wheat is cultivated worldwide, from low to high input agricultural systems. Key to the domestication and plasticity of wheat is the process of tillering and the ability to store water soluble carbohydrates (WSC) in the stem. Tillering is a degree of branching that determines canopy architecture, influences the grain number per unit area via the number of spikes per plant, and has a role in leaf area development and water use. The ability to store and remobilise WSC to grain constitutes a desirable trait to incorporate into germplasm targeted to regions with frequent terminal drought. We report a series of experiments using a small set of recombinant inbred lines contrasting in stem WSC and/or tillering. We found that the high WSC phenotype had consistently lower grain number m-2 linked to a lower number of spikes and stems m-2, higher individual grain weight, individual stems with less structural biomass and a moderate yield advantage when grown under stored moisture. The regulation of stem number per plant, mainly via tillering and to a certain extent tiller death occurs earlier during crop development relative to WSC accumulation. In the simplest scenario, higher WSC accumulation would be explained by partitioning available carbon among fewer stems, but there are indications that this may not be the only mechanism involved, since high WSC lines had a higher proportion of biomass invested in stems vs. leaves despite the lower stem number per plant. We conducted further studies to determine how or if the WSC concentration varies genetically with planting density, by growing the recombinant inbred lines from 50 to 400 pl m-2. We tested if (a) the genotypic ranking of tillering and WSC observed at current practice plant density is independent of plant population; (b) the differences in maximum tiller number per m-2 observed at anthesis can be connected to processes involved in tiller initiation or cessation. In this paper we propose a model of how tillering and WSC accumulation are linked and discuss to what extent they can be manipulated for better breeding outcomes.

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P 4.11 - Stress inducible expression of DREB factors increases drought tolerance of transgenic wheat and prevents undesirable changes in plant development Eini O. (omid.eini@acpfg.com.au), Morran S., Bazanova N., Pyvovarenko T., Shirley N., Sing R., Ismagul A., Eliby S., Langridge P., Lopato S.

Australian Centre for Plant Functional Genomics Pty Ltd, Hartley Grove, Urrbrae SA 5064, Australia. Transcription factors (TFs) have been shown to mediate stress signal transduction and response to different stresses in plants and therefore provide attractive targets for application in molecular plant breeding. In this study two drought inducible TFs from wheat grain, TaDREB2 and TaDREB3, were over-expressed in barley and wheat using a strong drought inducible promoter with the aim to increase drought tolerance without producing undesirable phenotypes. Transgenic plants with constitutive over-expression of TaDREB2 under double 35S promoter showed a delay in germination and flowering and stunted growth. TaDREB3 transgenic plants showed a similar, but even stronger phenotype. At flowering stage they were about 1/3 smaller than wild type plants and produced twice as many tillers. However, expression of DREB factors under the control of the stress inducible ZmRab17 promoter totally eliminated the undesirable phenotypes in wheat plants. Unfortunately, the same construct only slightly improved the situation in barley. The result can be explained by the high basal level of activity of this promoter in barley, whereas no basal activity was found in any of twelve independent transgenic wheat lines. Drought inducible expression of transgenes in transgenic wheat was 100-400 folds higher than drought inducible expression of endogeneous TaDREB2 and TaDREB3. Levels of transgene expression quickly went down after re-watering. Transgenic wheat plants (T1, T2 and T3) showed remarkable drought tolerance on the seedling stage of development. They demonstrated quick recovery from stress and started flowering three weeks after re-watering. Under similar stress condition no control plants survived. The level of drought tolerance was correlated with the strength of expression of transgenes and was stronger in plants with TaDREB3 overexpression.

P 4.12 - Effect of water stress on gluten proteins in durum wheat: a proteomic approach Flagella Z. (z.flagella@unifg.it), Pompa M., Palermo C., Giuliani M.M., Giuzio L., Mentana A., Centonze D. Dep. of Agro-Environmental Science, Chemistry and Crop Protection and Interdep. Research Centre BIOAGROMED, Foggia University, Via Napoli, 25-71100 Foggia, Italy. Proteomics has the potential to contribute to our understanding of grain quality by elucidating the way in which the genes are expressed under different environmental conditions. In particular grain filling is a critical growth stage in determining technological quality of durum wheat, involving the folding of storage proteins and their assembly by disulphide cross-links to form the gluten matrix of dough. The production of grain specifically suited to market requirements may be achieved both by using suitable genotypes and by optimizing growth conditions. In the framework of the project FAR-AGROGEN of the Italian Ministry of University, our research group aims at evaluating by a proteomic approach the effect of water stress applied during grain filling on gluten protein composition of durum wheat. To this purpose, two durum wheat cultivars characterized by a different technological quality, Ciccio and Svevo, were grown in a growth chamber under two water regimes (irrigated and non irrigated). Grain samples were collected at 13, 26 and 40 DPA; gluten proteins were then extracted and analyzed by 2D electrophoresis (IEF x SDS-PAGE), as reported in Ferrante et al. (2006). Protein spots were analyzed by ImageMaster 2D Platinum 6.0 software (Amersham), excised from gel and digested with chymotrypsin using a procedure modified by Rocchetti et al. (2008). Digested peptides were then analyzed by nano-HPLC- MS/MS. Spectra were evaluated by Data Analysis software (Bruker Daltonics). Protein identification was performed by searching the NCBI using MASCOT. Blast local alignment search tool (BLAST) was used to find regions of local similarity between sequences. Under water stress a higher expression in some glutenin spots was observed. Protein identification by mass analysis is in progress.

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P 4.13 - Advances on gene cloning and function on drought stress in wheat Fu Z.Y. (xianghongf2006@hotmail.com), Zhang Z.B. (zzb@sjziam.ac.cn), Hu X.J., Song W.Y. Center for Agricultural Resources Research, Institute of Genetic & Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China. Wheat is a main crop in the semiarid area, while its product is often severely decreased by water deficit stress. Usually the cloning and function identification of wheat gene is consi- dered to be difficult because wheat genome is very complicated. But in recent years with the development of molecular biology, CDNA-AFLP, map-based cloning, EST-based cloning, suppression subtractive hybridization (SSH) and yeast two-hybrid system have been used to isolate wheat gene. What is more, RNA interference, overexpression, antisense suppression have been used to identify wheat gene function. Up to now in wheat the genes related with drought stress mainly include Late-embryogensis-abundant protein (LEA protein), Anti- oxidative enzymes (POD, SOD, CAT), the bZIP transcription factors, MYC and MYB transcription factors, WRKY transcription factors and DREB/CBF transcription factors as well as some cis-responsive elements. In addition, we cloned two NADP-ME genes (TaNADP- ME1 and TaNADP-ME2) from wheat and they response to drought, salt and cold stresses in wheat leaves. It is worth mentioning that TaNADP-ME2 is light-responsive gene and may facilitate wheat high water use efficiency breeding aimed at improvement of wheat yield and drought-resistance. These researches offer many valuable information and solid base for functional genomics, proteomics, metabonomics, signal net of wheat gene, especially for the resistance of transgenic wheat plant to water deficit stress. This review mainly deciphers the advances on cloned wheat genes relating to drought stress and the relationship of them and drought stress.

P 4.14 - Physiological characteristics of overexpression phosphoenolpyruvate carboxylase (PEPCase) gene in rice under drought stress Guan D.M.1 (guandongming123@163.com; gdming@cumtb.edu.cn), Zhao M.2, Ding Z.S.2, Chen Y.1, Zheng S.Q. 1, Liu F.Z.1

1 College of Chemistry and Environmental Engineering, China University of Mining and Thechnology

(CUMTB), Beijing 100083, China; 2 Chinese Academy of Agricultural Sciences (CAAS), Beijing 100081, China. Pot experiments were conducted to study the effect of short-term drought on leaf water potential, photosynthesis and dry matter partitioning at four rice growth stages in overexpression phosphoenolpyruvate carboxylase gene rice (ZM03) and wild-type ZH8 as control group. Data suggest that net photosynthetic rate (Pn) decreased as the drought stress increased, however, PS maximum Ⅱphotochemical efficiency (Fv/Fm) kept stable. PS actual photochemical efficiency (ФPS ) and photochemical Ⅱ Ⅱquenching (qP) declined, the decrease was less in ZM03 than in ZH8. Under drought stress, the activities of two antioxidant enzymes (SOD, POD) increased, but the increase in ZM03 was more than in ZH8.Moreover, under severity drought stress, pigment contents, gas exchange and fluorescence parameters became worse and worse in both materials, the activities of two antioxidant enzymes (SOD, POD) decreased initially, and then increased. The content of Chla and Chlb both increased，and the increase in ZM03 was more than in ZH8，too. The results showed that drought resistance of transgenic rice is higher than wild-type rice under severe drought stress.

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P 4.15 - Morphological and physiological characterisation of wild wheat relative Aegilops species Hauptvogel P. (hauptvogel@vurv.sk)1, Brestič M.2, Olšovská K.2, Živčák M.2, Repková J.2

1 Plant Production Research Center Piešťany, Bratislavská 122, 921 68 Piešťany, Slovak Republic; 2Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic. The genus Aegilops is a genus of plants generally known as goatgrasses and belonging to the grass family Poaceae. There are about 23 species and numerous sub species in the genus, which are classed as agricultural weeds and some of them can be crossed with the various types of cultivated wheat. Species in the genus Aegilops are distributed in the Southwest and Central Asia, throughout the Mediterranean basin and South Europe. The frame scientific project financed by the Slovak Research and Development Agency was organising the collecting missions from Slovakia, Hungary, Czech Republic, Slovenia, Bulgaria and Armenia. Collaborative missions between the Research Institute of Plant Production Piešťany, Slovak Republic and Plant Genetic Resources Laboratory of the Armenian State Agrarian University Yerevan and Scientific Center of Agrobiotechnology of the Ministry of Agriculture, Armenia, were undertaken to exploration and collecting accessions of the genus Aegilops. An increasing interest in the study and use of wild wheat relatives of wheat has led to considerable collecting of such genetic material. Morphological diversity was analysed using a set of fourteen quantitative traits. The objectives of this investigation were to evaluate drought tolerance of wild wheat relatives and identify quantitative attributes that can be used to evaluate Aegilops germplasm potential for breeding purposes. The results show applicability at least of 2 photosynthetic parameters (performace index, PI and maximal photochemical PSII efficiency, Fv/Fm), which enable to distinguish Aegilops species according to their performance of photosynthetic apparatus under stressful environmental conditions.

P 4.16 - Exogenous glycinebetaine and proline modulate antioxidant defense and methylglyoxal detoxification systems and reduce drought-induced damage in mung bean seedlings (Vigna radiata L.) Hossain M.A., Fujita M. (fujita@ag.kagawa-u.ac.jp) Department of Applied Biological Science, Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa 761-0795, Japan. The physiological aspects of plant responses to water deficits are well known. The challenge is to find the biochemical aspects and molecular pathways that set in motion this response as well as the deciding factors that determine their relative sensitivities. In this study, the content of ascorbate (AsA), glutathione (GSH), H2O2 and the activities of their associated enzymes involved in antioxidant defense and glyoxalase systems were investigated to assess the protection offered by proline and glycinebetaine in mung bean seedlings subjected to in vitro drought stress of -0.5 and -2.0 MPa for 24 h induced by polyethylene glycol (PEG). Drought stress caused a significant increase in H2O2 content but a decline in AsA content. GSH contents increased significantly due to mild drought stress; however, a sharp decrease was found under severe drought stress. The activities of glyoxalase I (Gly I, EC 4.4.1.5), glyoxalase II (Gly II, EC 3.1.2.6), glutathione S-transferase (GST, EC 2.5.1.18), glutathione peroxidase (GPX, EC 1.11.1.9), and ascorbate peroxidase (APX, EC 1.11.1.11) showed consistent increases with increasing levels of drought stress, however, catalase (CAT, EC 1.11.1.6) activity declined. Mild drought-stressed plants had higher glutathione reductase (GR, EC1.6.4.2) and dehydroascorbate reductase (DHAR, EC 1.8.5.1) activities than the control plants but the activity declined at higher levels of drought stress. Proline or glycinebetaine pre-treated drought-stressed seedlings resulted in an increase in AsA and GSH content, maintenance of higher activities of Gly I, Gly II, GST, GPX, GR, APX, DHAR and CAT involved in the reactive oxygen species (ROS) and methylglyoxal (MG) detoxification systems even under high levels of drought stress compared to those of the control as well as those in most cases seedlings subjected drought stress without pre-treatments, with a simultaneous decrease in H2O2 content. The present study, therefore, suggests that both proline and glycinebetaine provide a protective action against drought-induced oxidative damage by reducing H2O2 levels and by enhancing antioxidant defense and MG detoxification systems, however, betaine is more effective than proline.

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P 4.17 - The influence of cuticular wax loads on wheat drought resistance and infertility Hu X.J.1,2, Zhang Z.B.1 (zzb@sjziam.ac.cn), Fu Z.Y. 1,2, Xu P.1, Xu Q.Q. 1

1 Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, CAS, Shijiazhuang 050021, China;

2 Graduate University of the Chinese Academy of Sciences, Beijing 100049, China. In this paper, three pairs of sister-in-line with different wax content under field conditions were treated with twice irrigation, once irrigation and no irrigation, respectively. To provide useful information of wheat drought tolerance breeding, correlation relationship between wax content and multiplex physiological index of drought tolerance were investigated. The results are as following. Wax content of glaucousness is higher than that of non- glaucousness sister-in-line in different development phase under different water treatments. Correlation index of wax content in Max. numeber of florets and pollination phase is 0.834, which is significat at 0.01 level. We can conclude that glaucousness and non-glaucousness can represent wax content and be regard as wheat wax breeding phenotype characters. In in Max. numeber of florets and pollination phase, three pairs of sister-in-line present the following common change current, along of drought aggravation, wax content is increasing, and leaf water use efficiency is increasing along of wax content (0.412**, 0.279*), meanwhlile, transpiration rate (-0.369**, -0.299**) and intercellular CO2 concentration (-0.281*, -0.615**) are decreasing. In addition, wax content has great influence on wheat infertility. Along of wax content increasing, amount (-0.458**, -0.360*) and percentage (-0.457**,-0.364**) of sterility spikelet are decreasing, and seed of one spike (0.456**, 0.386**) is increasing.

P 4.18 - Abscisic acid mediated polyamines metabolism enhances hydrogen peroxide production and stomatal closure in vitis vinifera Imene T.1,2 (toumine@yahoo.fr), Nikolaos M.P.2, Konstantinos P.2, Mliki A.1, Ghorbel A.1, Roubelakis-Angelakis K.2 1 Labratory of Grapevine Molecular Physiology, University of Tunis II, Tunisia; 2 Department of Biology, University of Crete, P.O. Box 2280, 71 409 Heraklion Crete, Greece. ABA is a major signal in plant response to environmental stresses. Under osmotic stress, the signaling pathway induced via ABA, involves several secondary metabolisms including polyamines (PAs). Although PAs were demonstrated to be ABA-inducible, little data are available concerning the mechanisms involving ABA-PAs in osmotic stress response in Vitis vinifera. Leaf discs obtained from two contrasting vine cultivars ‘Kahli Kerkennah’, as tolerant, and “Guelb sardouk’ as sensitive, were placed in MES medium supplemented with mannitol (200 mM) and ABA (10 µM), separately. Leaf discs treated with mannitol and ABA exhibited soluble PAs (putrescine and spermine) accumulation, differently in the two genotypes. In the tolerant genotype, putrescine catabolism was enhanced by mannitol and ABA treatments via the activation of both arginine decarboxylase (ADC) and ornithine decarboxylase (ODC), and spermine was induced via the increasing SAMDC activity. In opposite, the anabolic activity was much less responsive to both treatments in the sensitive genotype. A noticeable increase of the anabolic DAO and PAO activities was detected in both genotypes. ABA, mannitol, as well as PAs (Put, Spd, Spm) supplemented separately to leaves enhanced as well stomatal closure, correlated to H2O2 production. The amounts of H2O2 were higher in the sensitive genotype than the tolerant. These results suggest that ABA mediated polyamine induction and oxidation, especially spermidine, is a key factor for H2O2 generation, which is involved in stomatal closure. In conclusion, polyamines are shown to be induced under osmotic stress through the ABA signaling pathway in Vitis vinifera and they play a crucial role in stress response and adaptation, through the production of H2O2 involved in stomatal closure, main factor for water saving under drought conditions.

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P 4.19 - Physiological responses to drought stress in cutleaf medic (Medicago laciniata (L.) Mill) Javid M.G.1 (majidivaj@yahoo.com), Akbari G.A.2, Moradi F.3, Sorooshzadeh A.1, Sanavi A.M.M.1, Allahdadi I.2

1 Department of Agronomy, Agriculture Faculty, Tarbiat Modares University, Tehran, Iran; 2 Department of Agronomy and Plant Breeding, Abooreihan Campus, University of Tehran, Pakdasht,

Tehran, Iran; 3 Agricultural Biotechnology Research Institute of Iran, Seed & Plant Improvement Campus, Karaj, Iran. Cutleaf medic (Medicago laciniata(L.) Mill) is a species of fabaceae family which a drought tolerant genotype of cutleaf medic was recognized from Iran arid areas (rainfall 170-190 mm y-1). In order to study of physiological responses to drought stress in sensitive and tolerant genotype of cutleaf medic, a greenhouse experiment was conducted at the Agricultural Biotechnology Research Institute of Iran, using a factorial arrangement in RCBD with three replications. Two genotypes of cutleaf medic, sensitive and tolerant to drought stress was treated in four levels of water stress include -0.1, -0.2, -1 MPa as low, medium and high stress levels respectively and normal condition (FC = -0.03 MPa). Physiological Charac-teristics were measured in first day to reach per stress level and ten days after to remain in stress levels. Results indicated that tolerant genotype had a significant superiority to sensitive genotype in most studied characteristics such as, RWC, WP, OA and organic solutes including Proline, Total sugar and inorganic solutes among K+, Ca2+. RWC and water potential were decreased in both genotypes, but in sensitive genotype was more than another genotype. In tolerant genotype was decreased osmotic potential to cause osmolytes accumulation. Inorganic solutes as potassium and organic solutes as soluble sugar were caused for osmotic potential decrease and osmotic adjustment mechanism. This experiment indicated that osmotic adjustment is one of the major concerns of tolerance. Therefore it might be possible to use physiological responses for selection of drought tolerant medics or gene transfers them.

P 4.20 - Chemical signalling and stomatal conductance in pot-grown strawberry under different irrigation regimes Jensen N.L.1,2(NaujaLisa.Jensen@ agrsci.dk), Jensen C.R.2, Liu F.L.2, Petersen K.K.1 1 Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen, Hoejbak- kegaard Allé 13, DK-2630 Taastrup, Denmark;

2 Department of Horticulture, Faculty of Agricultural Sciences, University of Aarhus, Kirstinebjergvej 10, DK-5792 Aarslev, Denmark.

The effect of partial root-zone drying (PRD), as compared to full irrigation (FI), deficit irrigation (DI), and non-irrigation (NI) on soil and plant water relations, leaf stomatal conductance (gs) and abscisic acid concentration in the xylem sap ([ABA]xylem) of strawberry [Fragaria xananassa (Duchesne) ‘Honeoye’] plants were investigated in a split-pot green- house experiment. In the FI treatment the whole root zone was irrigated daily to pot holding capacity while the DI and PRD treatments were irrigated with 70% of the volume of the FI to either the whole or one half of the root system, respectively. In PRD, irrigation was shifted from one side to the other side of the plants when the soil water content (θ) of the dry side had decreased to ca. 10%. These irrigation regimes resulted in a significant reduction in θ of the DI and PRD as compared to FI. However, there were only observed significant differences in crown water potential (ψcrown), leaf water potential (ψleaf) and gs at a few occasions between the irrigation treatments at the end of the experimental period. The [ABA]xylem was significantly increased by the NI treatment but not significantly effected by the DI and PRD treatments as compared with the FI treatment. The increase in [ABA]xylem of NI plants coincided with marked decreases in ψcrown, ψleaf and gs three to four days after withholding irrigation. [ABA]xylem was linearly correlated with ψcrown when ψcrown dropped below a critical value of -0.4 MPa. The gs tended to decrease as a function of [ABA]xylem, but it was also highly related to the water vapour pressure deficit (VPD) of the air.

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P 4.21 - Gene-expression profiling of two alfalfa genotypes with contrasting drought sensitivity Kang Y. (ykang@noble.org), Torres-Jerez I., Zhang J.Y., Wang M.Y., Wang Z.Y., Zhao P., Tang Y.H., Monteros M., Udvardi M. The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA. Alfalfa is one of the most important forage crops in the US and throughout the world. Compared with other common crops, alfalfa is relatively drought-tolerant. However, water is still a major limiting factor for its distribution and productivity. One important goal of alfalfa breeding is to improve drought tolerance while retaining high yield. To accomplish this goal, understanding the mechanisms of alfalfa’s response to drought stress as well as developing more efficient breeding strategies for this perennial autotetraploid crop are essential. In the current project, a diverse collection of alfalfa genotypes were evaluated and one drought- sensitive genotype – “Chilean” (M. sativa ssp. sativa var. Chilean), and one drought-tolerant genotype–“Wisfal” (M. sativa ssp. falcata var. Wisfal), were selected and compared. Affymetrix GeneChip analysis was performed on these two genotypes subjected to mild, moderate, and severe water-deficiency, and to a recovery phase. Candidate drought- responsive genes and gene networks that may confer drought tolerance in alfalfa were identified. Comparisons were made between the gene-expression data and physiological characteristics of these two alfalfa genotypes, with a view to understanding better the inter- play between the different levels of response.

P 4.22 - New tools for photosynthesis and yield enhancement in wheat under drought stress Kershanskaya O.I. (gen_o.kersh@mail.ru)

Institute Plant Biology and Biotechnology, National Center Biotechnology RK; 45 Timiryazev str., Almaty 050040, Kazakhstan. The first limiting factor of crop yield in Central Asia is water deficit and agriculture can be practiced only with additional irrigation. Increasing the adaptation potential of major crop and creating drought-tolerant genotypes with genetically determined adaptation of photosynthetic apparatus to drought is one of the biggest scientific and economic issues for this region and world-wide. C4 photosynthesis can greatly enhance crop productivity over C3 photosynthesis, yet most crops directly consumed by people (for example, rice, wheat and cotton) are C3 species, that means they are not properly adopted to modern climate change, especially to drought and desertification. Radical improvements in crop productivity, such as engineering C4 photosynthesis into C3 plants, are necessary to ensure continued food security thus drought resistance. The ultimate objective of our research is to investigate the advances in transfor- mation technologies and thus establish approaches for genetic modification of photosynthesis in wheat for increase grain yield under abiotic stress, including water limited conditions, through introduction of maize genes encoding the C4 photosynthesis enzymes into wheat. Simple natural germ-line method of transformation by Pipetting Agrobacterium into the spikelets of wheat before anthesis has being elaborated. Method used wheat indirect pollen system contains high quantities of flavonol glycosides which acts as inducers of vir region of the Ti plasmid. Using this method have been produced about 5000 transgenic wheat seeds of 30 genotypes, and have been created number of transgenic wheat plants of T1 – T3 generations. High level of the maize C4-specific PEPC gene expression that has being introduced into transgenic wheat plants was determined by assaying the activity of PEPC in leaf protein extract, followed by CO2 gas-exchange and photorespiration measurements, leaf anatomy investigation, yield structure, PCR, Real-time PCR, Southern blot analyses. Stable wheat transformation in T2 has been confirmed by molecular biological techniques and high grain yield increasing up to 25%-50% in transgenic plants in comparison with wild types, especially at adverse conditions. The effects of drought on the photosynthetic apparatus have been studied in transgenic wheat plants expressing maize PEPC enzyme. For the study of drought effects, photosynthetic performance in PEPC transgenes was found to be a very informative indicator, because of its extreme resistance to environmental stresses. Using of transgenic C4 wheat as the model for research of metabolomics, functional genomics, phenomics under water limited conditions is discussed.

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P 4.23 - Alterations in the activities of antioxidant enzymes in Triticum aesti- vum under water stress conditions Khan N. (tabnadus@yahoo.com, naqvi.farzana@gmail.com), Naqvi F.N. Department of Genetics, University of Karachi, Karachi 75270, Pakistan. Current research was conducted with the objective of observing changes in the activities of antioxidant enzymes and MDA content which may play a part in distinguishing tolerant and susceptible genotypes. The experimental material consisted of germplasm of 13 wheat genotypes including 11 bread wheat advanced lines from different sources, 1 synthetic hexaploid and its durum parent. The experiment was conducted using earthen/ceramic pots (40 cm×40 cm); stress was imposed by withholding irrigation at three different growth stages of plant i.e. tillering, anthesis and grain filling. Experiment was carried out in a randomized complete block in a split-plot arrangement. Water regimes (irrigated and non-irrigated) were allocated to the main plots and genotypes to the sub-plots. Second leaves/flag leaves were collected after 15 days of stress at respective treatments (non- irrigated) along with control samples (irrigated). The activity of peroxidase and catalase were estimated. Lipid peroxidation was measured as Malondialdehyde content. Variable response of genotypes has been observed at different water regimes. Water stress treatments had no significant effect on catalase activity. Genotypes CIM-47, CIM-49 and NR-234 showed minimum MDA content with increased peroxidase activity under three irrigation levels and are therefore considered as tolerant genotypes. Higher levels of MDA with decline in peroxidase activity in CIM-51, DD-4 and NR-230 led to suggest them as susceptible genotypes. The variable response of genotypes in tolerance could be related to differences in antioxidant enzyme levels. The information obtained from present studies could be use for selecting genotypes that are stress tolerant or susceptible.

P 4.24 - Transgenic crops with enhanced tolerance to multiple environmental stresses on marginal lands Kim Y.H.1, Wang W.B.2, Deng X.P.2, Ma D.F.3, Mok I.G.1, Lee H.S.1, Kwak S.S.1(sskwak@kribb.re.kr) 1 Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotech-

nology (KRIBB), 111 Gwahangno, Yuseong-gu, Daejeon 305-806, Korea; 2 Institute of Soil and Water Conservation, CAS, Yangling, Shannxi 712100, China; 3 Institute of Sweet potato, Chinese Academy of Agricultural Sciences, Xuzhou, Jiangsu 221121, China. To cope with global crises over food and energy supplies as well as environmental problems, it is urgently required to develop new crop varieties to be grown on marginal lands including desertification areas for sustainable agriculture. In this respect, to generate transgenic crops such as potato (Solanum tuberosum L), sweetpotato (Ipomoea batatas) and alfalfa (Medicago sativa L.) plants with enhanced tolerance to environmental stress, multiple stress-tolerant genes were introduced into plant genome under the control of an oxidative stress-inducible SWPA2 promoter. Transgenic potato (cv. Superior) plants with the ability to synthesize glycinebetaine (GB) in chloroplasts by introduction of the bacterial choline oxidase (codA) gene (referred to as SC potato plants) were characterized. The GB contents in the leaves of SC potato plants following methyl viologen (MV) treatment were found to be 1.43 mmol/g fr wt by HPLC analysis. In addition to reduced membrane damage after MV-mediated oxidative stress, the SC plants showed enhanced tolerance to NaCl and drought stress on the whole plant level. Transgenic plants (potato, sweetpotato and alfalfa) expressing Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) gene under the control of SWPA2 promoter (SN plants) were generated. SN plants showed enhanced tolerance to multiple stresses including drought, high salt and extreme temperature. In addition, the strategies for the development of industrial transgenic crops to combat desertification in China will be introduced in terms of global collaboration.

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P 4.25 - Comparative transcriptome analysis in roots of drought resistant and drought susceptible wild emmer wheat genotypes, in response to drought stress Krugman T.1 (krugman@research.haifa.ac.il), Chagué V.2, Peleg Z.3*, Just J.2, Korol A.B.1, Nevo E.1, Saranga Y.3, Chalhoub B.2, Fahima T.1

1 Department of Evolutionary and Environmental Biology, Institute of Evolution, Faculty of Science and Science Education, University of Haifa, Mt. Carmel, Haifa 31905, Israel;

2 Unité de Recherche en Génomique Végétale (URGV), Organisation and Evolution of Plant Genomes, 91057 Evry, France ;

3 The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel;

*present address: Department of Plant Sciences, University of California, Davis, Davis, CA 95616, USA.

Wild emmer wheat, Triticum turgidum ssp. dicoccoides (körn.) Thell, is the allo-tetraploid (2n=4x=28; genome BBAA) progenitor of domesticated wheats. Wild emmer wheat genepool has been found to harbor wide genetic diversity for various agronomically important traits. Wide phenotypic diversity in response to drought stress was reported in wild emmer for productivity (grain yield, spike dry matter, total dry matter and harvest index) and drought related morpho-physiological traits (water use efficiency, osmotic potential, chlorophyll content, plant height and heading date). These studies demonstrate that wild emmer offers rich allelic repertoire essential to improve drought resistance in domesticated wheat. The current study was aimed to identify genes expressed in roots in response to drought stress, which may be associated with drought resistance in wild emmer wheat. Two wild emmer wheat genotypes contrasting in drought resistance were analysed by transcriptome analysis (Affymetrix®) in response to drought stress. Analysis of variance (ANOVA) was used to test the effect of irrigation treatments (drought stress vs. well-watered control), genotypes (drought resistant vs. drought susceptible) and their interactions on gene expression patterns. Of the 61,127 probe-sets printed on the wheat genome array 4,969 transcripts were differentially expressed among genotype and/or treatment variables. Of them, 3,570 transcripts were affected by drought stress: 1,422 transcripts showed common regulation pattern in both genotypes, 3,152 transcripts were differentially expressed in the R genotype and 1,840 in the S genotype. The current study was focused on analysis of 196 differentially expressed transcripts showing three significant effects: genotype (G), stress (E) and G × E interaction. Of them, 33 transcripts were commonly expressed, 118 transcripts were differentially expressed in the R genotype whereas only 45 transcripts were differentially expressed in the S genotype. Annotation analysis of the putative gene products of the differentially expressed transcripts in the resistant genotype revealed that they are involved in multilevel regulation mechanisms, including transcription regulation (MYB, MADS-box), calcium signalling (centrin and calcium binding protein), and hormone signalling pathways (ABA, auxin, giberlin and cytokinin). A large group of membrane structural proteins were identified as involved in compound transport (lipid, carbohydrate and peptide transporters) and ion transport. These results suggest that some of the identified proteins are involved in adaptation to drought stress and demonstrate that the genepool of wild emmer wheat for improvement of drought resistance in cultivated wheat.

P 4.26 - The regulation of MITE on the sHSP expression in wheat Li J.T., Peng H.R., Sun Q.X., Liu Z.Y. (zhiyongliu@cau.edu.cn) Dept. of Plant Genetics & Breeding, China Agricultural University, Beijing 100193, China. Miniature inverted-repeat transposable elements (MITE) are frequently encountered in plant genomes and are often associated with gene rich regions, though little are known about their function in gene regulation. Small heat-shock proteins (sHSPs) with a monomeric molecular mass of 15~42 KDa are synthesized by all organisms in response to high temperature. Plant sHSPs are also produced under other stress conditions and at certain developmental stages, indicating they may play an important role in stress tolerance. We found a 276 bp tourist-like MITE insertion on the 3’ UTR of a 16.9 KDa sHSP on chromosome 3A.Haplotypic analysis revealed two haplotypes (with and

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without MITE insertion) were available in wheat germplasm.The insertion of MITE in the 3’ UTR of a 16.9 KDa sHSP provides an opportunity to study the effect of MITE insertion on gene expression in wheat. RT-PCR and Real-time PCR all revealed an increased transcript level of 16.9 KDa sHSP in wheat line (TAM107) containing MITE insertion compared with the wheat line (Chinese Spring) without MITE insertion after two hours heat-treatment at 40 ℃. In addition to heat stress, similar increased transcript level was evident for the sHSP gene with MITE insertion at low temperature treatment (0 ℃). It appeared likely that the MITE insertion into the 3’ UTR could enhance gene transcription. We are making 16.9 KDa sHSP constructs containing two different 3’ UTR cassettes (with and without MITE) and transforming Arabidopsis wild-type and mutants to characterize the function of MITE on gene expression regulation.

P 4.27 - Isolation and functional analysis of TaPP2Abβ from wheat (Triti-cum aestivum L.) Liu S.H.1, 2, Mao X.G.1, Liu H.M.2, Jing R.L.1 (jingrl@caas.net.cn) 1 The National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop

Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; 2 College of Bioengineering, Shanxi University, Taiyuan, Shanxi 030006, China. Wheat (Triticum aestivum L.) is one of the most important alimentary crops in the world, but frequently suffers drought stress during growing season. Improving drought tolerance of wheat cultivar is one of the efficient approaches for stabilizing the wheat production. A number of genes are involved in the drought tolerance. PP2A, a multi-subunit serine/threonine phosphatase gene involved in drought response, participates in a series of cell activities, such as cell differentiation and apoptosis, dephosphorylation on multiple substrates, signal trans- duction. PP2A holoenzyme consists of a constant dimeric core, a catalytic subunit (PP2Ac) and a structural subunit (PP2Aa) associated with one member of the variable regulatory subunit (PP2Ab) family. We have cloned and characterized TaPP2Ac and TaPP2Aa from wheat. Transgenic tobacco and Arabidopsis plants over-expressing TaPP2Ac and TaPP2Aa exhibited more tolerant to abiotic stresses, including drought, salt, mannitol and other osmotic stresses, than wild types. Based on the EST sequences identified from the cDNA library which responded to drought-stress from wheat seedlings constructed by our group, from which the original ESTs of TaPP2Ac and TaPP2Aa were screen out, we cloned one regulatory subunit gene of wheat PP2A. The subunit was designated as TaPP2Abβ-1, which contains 513 amino acids, a molecular mass of 35.503 kDa and pI value of 5.87. Alignment and phylogenetic analysis indicated that TaPP2Abβ-1 has 86% similarity to counterpart of rice (NP_001046333). The expression of TaPP2Abβ-1 was up-regulated by PEG, NaCl and ABA treatments, suggesting it may play an important role in responding to abiotic stresses. Transgenic Arabidopsis plants over-expressing TaPP2Abβ-1 have been gained. Phenotype evaluation of the transgenic plants is under way. Interactions of TaPP2Abβ-1 with TaPP2Aa and TaPP2Ac will be investigated in the near future.

P 4.28 - TaSnRK2.4, a SNF1-type serine-threonine protein kinase of wheat (Triticum aestivum L.) confers enhanced multi-stress tolerance in Arabidopsis Mao X.G., Zhang H.Y., Tian S.J., Chang X.P., Jing R.L. (jingrl@caas.net.cn)

The National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Osmotic stresses like drought, salinity and cold are major environmental factors that limit agricultural productivity worldwide. Protein phosphorylation/dephosphorylation are major signaling events induced by osmotic stress in higher plants. Sucrose nonfermenting 1-related protein kinase 2 family members play essential roles in response to hyperosmotic stresses in Arabidopsis, rice and maize. We cloned SnRK2.4 from common wheat, which is designated as TaSnRK 2.4, and characterized the function of TaSnRK2.4 in drought, salt and freezing stresses in Arabidopsis. Translational fusion protein of TaSnRK2.4 with green fluorescent protein showed subcellular localization in the cell membranes, cytoplasm and nucleus. To examine the role of TaSnRK2.4 under various environmental stresses, we generated transgenic Arabi- dopsis plants over-expressing TaSnRK2.4 under control of the CaMV-35S promoter. Transgenic Arabidopsis overexpressing TaSnRK2.4 exhibited slower seedling

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establishment, longer primary root and higher yield than wild type under normal growth condition, stronger tolerance to drought, salt and freezing stresses, which were simultaneously supported by the physiological results, including decreased water loss rate, enhanced higher relative water content, strengthened cell membrane stability, improved photosynthesis potential and significantly increased osmotic potential as well. Our results show that TaSnRK2.4 is involved in the regulation of osmotic potential enhancement, growth and development under both normal and adverse stress conditions, and implies that TaSnRK2.4 is a multifunctional regulatory factor in Arabidopsis. Since the overexpression of TaSnRK2.4 can significantly strengthen the tolerance to drought, salt and freezing stresses and does not retard the growth of transgenic Arabidopsis under well-watered conditions, TaSnRK2.4 can be utilized in transgenic breeding to improve abiotic stresses in crops.

P 4.29 - Cytokinin regulation of physiological and proteomic responses of a perennial grass to drought stress through gene transformation Merewitz E., Gianfagna T., Zhang Y., Huang B.R. (huang@aesop.rutgers.edu) Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ 08901, USA. Drought may cause leaf senescence, reducing plant growth. Leaf senescence is a dynamic process in perennial grass species, which is attenuated by drought stress. Cytokinins have known to play critical role in regulating leaf senescence, but how endogenous changes in cytokinin production may regulated drought tolerance through the effects on leaf senescence is not well understood, particularly in perennial grass species. Creeping bentgrass (Agrostis stolonifera L.) is an economically important cool-season C3 grass species that is widely used as a turfgrass but has limited drought tolerance characteristics. We have developed creeping bentgrass transgenic lines for an isopentyltransferase (ipt) transgene that increases endoge- nous cytokinin content, controlled by a senescence activated promoter (PSag12). These transgenic plants have allowed us to analyze both the effects of drought on endogenous cytokinin content and the effects of elevated cytokinin content on drought tolerance in attempts to understand cytokinin regulation of numerous stress tolerance mechanisms within perennial grass species. The current research focused on differential changes in cytokinin production antioxidant enzyme and proteomic responses to drought stress between the ipt transgenic bentgrass and the wild type while highlighting other physiological responses of the ipt plants, such as leaf cell membrane stability, water content, photochemical efficiency, chlorophyll content and root growth and viability. Plant hormone content was measured by enzyme–linked immunosorbent assays. Antioxidant enzyme changes under drought stress in both plant types were measured by biochemical activity assays. Differential protein expression between the transgenic and non- transgenic plant lines were analyzed by two- dimensional gel electrophoresis and mass spectrometry. Young leaves did not exhibit much significant difference in non-transgenic compared to ipt transgenic lines, however, older leaves showed a much greater difference in response to drought between the plant lines. Northern analysis and RT-PCR showed that the transgene was upregulated by increasing levels of drought stress. Transgenic lines were able to maintain significantly higher chlorophyll content, photochemical efficiency, relative water content, osmotic adjustment, and hormone content (primarily iPa) in older leaves longer than the wild type during drought stress. Our results demonstrate that ipt transgenic plants exhibited a slower decline in cytokinin content compared to non-transgenic lines during drought stress, maintained higher levels of antioxidant enzymes under stress conditions, and exhibited several other protein changes in various functional categories. Specific protein changes in response to the transgene and to drought stress will be discussed.

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P 4.30 - Evaluation of the stress-inducible production of proline in transgenic sugarcane (Saccharum spp.): osmotic adjustment, chlorophyll fluorescence and oxidative stress Molinari H.B.C.1 (hugo.molinari@embrapa.br), Marur C.J.1, Daros E.2, Campos M.K.F.1, Carvalho J.F.R.P. 1, Bespalhok J.C.F.2, Pereira L.F.P.3, Vieira L.G.E. 1

1 Embrapa Agroenergy – (CNPAE), CEP 70770-901, Brasilia DF, Brazil; 2 Department of Agronomy and Plant Protection, Federal University of Parana (UFPR), CEP 80035-050,

Curitiba PR, Brazil; 3 Embrapa Café, CP 481, CEP 86001-970, Londrina PR, Brazil. Proline accumulates in a variety of plant species in response to stresses such as drought, salinity and extreme temperatures. Although its role in plant osmotolerance remains controversial, proline is thought to contribute to osmotic adjustment, detoxification of reactive oxygen species and protection of membrane integrity. In the present study we evaluated the effects of stress-inducible proline production on osmotic adjustment, chlorophyll fluorescence and oxidative stress protection in transgenic sugarcane transformed with a heterologous P5CS gene. In well-watered conditions, free proline, malondialdehyde levels, Fv/Fm ratios and chlorophyll contents in transgenic sugarcane were not statistically different from non -transformed control plants. After 9 days without irrigation, proline content in transgenic events were on the average 2.5-fold higher than in controls. However, no osmotic adjustment was observed in plants overproducing proline during the water deficit period. The photochemical efficiency of PS II observed was higher (65%) in the transgenic events at the end of the water deficit experiment. The effects of proline on lipid peroxidation as malondialdehyde (MDA) levels and on the decline of chlorophyll content in paraquat-treated leaf segments along the drought period suggest that proline protected the plants against the oxidative stress caused by the water deficit. The overall capacity of transgenic plants to tolerate water deficit stress could be assessed by the significantly higher biomass yields 12 days after withholding water. These studies suggest that stress-inducible proline accumulation in transgenic sugarcane plants under water deficit stress acts as a component of antioxidative defense system rather than as an osmotic adjustment mediator.

P 4.31 - Drought stress and photosynthesis in flag leaves of rice (Oryza sativa ) Mushtaq R.1, 2, 3 (rohikhan400@gmail.com), Dar N.A.3, Katiyar S.2, Bennett J.1 1 International Rice Research Institute, Los Banos, Laguna, Metro Manila, Philippines; 2 Indira Gandhi Agricultural University, Krishaknagar, Raipur, India; 3 Sher-e-Kashmir University of Agricultural Sciences and Technology, Shalimar, Kashmir. Due to changes in global climate, crops are frequently getting exposed to several abiotic/biotic stresses. Thereby, affecting food supply and security. Among the abiotic stresses, drought has emerged as the major cause of rice yield instabilities across diverse crop-growing regions of Asia. Therefore, need of the hour is to develop drought tolerant rice genotypes. The worldwide water shortage and uneven distribution of rainfall makes the improvement of drought resistance especially important. Drought stress is one of the most important environmental factors inhibiting photosynthesis. In present study, Proteomic analysis on rapidly stressed flag leaves was conducted to identify proteins of different categories whose behaviour was adversely affected due to decline in the Relative water content (RWC) of flag leaves below threshold level. Here, we report about the proteins whose behaviour was affected under drought stress conditions in flag leaves of rice and were involved in photosynthetic process. Among the selected set of proteins, MALDI-TOF analysis identified five proteins involved in photosynthetic process. These proteins are: Rubisco Activase (RCA), Malate Dehydrogenase NADP chloroplast precursor (NADP-MDH) Ferredoxin Oxidoreductase (FNR), ATP-Synthetase and Thioredoxin-m. Out of these five proteins, three proteins viz., RCA, NADP-MDH and Trx-m, were found to be down regulated significantly in response to drought stress conditions. After one day of re-watering, these three protein spots were found to be reversible in their expression.

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P 4.32 - Overexpression of ICE1 gene in transgenic tobacco delays ethylene-induced senescence and imparts stress tolerance Nagaveni B.H., Jeyaraman R ., Rama N., Nataraja K.N. (nataraja_karaba@yahoo.com) Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore 560065, India. Plants, in both natural and agricultural conditions are frequently exposed to environmental (abiotic) stresses. Yield losses induced by abiotic stresses are estimated to reach 60%-70% due to fast changing climate. The knowledge of plant adaptive mechanisms is important for crop improvement towards stress tolerance. Studies on the expression of stress-regulated genes in Arabidopsis thaliana have indicated the presence of many stress-response pathways. Many drought specific transcription factors such as DREBs, SNAC, HARDY, ABF3, WRKY40, bZIP, SHN etc., have been characterized and functionally validated. In this study we analyzed the role of ICE1 (Inducer of CBF Expression), which is predicted to be transcriptional inducer of CBFs/DREB1s in imparting abiotic (drought and salinity) stress tolerance. The ICE1 gene from Arabidopsis and Rice obtained from RIKEN and RGRC respectively, were overex- pressed constitutively in Nicotiana tobaccum. Overexpression cassettes were developed by gateway cloning approach and plant transformation was done by employing Agrobacterium mediated transformation method. ICE1 gene overexpressing plants did not exhibit any abnormal phenotype. However, modifications in number of stomata and stomatal structure have been noticed. There was increase in the number of stomata compared to wild type, in AtICE1 overexpressing lines. Increase in size of guard cells and hence stomatal pore size, was noticed in OsICE1 overexpressing lines. Both in seedling and excised leaf disc assay, ICE1 transformants showed tolerance to NaCl induced stress. In leaf disc assay, ICE1 overex- pressing lines showed better chlorophyll stability (delayed senescence) than wildtype upon ethylene treatment. In pot experiments under green house conditions, the transgenic lines maintained higher rates of photosynthesis than wild type, and showed improved drought tolerance. Altered expression of ICE1 related downstream genes have been noticed in transgenic plants. ICE1 gene seems to have role in imparting salinity and drought stress tolerance, and delaying leaf senescence in tobacco.

P 4.33 - Investigation on the interactions among abscisic acid (ABA), reactive oxygen species and antioxidant defense system in transmission of drought stress signaling in ABA-deficient Arabidopsis thaliana mutant (aba1) and wild-type Arabidopsis thaliana ecotype Ozfidan C., Turkan I. (ismail.turkan@ege.edu.tr), Sekmen A., Seckin B. Department of Biology, Faculty of Science, Ege University, Bornova 35100, Izmir, Turkey. Signal transduction among abscisic acid (ABA), reactive oxygen species (ROS) and antioxidant defense system under drought stress has been an interesting research subject in the recent years. A mutant which has interrupt ABA biosynthesis is powerful tools to elucidate this relation among them and for investigating the role of ABA in stress tolerance. The objective of the present study was to reveal for a possible interrelationship among the ABA, ROS and antioxidative system in transmission of drought stress signaling by applying exogenous ABA (50 μM) to ABA-deficient Arabidopsis thaliana mutant (aba1) and its wild type Columbia (Col) exposed to 40% PEG8000 induced drought stress. ABA treatment under optimal conditions generally did not affect activities of antioxidant enzymes, H2O2 content in aba1 mutant at 6 h and 12 h. However, at 24 h of treatment, activities of all antioxidant enzymes and H2O2 content were increased, in compared to control group. Moreover, in wild type, the activities of POX, APX and GR were increased at 6 h and 12 h while activities of CAT, APX and GR were decreased at 24 h of ABA treatment under optimal conditions, in compared to control group. Drought stress increased activities of POX, APX and SOD in both ABA+PEG treated- and PEG treated-groups alone of wild type (Col) at 6 h and 12 h. However, at 24 h, activities of these antioxidants were decreased by ABA treatment under drought stress, in compared to PEG-treated group alone. In aba1, activities of all antioxidant enzymes were increased in alone PEG- and ABA+PEG-treated groups of aba1. However, this increase was higher in ABA+PEG treated-group than in PEG treated-group alone at 6 h and 12 h, while at 24 h, it was higher in later group than in former. In addition, lipid peroxidation level and content of H2O2 of ABA-deficient mutant (aba1) at 6 h and 12 h of drought treatment

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showed a decrease with ABA treatment. Therefore, we conclude that ABA protects aba1 mutant from drought-induced oxidative stress.

P 4.34 - ABA response element binding proteins are convergence points for metabolic and stress signalling pathways involving SNF1-related protein kinases Parry M.A.J.1 (martin.parry@bbsrc.ac.uk), Hirano E.1,2, Hey S.J.1, Zhang Y.H.1, Andralojc P. J.1, Primavesi L.F.1, Davies W. J.2 , Halford N.G.1

1 Plant Science Department, Rothamsted Research, Harpenden AL5 2JQ, UK; 2 The Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK. Interest in links between stress and metabolic signalling began when several mutations that affected the sugar response in Arabidopsis were found to be ABA-related and protein kinases related to the metabolic regulator, SnRK1, were placed in stress signalling pathways. SnRK1 is activated in response to high cellular sucrose / low cellular glucose and regulates carbon metabolism through the modulation of enzyme activity and gene expression. Plants contain two subfamilies of related protein kinases, SnRK2 and SnRK3 that are relatively large and diverse and are involved in signalling pathways that regulate responses to drought, cold, salt and osmotic stress. ABA-response element binding proteins (AREBPs) are a family of bZIP transcription factors that are expressed in a range of tissues and developmental stages in response to different stresses. SnRK2s have been shown previously to phosphorylate AREBPs and we have found that both SnRK1 and SnRK3 will also phosphorylate them. Peptides based on two highlyconserved target sites were phosphorylated by purified SnRK1 and by calcium-dependent and-independent activities present in crude Arabidopsis extracts. Most of the calciumindependent activity could be precipitated out of the extracts by anti-SnRK1 antisera. It is possible that the calcium-dependent activity was SnRK3 (SnRK3 is believed to be calcium- dependent because it interacts with a calcium-binding protein), making AREBPs convergence points for signalling by all three SnRK subfamilies. We hypothesise that SnRK2 and SnRK3 arose initially by gene duplication of SnRK1, and then diverged rapidly during plant evolution to fulfil new roles that enabled plants to develop networks that link stress and ABA signalling with metabolic signalling. This hypothesis is being investigated in wheat, in which we have identified AREBP transcripts in seedlings subjected to several stress treatments.

P 4.35 - Delayed leaf senescence induced drought tolerance in cereals Peleg Z., Szczerba M.W., Tumimbang E., Jauregui R.N., Liu L., Blumwald E. (eblumwald@ucdavis.edu) Dept. of Plant Sciences, University of California, Davis CA 95616, USA. Water deficit is the main environmental factor limiting cereal productivity and yield stability worldwide. Developing novel cultivars with greater drought resistance is the most viable solution to ensure sustainable agricultural production and alleviating threats to food security. The expression of a stress- and maturation-activated promoter (SARK, senescence-associated receptor protein kinase) to an isopenthyltransferase (IPT) gene promoted cytokinin synthesis and protected leaf photosynthetic activity during stress. Here, the efficiency of this approach was tested in the monocot plants rice (Oryza sativa L.) and wheat (Triticum aestivum L.). Rice cv. Kitaake and wheat cv. Bob white, were used to produce transformed homozygous lines expressing pSARK-IPT. Transgenic, wild-type (wt) and null plants, were tested in control greenhouse conditions under two water-stress treatments at different developmental stages: (i) pre-anthesis (booting) stage and (ii) post-anthesis stage (two weeks after panicle initiation), by slowly drying water-logged pots until visual stress symptoms (~12 days) appeared. Pots were then rewatered and plant productivity, morpho-physiology, and phenology parameters were collected from plants after maturation. In general, both stress treatments had a significant (P<0.001) effect on productivity parameters. When compared with the wt plants, the PSARK-IPT rice plants exhibited delayed leaf senescence under both stress treatments. Under the pre-anthesis treatment, the transgenic plants produced up to 80% of grain yield (GY) and 98% of 1000-grain weight (TGW) as compared to the wt grown under well-watered conditions, whereas the wt plants showed a dramatic reduction in GY (26%) or TGW (85%). Water stress during panicle initiation

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(pre-anthesis) causes severe reduction in flower fertility, as shown in the wt plants, with 60% reduction in grain number, while only a 20% reduction in grain number was seen in the transgenic plants. At the later stage (post-anthesis), water stress predominantly affected the translocation of assimilates from vegetative organs to the developing grain, reducing GY, nevertheless, the transgenic rice plants showed significantly greater GY than the wt. In a parallel experiment, wheat plants were grown under three irrigations regimes: (i) well-water, control; (ii) water-limited, plants were watered 50% of the control through the entire life-cycle until harvest; and (iii) terminal drought, plants were grown under normal conditions and watering was reduced at the flowering stage. These results will also be presented and discussed. Our results clearly demonstrate that the delay of stress-induced senescence can be engineered into monocot crops with significant yield improvements.

P 4.36 - Karyotype and giemsa C-banding patterns of Thinopyron elongatum Qu M.1 (xxl8761@126.com), Zhang Y.M.2 , Li J.L.2, Xu X.L.2 1

Biological Engineering Department of Food Engineering College, Harbin University of Commerce, Harbin 150076, China;

2 Life and Environment Science Institute, Harbin Normal University, Harbin 150080, China. Giemsa C-banding patterns and karyotype of chromosomes were analyzed in the root-tip cells of diploid Thinopyron elongatum. A modified seed germinating method was developed for obtaining the C-banding patterns in diploid Thinopyron elonggatum. The results of The C-banding analysis showed the significant differences among the seven pairs of chromosomes in diploid Thinopyron elonggatum. The intensive C-bands were stained steadily on the intercalary, terminal, subcentromeric and centromeric regions of Chromosomes. We found that there are three pairs of metacentric chromosomes and four pairs of submetacentric chro- mosomes in diploid Thinopyron elonggatum. The karyotype formula is 2n=2x=14=6m+8sm. Present results provided a basic cytological data and will be useful for the further studies in Thinopyron elongatum.

P 4.37 - Ectopic expression of a NAM-domain containing gene, EcNAC1, from Eleusine coracana improves abiotic stress tolerance in transgenic tobacco plants Ramegowda H.V.1, Geetha G.1, Rama N.1, Karaba N.N.1, Reddy M.K.2, Mysore K.S.3, Udayakumar M.1

(udayakumar_m@yahoo.com)

1 Department of Crop Physiology, Molecular Plant Physiology Lab, UAS, GKVK, Bangalore 560065, India;

2 International Centre for Genetic Engineering and Biotechnology, Plant Molecular Biology Division, Aruna Asaf Ali Marg, New Delhi 110067, India;

3 The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA. Abiotic stress tolerance is a multigenic trait and the threshold for tolerance differs amongst the species. Hence, identification of relevant mechanisms and genes, especially upstream regulatory genes from stress adapted crop species forms an important theme of crop abiotic stress functional genomics. Here we report the isolation and functional characterization of a full-length gene (EcNAC1), encoding NAM-domain containing transcription factor, from subtracted moisture stress cDNA library of stress adapted species Eleusine coracana. The transcript levels of EcNAC1 gene were regulated by drought, salt and ABA. Phylogenetic analysis with known rice and Arabidopsis NAC proteins and prediction of putative motifs showed unique C-terminal domain in EcNAC1. To investigate the function of EcNAC1 in plant stress response, we generated transgenic tobacco plants ectopically expressing cDNA under the control of constitutive CaMV35S or stress-inducible 4XABRE promoter. Consti- tutive expression did not show any growth retardation or visible phenotypic alterations in transgenic plants. Many transgenic lines showed significantly higher root growth and accumulated more fresh weight under simulated osmotic (PEG), salinity (NaCl) and oxidative stress (methyl-viologen) at the seedling stage. Similar response was also noticed under long-term salt and methyl-viologen induced oxidative stress. Pot grown transgenic plants maintained marginally higher stomatal conductance and CO2 assimilation rates under moderate desiccation stress. Besides, EcNAC1 over-expressing plants showed higher water retention in detached leaf screening assay. Under moisture

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stress transgenic plants showed significantly lower accumulation of O2.-, H2O2 and .OH radicals and also the extent

of lipid peroxidation was low. On alleviation of drought stress EcNAC1 transgenics showed faster recovery and accumulated more biomass. Amongst a few known SNAC target genes, HB13, MYB-CC type transcription factor, PP2C, serine-threonine protein kinase, NADPH-cytP450 oxidoreductase, Rop subfamily GTPase and ERD1 showed enhanced expression in tobacco transgenics expressing EcNAC1. Our results provide strong in vivo evidence that EcNAC1 is involved in abiotic stress responses, and confers broad spectrum stress tolerance to transgenic tobacco plants.

P 4.38 - Maize response to drought at flowering : insight from association mapping and genomic approaches Setter T.L.1,( TLS1@cornell.edu), Yan J.B.2, Masanga A.P.1 1 Dept. Crop and Soil Sci., and Dept. Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA; 2 International Maize and Wheat Improvement Center (CIMMYT), Mexico City 06600, DF, Mexico. Water deficit during the flowering and post-pollination phases severely affects kernel set and yield. In maize, yield in drought environments has been improved by selecting for genotypes with better ability to sustain floral growth and development during stress. The available evidence suggests that sensitivity to drought at this stage is regulated by response to kernel carbohydrate supply, and its interaction with abscisic acid (ABA). However, the basis of genotypic differences in this response is not known. To gain improved understanding of these differences, we have examined the levels of carbohydrate and ABA, and gene expression, in maize hybrids with contrasting tolerance to drought at flowering. A diverse set of 400 tropical maize hybrids were tested in multi-location field trials under well-irrigated control and water-stress at flowering to identify a set of hybrids that yield similarly in control conditions but are susceptible or tolerant of stress at flowering, as indicated by anthesis silking interval (ASI) and yield. In greenhouse trials, we subjected potted plants to water stress for 5 days during silking; pollination was prevented by bagging ears. Ear tips were analyzed for metabolite levels and gene expression by cDNA microarray slides (Agilent). Stress decreased grain dry weight to a much greater extent in susceptible than tolerant ears. Stress increased ABA levels similarly in all lines, and ABA-glucose ester, phaseic acid and glucose were not differentially affected, but sucrose levels per g of eartip protein were decreased more in susceptible than tolerant lines. The expression profiles in eartips showed that the susceptible lines had relatively higher transcript levels for stress genes (dehydrins, ethylene metabolism, and stress transcription factors) whereas tolerant lines had higher levels of growth-associated genes. These studies support the idea that better yield performance is related to maintenance of growth-related processes in the face of stress rather than ability to have a high expression of stress-stabilizing gene-products.

P 4.39 - In silico analysis for the presence of HARDY an Arabidopsis drought tolerance DNA binding transcription factor product in chromosome 6 of Sorghum bicolor genome Shanker A.K. ( arunshank@gmail.com), Maheswari M., Yadav S.K., Ventateswarlu B. Department of Crop Sciences, Central Research Institute for Dryland Agriculture (CRIDA), Santosh Nagar, Hyderabad 500 059, India. Water insufficiency, due to quickly escalating world population and the additional increase in water use for various other non agricultural purposes has put immense pressure on sustainable world crop production that uses a high percentage of quality water available in the planet. Water use efficiency (WUE), if increased in terms of biomass produced at the expense of transpiration measured, will have a positive effect on crop yield, under water limiting conditions. Expression of the Arabidopsis HARDY (hrd) DNA binding transcription factor (555 bp present on chromosome 2) has been shown to increase WUE in rice by Karaba et al 2007 (PNAS, 104:15270–15275). The Sorghum bicolor genome project was initiated through Community Sequencing Program (CSP) by a consortium led by Paterson et al has been completed and the version 1 of the genome is released publically (http://www. phytozome. net/sorghum). Detailed annotation of the genome is under progress as a collaborative effort worldwide. The presence of at least 60 percent similarity in nucleotide, mRNA or protein product of Arabidopsis hrd gene in sorghum offers excellent possibility of cis/trans genetic improvement of Sorghum bicolor for higher yields in the

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dry and water scarce rainfed areas of the world. In this study we took up detail analysis of the complete sorghum genome for the similarity/presence of either DNA, mRNA or protein product of the above mentioned Arabidopsis hrd DNA binding transcription factor. We conducted i) BLASTN- nucleotide query to sorghum nucleotide database, ii) TBLASTX – translated nucleotide query sequence into protein sequences in all 6 reading frames compared to sorghum nucleotide database translated on all six reading frames and iii) TBLASTN- protein query to translated 6 frame sorghum nucleotide database. Our results indicate that with a target of 3304 sequences and 738540932 total letters, there is a poor similarity of only 24 nucleotides in chromosome 1 with hrd gene. On the other hand, mRNA translated nucleotide query sequence produced matches with 11 identified regions in chromosome 1, 4, 6, 3, 10, 5, 2, 9, 7 and 8 among which 1, 4 and 6 has significant E values of less than 1.6e-18. Chromosome 6 showed a sequence match of 61.5 percent positive between 61 and 255 mRNA residues of the query region. Further confirmation was obtained by TBLASTN which showed that chromosome 6 of the sorghum genome has a region between 54948120 and 54948668 which has 80 amino acid similarities out of the 185 residues Arabidopsis hrd DNA binding transcription factor. A homology model was built with the positive match protein sequence and 20 flanking upstream and downstream sequences. SIM alignment was done and all templates with sequence identities above 25% were selected and model was generated from exPDB database scan by ProModII method. Missing side chains and deleted loops were added and energy minimi- zation was done after adding hydrogen atoms. The model was verified using Anolea, Gromos and Verify3D. Scanning the motif for possible activation sites revealed that there was a protein kinase C phosphorylation site between 15th and 20th residue. The study indicates the possibility of the presence of a DNA binding transcription factor in chromosome 6 of Sorghum bicolor with 60 percent similarity to that of Arabidopsis hrd DNA binding transcription factor.

P 4.40 - Drought-induced changes in phosphatase activities in drought tolerant and susceptible cultivars of wheat Sharma A.D. (arundevsharma@hotmail.com) Department of Biotechnology, Lyallpur Khalsa College, G T Road, Jallandhar-144001, Punjab, India. The variability in acid phosphatase activities was studied with an objective to find out its physiological role in response to drought stress. The effect of drought stress on acid P-ase activity in relationship with phosphorus was studied in drought tolerant (C-306) and drought sensitive (HD-2004) cultivars of wheat. Drought stress was imposed by withholding water irrigation to the growing seedlings in the net house conditions. The tissues (leaves and grains) were separated and acid P-ase activity, western blotting studies were carried out. After drought stress, a significant increase in acid P-ase activity was observed in leaves and grains of drought tolerant cv. C-306. However, no change was observed in drought sensitive cv. HD-2004. Immuno-blotting analysis also revealed similar type of induction of wPase-94 (band detected using antiserum in western blot analysis) expression under drought stress conditions. Imposition of drought stress caused significant decrease in phosphorous level (Pi) in both the varieties at all the stages of development. However, increased acid P-ase activity coupled with low Pi level in drought tolerant cv. 306, indicated variety specific key role of acid P-ases under drought stress in maintaining Pi level. Based upon these results, a possible physiological role of acid P-ases in wheat is discussed.

P 4.41 - Mutated genes and molecular markers: novel approaches for increasing tolerance to drought and salinity in food crops under IAEA coordinated research project: CRP D23026 Spencer M.M. (M.M.Spencer@iaea.org) Technical Officer/Plant Biotechnologist, Plant Breeding and Genetics Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture (NAFA), International Atomic Energy Agency (IAEA), Wagramerstrasse 5, P.O. Box 100, A-1400 Vienna, Austria. Despite the tremendous efforts devoted to fighting poverty and ensuring food security for all, in 2008, humankind is still seriously challenged. The situation is currently exacerbated by the huge increase of food prices alongside a significant decrease of food crop productivity in most developing countries. The efforts of the Joint FAO/IAEA Division together with renowned scientists, dedicated breeders in CG centres, NARS and farmers throughout the

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globe working either under national Technical Cooperation projects or coordinated research projects have led to the development of improved cultivars adapted to specific needs and made a major contribution worldwide. Plant breeding and in particular mutation assisted breeding is based on the fine art of selecting the ‘one of a kind’ genotype, which can bring solace to duress such as drought, high salinity content, diseases, and pests. Mutation induction is used to increase the chances of creating a favourable and permanent genetic change with possible positive impact in crop improvement. Most mutations have been induced at random, either spontaneously or through the use of experimental agents such as chemical mutagens: sodium diazide and ethyl methane sulphonate (EMS) or through physical ionizing radiations (90% of officially released mutant varieties). More recently researchers have used disruption of genes through the insertion of a DNA fragment, referred to as insertional mutagenesis to induce mutations in plants. Further- more, using a combination of mutation induction, genetic and molecular characterization techniques (marker assisted selection and T-DNA tagging) scientists have been able to perform the identification and cloning of agronomically important mutated genes involved in several favourable mutations. These mutants with desirable characteristics were either directly released for cultivation or used as pre-breeding stock in hybridisation programmes with other mutants and/or varieties to develop elite genotypes/varieties, and have made a significant contribution to boost the production of several crops including barley, rice, wheat and mungbean, and other so-called ‘orphan crops’ including bambara groundnut, amaranthus, and cowpea, which readily benefit from local traditional know-how and acceptability. The projects developed under the CRP D23026 on: ‘Identification and pyramiding of mutated genes: novel approaches for improving crop tolerance to salinity and drought’ outline an overall objective of identifying and developing superior germplasm of cereals and grain legumes with enhanced water resource use efficiency and better adapted to the climate change and variability and promote science-based breeding programmes implementation in member states.

P 4.42 - Enhanced tolerance to multiple abiotic stresses in transgenic alfalfa accumulating trehalose Suárez R. (rsuarez@uaem.mx), Calderón C., Iturriaga G. Centro de Investigación en Biotecnología-UAEM. Av. Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos, México. Abiotic-stress tolerance is a complex trait that involves tolerances to drought, flooding, extreme temperatures, soil salinity or limited mineral nutrients, and excess or deficit in light. The combinations and severity of these stresses that crops must tolerate vary with environment and year. Climate Change and limited water supply in several regions throughout the world emphasize the need to design different strategies to improve stress tolerance in cultivated plants. Genetic engineering of stress tolerance has become one of the major goals of agricultural research. Alfalfa (Medicago sativa L.) is an important forage crop in many countries with high biomass production, third most cultivated crop in the US, with high protein content and potential use as biofuel. The use of a chimeric translational fusion of yeast trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) genes led to multiple and extreme stress tolerance (Miranda et al., 2007). Here we describe the use of this TPS-TPP construct to engineer stress tolerance in alfalfa. The gene fusion was overexpressed using either the constitutive 35S promoter or the stress-regulated rd29A promoter. Transgene insertion in the genome was checked by PCR and transcript expression by RT-PCR. Several independent transgenic plants were selected in the presence of kanamycin and further analyzed. TPS1-TPS2 gene expression under the 35S promoter led to plants with stunted growth and less biomass, whereas TPS1-TPS2 expression driven by the rd29A promoter improved growth and provoked a significant increase in plant biomass at the foliage level in the different transgenic lines. Trehalose accumulated in all the different lines at similar levels upon stress conditions. Transgenic plants displayed a significant enhance in drought, freezing, salt and heat tolerance. This is the first time that genetic engineering of trehalose metabolism is reported in alfalfa, and demonstrates that it can improve multiple stress protection in this crop. Thus, the yeast TPS-TPP fusion protein represents a great potential for generating stress-tolerant crop plants for agriculture.

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P 4.43 - Proteomics analysis of drought stress-responsive proteins in wheat Tahir M., Jabeen A., Raza S., Shakeel S. (snq@qau.edu.pk) Department of Biochemistry, Quaid-a-azam University, Pakistan. The analysis of stress-responsiveness in plants is an important route to the discovery of genes conferring stress tolerance and their use in breeding programs. Proteomic analysis offers a new approach to identify a broad spectrum of genes that are expressed in living systems. We applied a proteomic approach to study changes in wheat plants in response to drought, a major environmental parameter adversely affecting development and crop yield. Two varieties of wheat (Triticum estivum L.), Punjab-96 (drought susceptible) and chakwaal-97 (drought tolerant) were grown under well-watered and induced drought conditions in three replicates. The effect of drought was highly significant in susceptible genotype as determined by some physiological parameters including; total chlorophyll, carotenoid, proline, soil moisture and relative water contents. These parameters are good indicator of drought effect even after re-watering of plants. Two-dimensional polyacrylamide gel electrophoresis (2DE) provides information on changes in abundance and electrophoretic mobility of proteins, the latter reflecting post-translational modifications such as phosphorylation and free-radical cleavage. About 412 spots were reproducibly detected and analyzed on 2-DE gels. Of these, 101 proteins showed significant change under drought condition in at least one of the genotypes. Similarly, 23 protein spots were induced greater than 2-fold in the suseptible gel compared to the tolerant gel; 37 protein spots were repressed greater than 2-fold drought and declined on re-watering. Mass spectrometry analysis led to the identification of 12 proteins. Some of identified proteins were large subunits of rubisco, thioredoxin targets and a 4-hydroxyphenylpyruvate dioxygenase etc. Further, because of contrasting changes in the tolerant and susceptible genotypes studied, several proteins emerge as key participants in the drought response. We are still in process of identifying other proteins changed under drought conditions. These results will provide new insights into our understanding of the mechanism of drought tolerance in given varieties of local wheat varieties.

P 4.44 - Effect of water deficit on leaf cuticular waxes of soybean Varillas M.A.1, Fioretti M.N.2, Baioni S.S.2, Aveldaño M.I.1, Roberto E. B.2 (fioretti@criba.edu.ar)

1 Departamento de Biología, Bioquímica and Farmacia, Universidad Nacional del Sur. 8000 Bahía

Blanca, Argentina; 2 Departamento de Agronomía, Universidad Nacional del Sur and Centro de Recursos Renovables de la

Zona Semiárida (CONICET). 8000 Bahía Blanca, Argentina. Soybean (Glycine max [L.] Merr) is the most important crop of Argentina and it has been expanding to drier areas of the country. The objective of this study was to evaluate leaf cuticular wax constituents of soybean, and the responses of these waxes to water deficiency compared with a well-watered control. Water deficit was imposed until leaf water potential drop to -2.7 MPa, at this point the plants were irrigated to field capacity and then a new dry cycle started. Several water deficient cycles were applied from flowering stage (R2) to beginning seed-filling (R5). Leaf cuticular waxes were dominated by alkanes (73% of total wax), wax esters (12%), methyl esters (6%), free fatty acids (6%) and triglycerides (4%). Compared to well-irrigated plants, water deficiency treatment caused an increase of total wax of approximately 3 times per unit area. The major alkane constituents were odd-chain components, the most abundant being the C27, C29, and C31 homologues, whereas the major wax esters were even-chain saturated fatty acids (C16-C20, predominantely) plus some 18:1 and 20:1 esterified to very-long-chain alcohols. The distribution of hydrophobic chains within the methyl esters showed this fraction to be peculiarly rich in C24, C26, and C28 components (more than 80%) whereas the proportion of free fatty acids with more than 20 C increased significantly (54% to 72%) under water deficiency. In the triglycerides fraction, 75% of the fatty acids had 16 and 18 C, including unsaturated fatty acids such as 16:1 and 18:1, 18:2 and 18:3. The five classes analyzed, accounted for 40% of the total amount of surface lipid present in irrigated plants (151 ± 10 µg dm-2) but to 60% (617 ± 37 µg dm-2) in plants under water deficiency. Water deficiency caused a large decrease in seed yield but seed weight was not so much affected, showing that soybean response to the dry cycle was mainly by reducing

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seed numbers but not seed weight. After a suitable period of rehydration, leaves produced more wax than prior to stress and chemical alteration may represent a physiological-adaptive response of soybean plants to water deficiency. This study sheds new light on our understanding of the relationship between soybean leaf wax changes in a water-limiting environment.

P 4.45 - TaABC1, a member of the abc1-like family, as a new factor in drought stress response Wang C.X., Mao X.G., Chang X.P., Jing R.L. (jingrl@caas.net.cn) National Key Facility for Crop Gene Resources and Genetic Improvement/Key Laboratory of Crop Germplasm & Biotechnology, MOA, Chinese Academy of Agricultural Sciences, Beijing 100081, China. ABC1 subfamily is a member of the protein kinase family which is known to play a significant role in signal transduction and the transmission of signals within the cell, whereas the exact functions of ABC1 are maintained unclear. A preliminary research in yeast showed that ABC1 could reduce the mis-translation of a cytochrome b and stable bc1 complex of the electron transport chain in the mitochondria. In addition, AtOSA1 (Arabidopsis thaliana oxidative stress-related Abc1-like protein) was involved in the balance of oxidative stress. We cloned an ABC1 gene from common wheat (Triticum aestivum L.) with a combination of reverse Northern blot screening, bioinformatics and RT-PCR methods. The expression pattern of TaABC1 at transcription level was investigated by real-time quantitative RT-PCR, which revealed that TaABC1 was distinctly responsive to osmoticum (-0.5MPa PEG-6000), high salinity (250 mmol L-1 NaCl), low temperature (4℃) stresses and abscisic acid (50 µmol L-1 ABA) treatment. Expressional peaks of TaABC1 responded to PEG, NaCl and 4℃ stresses appeared at 24 h, 1 h and 48 h, with 13.9-fold, 30-fold and 9.8-fold as high as that of the control, respectively. However, the expressional peak with 12 h ABA treatment was only 2-fold as high as that of the control. The results strongly suggested that TaABC1 could respond to environmental stresses. Subcellular locations of TaABC1 were the cytoplasm membrane and nucleus, evidenced by transient expression of GFP fused with TaABC1 in onion epidermal ce1ls. To investigate further whether TaABC1 is involved in the drought-stress response, transgenic plants were constructed. Compared to the wild-type and GFP-expressing plants, TaABC1- overexpressing tobacco (Nicotiana benthamiana) plants grew better and exhibited less wilt under the drought stress. Moreover, TaABC1- overexpressing plants exhibited enhanced drought resistance to water deficit, as shown by their capacity to maintain WRA (water retention ability), RWC (relative water content), and lower MDR (membrane damaging ratio) (P≤0·01) under water-stress conditions. Subsequently, we analyzed partial genome sequences of TaABC1 from Triticum urartu, Aegilopes speltoides, Ae. Squarrosa (donor species of wheat A, B (S) and D genomes), hexaploid wheat W7984 and Opata85, developed SNP markers of this gene, and mapped it on chromosome 3AL, 3BL and 3DL by the ITMI recombinant inbred lines (W7984 × Opata85), respectively.

P 4.46 - Cloning and function characterization of salt-tolerant correlative gene Ta RSTR in wheat Wang Y., Ge R.C., Huang Z.J., Shen Y.Z., Zhao B.C. (zhaobaocun@mail.hebtu.edu.cn) College of Life Science, Hebei Normal University, Shijiazhuang，Hebei 050016, China. High-salinity is a very important factor that inhibits the growth, development and reproduction of plants. Interactions between roots and salt ion can regulate gene expression to tolerate the salt-stress. The gene expression profile of salt-tolerance wheat mutant RH8706-49 under salt stress was investigated by microarray. According to the result, a salt-tolerant gene named TaRSTR (EU263918) was cloned. The sequence possesses a RING-finger domain, which is a specialized type of Zn-finger. The relative expression of the TaRSTR gene was rised at 1h under NaCl and PEG treatment in leaf and root according to real-time PCR. Function analysis of TaRSTR overexpression in Arabidopsis showed that root growth conditions of seedlings under salt stress in transgenic plants were appreciably better than col-0 control plants. The older seedlings of transgenic plants under salt stress were stronger than control, which were more vertical, and their legumens were more fullness. The results indicated that overexpression of TaRSTR gene improved the salt-tolerance in Arabidopsis. It was presumed that TaRSTR gene was invovled in ionic stress response and could positive regulate the stress pathways. The transgenic Rice of TaRSTR gene overexpression showed that big seedlings’ survival ratio were

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different between transgenic plants and the control. The former was higher than the latter in evidence, and the same to RWC. It indicated that overexpression of TaRSTR gene increased the salt-tolerance of Rice and the ability of holding water. TaRSTR locates in nuclear and has potential phosphorylational sites. The results indicated that the gene might encode a transcription factor regulated by phosphorylation, which involved in early response under stress.

P 4.47 - An integration mechanism for photoperiodic and stress signaling Jia W.S. (jiaws@cau.edu.cn) College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. Control of life cycle as mediated by photoperiodic signaling is a fundamental mechanism for plants to cope with the seasonal changes, and modulation of the life cycle is often a powerful strategy for plants to cope with a variety of environmental stresses. Until now, how the life cycle can be modulated by environmental stresses remains unknown. Here we describe that a protein tyrosine phosphatase, FPTP1, may be a critical candidate signal mediating the life cycle modulation in response to environmental stresses. Fptp1 mutant showed a phenotype somewhat similar to phyB, but flowered earlier than did phyB as well as the wild type under both long-day and short-day conditions, and by contrast, over-expression of FPTP1 delayed flowering and reversed the phynotype of fptp1. Mutation in FPTP1 significantly promoted FT expression but had no effect on CO expression. In both yeast and plant, FPTP1 was demonstrated to specifically interact with the N-terminal but not the C-terminal of phyB. CO-transgenic experiment has revealed that FPTP1 could negatively regulate CO protein abundance, a similar role of phyB in CO regulation. Collectively, our data demonstrate that FPTP1 is a intermediate signal mediating the phyB controlled CO degradation. Because FPTP1 is proposed to be a stress responsive, it likely functions as a gate that leads the stress signaling into the photoperiodic signaling pathway.

P 4.48 - A null mutation in the stress signaling regulator SAL1 results in drought tolerance Wilson P. B.1,2 (barry.pogson@anu.edu.au), Estavillo G.M.2, Pogson B.J.2

1 Crop Adaptation, CSIRO Plant Industry, Black Mountain Laboratories, Canberra, ACT 2601, Australia; 2

Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia.

The drought tolerant alx8 Arabidopsis mutant was originally isolated due to its increased expression of the antioxidant ascorbate peroxidase 2 (APX2) under normal conditions and after high light stress. The alx8 point mutation was subsequently mapped to the SAL1 gene (FRY1/At5g63980) and was shown to result in the absence of the SAL1 protein in leaf material. The SAL1 protein is a bifunctional phosphatase, active against inositol polypho- sphates and bisphosphate nucleotides, and has been implicated in the negative regulation of stress response pathways, RNAi, and light control of cell elongation and flowering. Previously identified mutations in SAL1, including fiery (fry1-1), were reported as being more sensitive to drought imposed by detachment of rosettes. We have demonstrated that alx8, fry1-1 and a T-DNA insertional knockout allele all have markedly increased resistance to drought when water is withheld from soil-grown mature intact plants. Given SAL1’s key role in a number of signalling pathways, alx8 provides an ideal candidate to explore the links between molecular changes and the resulting drought tolerance. Molecular analysis has revealed constitutively altered expression of more than 1800 genes in both alx8 and fry1-1. The up-regulated genes included some characterized stress response genes, but few are inducible by ABA. Metabolomic analysis revealed that both mutants exhibit a similar, dramatic reprogramming of metabolism, including increased levels of the polyamine putrescine implicated in stress tolerance, and the accumulation of a number of unknown, potential osmoprotectant carbohydrate derivatives. Interestingly, there was no substantial difference in plant water use efficiency (WUE) between alx8 and Col-0 under well watered conditions, as measured by carbon isotope discrimination. This indicated that alx8 might possess a unique mechanism of drought tolerance that could prove beneficial to the development of dryland agricultural varieties.

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P 4.49 - Effect of water deficit on carbohydrate partitioning and activities of sucrose metabolizing enzymes in seedlings of rice Xu W., Cui K.H. (cuikehui@mail.hzau.edu.cn), Huang J.L., Nie L.X. Key laboratory of Huazhong Crop Physiology and Production, Ministry of Agriculture; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China. Generally, plant often grows more roots in comparison to aboveground parts under water-stressed condition. To understand the underlying mechanism for the compensatory growth of roots in rice, two cultivars (Zhenshan 97, a lowland indica rice, IRAT109, a drought-resistant upland japonica rice) were grown hydroponically for investigating the relationships among root growth, carbohydrates partitioning, activities of enzymes related to sucrose transformation (Sucrose-phosphate synthase, SPS, Sucrose Synthase SS, Invertase, INV) at the early stage of growth under water deficit imposed by application of PEG6000. (1) Shoot dry weight (DW) decreased significantly under water stressed condition. However, root dry matter declined slightly or increased. So, the ratio of root to shoot increased observably in comparison with that under well-watered condition. (2) Under water deficit, the concentration of soluble carbohydrates in leaves and roots increased significantly and decreased in stems. Starch content increased only in stems under water stressed condition. Percentage of soluble carbohydrates markedly increased in roots under water deficit, suggesting that more carbohydrates were distributed to roots. Percentage of starches in roots had no obvious change, however, the sharp increase in stems and decreases in leaves were observed. (3) Under water-stressed condition, SPS activities increased in comparison with those under well-watered condition. Both of acid Inv and SS activities in leaves decreased induced by water deficit. However, acid and neutral INV activities were increased evidently. (4) Root DW, shoot DW and ratio of root to shoot were increased in the case of adding more Ca2+ in PEG solution compared with those without adding Ca2+. Interestingly, DW of root and shoot was decreased in PEG solution with EGTA, which preferentially binds Ca2+ in comparison with those in PEG solution with Ca2+. Under drought, SPS activities in leaves and stems and acid INV activities in root increased with more Ca2+ than those with EGTA. Generally, the results suggest that ratio of root to shoot was increased under the drought condition, which may attribute partly to more soluble carbohydrates distribution to roots. Increase in SPS activity in leaves and acid INV in roots may accelerate translocation of more soluble carbohydrates to roots as it is considered that carbohydrates are transported as sugar. Also, the results suggest that Ca2+ may relief the inhibitions on growth caused by water deficit by increasing the activities of SPS in leaves and acid INV in roots.

P 4.50 - Isolation and functional identificaiton of ERF transcription factors in wheat Xu Z.S., Li L.C., Chen M., Ma Y.Z. (mayouzhi@yahoo.com.cn) National Key Facility of Crop Gene Resources and Genetic Improvement (NFCRI), Key Laboratory of Crop Genetics and Breeding, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing 100081, China. Abiotic and biotic stresses, such as drought, high-salinity and low-temperature, as well as pathogen and pest attack, have adverse effects on plant growth and crop yield. To survive, plants have evolved defense mechanisms to perceive signals from their surroundings and to appropriately respond to the different stresses by modulating the expression of responsive genes. Transcription factors function pivotally in signal transduction to activate or suppress defense gene expression, as well as in the regulation of interaction between different signaling pathways. More than 1,500 genes encode transcription factors in the Arabidopsis genome. Of these, the DREB/ERF family has been extensively studied recently. Several ERFs function pivotally in elevating tolerance to abiotic and biotic stresses by interacting with CRT/DRE and GCC-box elements present in the promoters of RD/COR and PR genes. We isolated four ERF genes from wheat (Triticum aestivum) by screening a drought-induced cDNA library. These ERFs were shown to regulate many key functions, including abiotic and biotic stress responses. Of them, homologs

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of the ERF gene, TaERF1, were located on chromosomes 7A and 7B. Protein interaction assays indicated that TaERF1, with a putative phosphorylation site (TPDITS) in the C-terminal region, was a potential phosphorylation substrate for TaMAPK1 protein kinase. Deletion of the N-terminal motif enhanced the interaction of TaERF1 with TaMAPK1. The predicted TaERF1 protein contained three putative nuclear localization signals (NLSs), and three NLSs modulated synergistically the activity of subcellular localization. As a trans-acting factor, TaERF1 was capable of binding to the GCC-box and CRT/DRE elements in vitro, and of trans-activating reporter gene expression in tobacco (Nicotiana tabacum L.) leaves. Transcription of the TaERF1 gene was induced not only by drought, salinity and low-temperature stresses, but also by infection with Blumeria graminis f. sp. tritici. Furthermore, overexpression of TaERF1 activated stress-related genes, including PR and COR/RD genes, under normal growth conditions, and improved pathogen and abiotic stress tolerance in transgenic plants.

P 4.51 - Caryopsis dormancy and seedling drought tolerance of the model plant, Brachypodium distachyon Yan J.1, 2, 3, Cheng J.P.3, Xu C.M.3, Nevo E.1, Gutterman Y.2 (Gutterma@gmail.com)

1 Department of Evolutionary and Environmental Biology and the Institute of Evolution Faculty of Science and Science Education, University of Haifa, Haifa 31905, Israel;

2 Albert Katz International School for Desert Studies, Ben-Gurion University, Sede Boker 84990, Israel; 3 Institute of Triticeae Crops, Guizhou University, Guiyang 550025, China. Brachypodium distachyon is a monocot grass plant and widely distributed in Europe, Mediterranean region, Pakistan, India, Kashmir and Tibet in China. As a new potential model plant species, B. distachyon represents important traits for study on the cytogenetics, molecular genetics, etc, in recent years. In Israel, ecotypes of B. distachyon are abundant and occupy diverse habitats ranging in montane vegetation of Mt. Hermon, Mediterranean woodlands and shrublands, Semi-steppe shrublands and the desert. In this study, the caryopsis dormancy and seedling drought tolerance of 67 B. distachyon ecotypes originating from four different locations in Israel were investigated. The obtained results showed that the seed of B. distachyon developed dormancy. The storage time had a significant effect on caryopsis dormancy and germination. The afterripening process could be accelerated, and caryopses dormancy could be broken when storaged at high temperature (40℃). The order of dormancy depth among four populations was Sede Boker > Yatir > Tibigha > Carmel. Similarly, the order of the seedling revival ability after periods of drought was Sede Boker < Yatir < Carmel =Tibigha. Thus, dormancy depth is positively and significantly correlated with seedling drought tolerance. Furthermore, both the dormancy depth and seedling drought tolerance were found to be correlated negatively with the mean annual rainfall at four local sites. The present results demonstrated that B. distachyon populations have evolved adaptive mechanisms by regulating the time of germination and seedling revival strategy against drought stress. These results will provide a further study reference for physiological ecology and genetic characteristics of wheat and barley crops, temperate cereals and pasture plant.

P 4.52 - Gas exchange, stable carbon and nitrogen isotopes and real-time PCR reveal genotypic differences in durum adaptation to drought and salinity Yousfi S.1, Serret M.D.1, Araus J.L.1, 2 (j.araus@cgiar.org) 1 Plant Physiology Unit, Barcelona University, Diagonal, 645, 08028 Barcelona, Spain; 2 International Maize and Wheat Improvement Center (CIMMYT), Texcoco, Mexico. Durum wheat is the most cultivated crop in the south and east Mediterranean basin where drought is the main stress limiting productivity. One of the ways of increasing yield is irrigation. However, this may expose soils to progressive salinisation. Selecting genotypes more resistant to drought or with a higher salt tolerance are complementary ways of improving durum wheat adaptation in the Mediterranean. We compared growth, physiological response and gene expression of different durum wheat genotypes placed under diverse water and salinity conditions. Four recombinant inbred lines (RILs) derived by single seed descent from the cross ICD-MN91–0012 between Lahn and Cham 1 were selected based on their contrasting tolerance to grow under

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continuous salinity while showing quite similar biomass in absence of stress. Genotypes were grown in pots within a growth chamber for over one month. Treatments were imposed one week after germination. The combination of two water regimes (container capacity and 35%) and three salinity levels (Hoagland solution formulated with deionized water, 12 dS m-1 and 17 dS m-1 water, respectively) were assayed, accounting for a total of 5 different treatments (35% pot capacity and 17 dS m-1 water was not tested). Watering at 100% and 35% of container capacity with 17 dS m-1 and 12 dS m-1, respectively, were the most stressful treatments, diminishing biomass near 75% compared with stress-free plants. For each of the four stress treatments the two tolerant RILs showed consistently higher biomass, nitrogen concentration, photosynthesis, stomatal conductance, and stable carbon isotope discrimination and nitrogen isotope composition than the two susceptible RILs. In the other hand the transcript levels of specific genes reported for wheat to have a role in response to water stress (TaDREB1 A, TaDREB 2B) salinity (NHX) or involved in key steps of nitrogen metabolism (GS1, GS2) were quantified with real-time PCR based in SYBR green. Tolerant RILs did not show a consistent pattern of transcriptional response across treatments and candidate genes assayed.

P 4.53 - Expression pattern under different abiotic stresses and haplotype analysis of tapk7 in common wheat Zhang H.Y. 1, 2, Mao X.G.1, Jing R.L.1 (jingrl@caas.net.cn), Xie H.M.2, Chang X.P.1

1 National Key Facility for Crop Gene Resources and Genetic Improvement / Key Laboratory of Crop

Germplasm & Biotechnology, the Ministry of Agriculture / Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China;

2 College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China. Protein phosphorylation/dephosphorylation are major signaling events induced by abiotic stresses in higher plants. Sucrose nonfermenting 1-related protein kinase 2 (SnRK2), which belongs to serine-threonine protein kinase, plays an important role in the process of sugar signal transduction. It is reported that the gene family is activated by hyperosmotic stress and relays the stress signal via phosphorylation. TaPK7, a member of SnRK2 gene family of common wheat, was isolated based on SAPK7 (AB125308) by in silico cloning and RT-PCR. The TaPK7 protein has 357 amino acids with an estimated molecular mass of 42 kD and an isoelectric point of 5.47. Phylogenetic analysis results showed that TaPK7 was high homologous to the orthologous genes from rice, maize and barley, which were also induced by abiotic stresses. RT-PCR was introduced to investigate the expression pattern of TaPK7. The results revealed that TaPK7 was obviously responsive to high salinity, hyperosmolality, low temperature (4℃) stresses and abscisic acid (ABA) treatment, but with a significant different expression patterns. The sensitivity degrees of TaPK7 responding to stresses was in the order of high salinity ＞ hyperosmolality ＞ low temperature (4℃) ＞ ABA. The relationship between single nucleotide polymorphism (SNP) in TaPK7 and drought tolerance was investigated by sequencing 45 common wheat accessions and 5 diploid species of wheat relatives. Total of 64 SNPs and 9 InDels were detected in all 220 448 bp nucleotide acids, which demonstrated the frequencies of 1 SNP /3 445 bp and 1 InDel /24 494 bp, respectively. The nucleotide diversity value in non-coding region was higher than that in coding region, which suggested that the coding region went through stronger selection pressure than non-coding region. Ka/Ks value of TaPK7 was 0.415, indicated TaPK7 a conservative gene. Sixteen SNPs were observed in coding region, and most of them happed in drought-tolerant accessions. A total of 21 haplotypes were identified from the plant materials. Among them, 7 haplotypes of TaPK7 were only constituted by accessions with drought-tolerant or drought- sensitive characteristics, 11 haplotypes contained moderate-drought-tolerant accessions, but 3 haplotypes contained both types of accessions. SNPs in TaPK7 were correlative with drought tolerance, but it couldn’t explain the mechanism of drought tolerance completely in wheat. Function characterizing of TaPK7 drought-tolerant haplotype is ongoing.

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P 5.01 - Estimation of resistance of diploid and tetraploid wheat genotypes to drought stress Abbasov M.(mehraj_genetic@yahoo.com), Quliyev S., Jafarova R., Sheyxzamanova F., Rzayeva S., Babayeva S. Genetic Resources Institute of ANAS, Baku, Azerbaijan. The aim of investigation was to determine drought accessions among diploid and tetraploid wheat genotypes based on physiological parameters and field characterization, as well as to clarify molecular genetic bases of their stress tolerance. The experiments were carried out on 53 diploid and tetraploid wheat genotypes. The studied accessions were first tested for seed germination percentage, as well as for chlorophyll content under stress (10 atm. PEG) and normal condition and grown in irrigated, rainfed lands and comparatively analyzed based on 8 yield components. The tolerance indices on the base of physiological traits and main yield components directly affecting wheat productivity were computed and accessions were classified for their stress tolerance. As the result of these laboratory and field experiments from 53 wheat accessions 14 genotypes were selected as a high tolerant to drought stress, some of which can be directly sown in drought lands, and some can be used as a valuable gene source in practical breeding programs. Molecular genetic analysis was carried out in order to reveal changes occurred in structure and functioning of DNA which is not homogenous. Labile DNA is more active and localized in euchromatin, whereas heterochromatin contains stabile DNA fraction which closely connected with histons. During molecular analysis it was determined that in tolerant genotypes the active genome part – labile chromatin DNA increased resulting in intensification of transcription and much more RNA synthesis. Contrary in susceptible varieties the decrease of RNA and DNA fractions in quantity was observed. Results obtained from this investigation shows that changes occurred in genome structure and functioning can be accepted as stress resistance indices of plants and can be used in explanation of plant resistance and molecular-genetic mechanisms.

P 5.02 - Genetic assay of some traits in wheat (Triticum aestivum L.) under drought stress condition using Generation Mean Analysis Ahamadi J.1 (njahmadi910@yahoo.com), Fotokian M.H.2, Orang S.F.3

1 Imam Khomeini International University, Qazvin, Iran; 2 Shahed University, Iran; 3 Tarbiat Moddarres University, Tehran, Iran. Awareness of gene action of traits is very important in plant breeding methods. Generation mean analysis (GMA) using parents (P1 & P2) and their progenies (F1, F2, BC1 & BC2) in two mating groups was used to study the type of gene action and the best genetically model of traits under drought stress condition. The experiment was conducted using a randomized complete block design with three replications for each mating group. Generation mean analysis was performed using Mather and Jinks model and joint scaling test. The nine traits included spike length, spike number, peduncle length, awn length, grain yield, plant height, spike weight, grains per spikes and 100 grain weight were evaluated. The analysis showed disagreement of additive-dominance model for all traits, resulted that there is epistatic non-allele interactions between the genes of each trait. The distribution of traits was continuous in F2 and backcrossed populations, as a reason for polygenic inheritance of the traits. For the majority of the traits, additive gene effect was significant, but its magnitude was less than dominant gene effect. The amount of h/d for many traits such as grain yield was higher than one (h/d>1), indicated the overdominance of dominant gene effects in F1 progeny.

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P 5.03 - Genetic dissection of root architecture at seedling stage in durum wheat

Amamou A.1(amamou_ali@yahoo.fr), Maccaferri M.2, Sanguineti M.C.2, Kehel Z.3, Nachit M.3, Habash D.4, Nserallah N.1, Bort J.5, Latiri K.6, Kader A.A.7, Tuberosa R.2

1 National Institute of Agronomical Research, INRA Settat, Morocco; 2 Dept. of Agroenvironmental Sciences and Technology, University of Bologna, Italy; 3 International Center of Agricultural Research in Dry Area, ICARDA Aleppo, Syria; 4 Plant Science Dept., Centre for Crop Genetic Improvement, Rothamsted Research, Harpenden, Hert-

fordshire AL5 2JQ, UK; 5 Departamenta de Biologia Vegetal, Barcelona, Spain; 6 INRAT, Rue Hedi Karray, 2049 Ariana, Tunisia; 7 General Comission for Scientific Agricultural Research (GCSAR), Damascus, Syria. Limited information is available on the genetic control of root traits in durum wheat, a crop largely grown in rainfed areas with low rainfall. In the EU-funded TRITIMED Project, 112 RILs of the durum mapping population Lahn x Cham1 were evaluated for root and shoot traits at the seedling stage under controlled conditions, using two methodologies (‘paper roll’ and ‘flat paper sandwich’). Covariance analysis revealed significant, albeit weak, linear effects of kernel weight only for total root length, root dry weight and shoot dry weight. Significant genetic variability among RILs was observed for all traits with both root evaluation systems, except for shoot dry weight in paper sandwich. In most cases, a transgressive segregation was observed in both directions, thus indicating that both parental lines contributed the alleles increasing the investigated traits. Correlation analysis suggested that root and shoot features were only partially controlled by common sets of genes. QTL analysis identified some chromosome regions that significantly influenced root and shoot features architecture. QTLs for seedling root and shoot traits were identified on all the chromosomes and in particular QTL clusters for both root and shoot characteristics were identified in the distal portion of chromosomes 1B, 4A and 4B and in the central portion of chr. 5A. The limited influence of maternal effects due to seed size on seedling traits was confirmed by the negligible overlap between the relevant QTLs. Subsequently, we investigated the co-location between the QTLs identified at the seedling stage and other QTLs for grain yield, yield components and other adult plant traits related to drought resistance measured in 27 field trials conducted under a wide range of water availability across the Mediterranean Basin (Nachit et al., unpublished). In particular, two QTLs for shoot length (paper roll method) were identified on chr. 2A (near Xwmc382) and 4A (near Xbarc343) regions were involved in the control of grain yield, stability and thousand kernel weight (TKW) as from field experiments. An additional overlap was detected for the above-mentioned 5A QTL cluster for root and shoot traits and a TKW QTL. Overall, the overlap was quite modest and thus provides limited opportunities from a breeding standpoint, suggesting that in this population the study of root architecture at the seedling stage does not appear to be diagnostic for field performance. We are presently investigating the relationship between QTLs for root features at the seedling stage and in the field.

P 5.04 - Molecular breeding for drought tolerance in potato Anithakumari A.M.1, Visser R.G.F.2, Linden V.D. C.G.2 (gerard.vanderlinden@wur.nl) 1 Graduate School Experimental Plant Sciences, Wageningen UR Plant breeding, WUR, PO Box 386,

6700 AJ Wageningen, The Netherlands; 2 Wageningen UR Plant breeding, WUR, PO Box 386, 6700 AJ Wageningen, The Netherlands. Potato is an important food crop, yet it is relatively susceptible to drought. As a first step towards identifying the genetic basis for drought tolerance in potato, we make use of diploid potato populations that have been genetically well characterized (CxE, SHxRH). For genetic dissection of potato drought tolerance, we have expanded a backbone AFLP/SSR genetic map of CxE with markers in members of gene families that have been shown to be involved in the regulation of drought response. These include Myb genes, WRKY genes and Peroxidases by employing a PCR based method called Motif directed profiling (MdP). We also populated the CxE genetic map

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with 165 SNPs. The SNPs were discovered in public EST databases using the QualitySNP software (Tang et al, 2005) and detected with the Illumina GoldenGate assay. The same set of SNP markers was mapped in the SHxRH population, which resulted in approx. 100 SNPs mapped in both populations, allowing alignment of the CxE genetic map with the SH x RH genetic map. This enabling us to make use of the extensive genetic and sequence information of the SHxRH population and the RH genome sequence. The CxE population has been extensively phenotyped for drought tolerance under greenhouse conditions by measuring traits like Relative water content of leaf, ∆13C as a measure of Water Use Efficiency, Chlorophyll fluorescence, Shoot biomass and tuber yield. The progeny displayed a wide contrast for drought tolerance, with individuals surviving and recovering completely after 3 weeks of drought, and others completely wilted beyond recovery. Heritabilities of the traits were determined and QTLs identified for tuber number, tuber weight, plant height, Shoot fresh and dry weight, ∆13C and relative water content of the leaf under drought treatment. In the future, we will identify the candidate genes by zooming into the drought tolerance QTLs that we identified in CxE and by expression studies.

P 5.05 - QTL analysis of root development and distribution in common bean under contrasting water availability Asfaw A.1 (asrat.asfaw@gmail.com), Blair M.2, Polania J.A.2, Beebe S.2, Rao I.M.2

1 Awassa Agricultural Research Center, P.O.Box 6, Awassa, Ethiopia; 2 International Center for Tropical Agriculture (CIAT), A.A. 6713, Cali, Colombia. Drought is the major abiotic constraints contributing to yield reduction in common beans (Phaseolus vulgaris L.). Drought avoidance by increasing extraction of soil moisture and result in greater yield under water deficit conditions is a mechanism that receives most attention in common bean breeding. A recombinant inbred line population of DOR-364 x BAT-477 was evaluated in a greenhouse soil tube method to quantify root development and distribution under simulated soil drying (terminal drought) and non-stress conditions and correlate with field performance. The recombinant inbred line population expressed phenotypic variation and transgressive segregation for root development and distribution. A composed interval mapping analysis using a genetic map constructed with 191 genetic markers that covered all 11 linkage groups of common beans genome identified seven significant QTL for five root traits. The QTLs identified were one for total root length on linkage group B4, two for specific root length on linkage group B10 and one for deep rooting ability on linkage group B11 under terminal drought stress and one for total root length on linkage group B4 and two for deep rooting ability on linkage groups B2 and B10 under non-stress conditions. Total root length, specific root length and deep rooting ability seem a logical target to improve drought adaptation in common beans.

P 5.06 - Marker-assisted introgression of quantitative trait loci (QTLs) for post-flowering drought tolerance (stay-green) in sorghum [Sorghum bicolor (L). Moench] Bantte K.1(kassahunb@gmail.com), Hash C.T.2, Bidinger F.R.2 1 Jimma University, Jimma, Ethiopia; 2 International Crop Research Institute for the Semi Arid Tropics (ICRISAT), Patancheru, India. Drought is a major limiting factor to agriculture and is considered as the most important cause of yield reduction in crop plants especially in water-limited areas where most of the world’s poorest farmers live. Development of drought tolerant crop varieties will enhance food production and the livelihoods of farmers in these areas. Reduced leaf senescence (stay-green) has been demonstrated to provide a significant measure of drought tolerance under post-flowering moisture stress in grain sorghum and a number of quantitative trait loci (QTLs) associated with this trait have been identified and mapped. However, transfer of these QTLs into high yielding and drought susceptible varieties is just being initiated. In the present study, four stable QTLs (StgB, Stg1, Stg3 and Stg4), associated with post-flowering drought tolerance (stay-green) were selected and transferred from post-flowering drought tolerant (stay-green) donor parent

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(B35) to the drought susceptible (senescent) recurrent parent (R16) using molecular marker-assisted backcrossing (MABC). The stay-green backcross lines were evaluated for their agronomic and drought tolerance (stay-green) related characters under well watered and water-stress conditions in the field for two seasons (2004/05 and 2005/06). Based on the evaluation, introgression line, RSG 04001/ 05001 was found to be the most promising line both in terms of its grain yield and stay-green (% green leaf area). Besides high% green leaf area, the stay-green genotypes had high chlorophyll content compared with the senescent lines showing the relationships among these traits. The correlations of relative grain yield to relative% green leaf area in the stress environments was also highly significant (R2 = 0.47 in 2004/05 and R 2 = 0.77 in 2005/06) indicating the contribution of stay green to grain yield.

P 5.07 - Mapping QTLs linked to physio-morphological and plant production traits under drought stress in rice (Oryza sativa L.) Beena R.1(beenaajithkumar@rediffmail.com), Rajendra Prasad N.S.2, Manikanada Boopathi N.2, Thandapani V.1, Chandra Babu R.2 1 Department of Crop Physiology; 2 Department of Biotechnology, Tamil Nadu Agricultural University-641 003, Coimbatore, India. Drought stress is a serious constraint to rice production and yield stability in rainfed ecosystems. QTL discovery should be viewed as the first step of a larger process aimed at identifying the molecular basis of drought tolerance. Progress made in this direction in rice is mostly concentrated on indica x japonica crosses. So in the present study, recombinant inbred (RI) lines developed from a cross between two indica cultivars, IR20 and Nootripathu were used. In trial 1, 200 F8 RI lines were evaluated for physio-morphological traits under managed stress environment (MSE) at Coimbatore during the dry season. Water stress was imposed by withholding irrigation during the reproductive stage. Water stress caused 50 percent reduction in biomass on an average across the RI lines. Water stress indicators were negatively correlated with biomass under stress. Analysis of QTLs for physio-morphological traits identified a total of 41 QTLs which individually explained 5.3 to 15.7 percent phenotypic variation. In trial 2, QTLs linked to production traits under drought stress in field were mapped by evaluating 340 recombinant inbred lines of IR20X Nootripathu under rainfed conditions in the target populations of environment (TPE) at Paramakudi, Tamil Nadu. The stress was mild in this experiment but the crop is purely under rainfed condition throughout the cropping season. Significant differences were observed among the RI lines for plant production traits under both rainfed and irrigated conditions. Transient drought under rainfed condition caused an average reduction of 38.7 percent in grain yield across the RI lines. Plant height, panicle length, harvest index and straw yield had positive correlations with grain yield but days to 50 percent flowering had negative correlation with grain yield under rainfed condition. Analysis of QTLs for yield and yield components identified 88 QTLs with phenotypic variation ranging from 2.3 to 20.0 percent. In the same trial, 100 QTLs were identified for yield and yield components under irrigated condition with phenotypic variation ranging from 2.2 to 53.7 percent. QTLs for production traits were overlapped with some of the physio-morphological traits indicating the pleiotropic effects of yield QTLs under drought stress. Some of the markers showed pleiotropic effect whereas some others showed consistency of QTLs for the same trait across the trials. In addition, the markers RM212 on chromosome 1, RM263 on chromosome 2, and RM242 on chromosome 9 were previously reported as QTLs linked to various drought resistance traits in different genetic backgrounds in rice.

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P 5.08 - Molecular characterization of genes involved in leaf, silk and root growth maintenance in maize under water-limited condition Bencivenni C.1(c.bencivenni@cgiar.org), Shah T.1, Reif J.C.2, Davenport G.1

1 IRRI-CIMMYT Crop Research Informatics Laboratory (CRIL), KM.45 Carretera Mexico -Veracruz, colonia El Batan, Texcoco, Estado de Mexico 56130, Mexico; 2 State Plant Breeding Institute and of the Experimental Station of Plant Breeding, Fruwirthstr. 21, D-70593 Stuttgart, Germany. The inhibition of plant growth is recognized as the primary effect of water deficit. The effort to minimize the impact of drought on growth and consequently yield requires new approaches to bridge the gap between traditional breeding and molecular genetics. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks, signal transduction pathways, and the expression of stress-related genes and metabolites. The objective of the study is to understand the mechanisms involved in plant growth maintenance during water deficit by comparing gene expression in well-watered plants with those under water stress and to try to associate the differentially expressed genes with genomic regions linked with drought traits. To identify genes associated with growth maintenance under drought, transcriptome analyses of four maize lines from a CIMMYT mapping population (2 drought-tolerant and 2 drought susceptible) were performed in a multiple-organ study (leaf, silk and root) under well-watered and water-deficit conditions (at water potential of -0.5 MPa). The studied lines were chosen for their contrasting responses of leaf elongation rate to soil water potential and were tested in controlled environments (greenhouse and growth chamber experiments for silk and root tissue in France and Switzerland), and in field environments (for leaf and silk tissue in Mexico). EASE pathway assignments tool allows to identify general classes of genes that are over-represented and was used to classify the differentially expressed genes from the microarray expression profiling in functional categories of interest related to growth maintenance. It revealed that 12, 112, 58 and 92 candidate genes are associated with growth functional category and 102, 886, 415 and 848 are associated with diverse metabolic processes, respectively in root and silk tissue from the greenhouse experiments and in leaf and silk tissue from the field experiments. The growth-associated genes include important enzymes such as alpha- and beta-expansins, xyloglucan endo-transglucosylase/hydrolase; and important phytohormones factors such as auxin response factor, brassinosteroid precursor or ethylene response factor. Association studies will be carried out to re-confirm the selected candidate genes using an allele-mining approach. By re-sequencing these genes in genotypes known to have different responses to growth maintenance under drought, we will look for SNPs that are associated with growth maintenance within a diverse panel of maize lines. The expected output will be a drought genetic map for tissue elongation, combining genes expression data, QTLs data, and markers data (SSRs, RFLPs, SNPs).

P 5.09 - Field performance of spring wheat transformed with the mtld gene for drought tolerance Byrne P.F.1 (patrick.byrne@colostate.edu), Mergoum M.2, Castelbaum E.1, Martin B.3

1 Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA; 2 Department of Plant Sciences, North Dakota State University, Fargo, ND, USA; 3 Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, USA. Drought stress is a major constraint on the growth and productivity of wheat (Triticum aestivum L.). One strategy to improve drought tolerance in this crop is to transform plants with genes that protect against the effects of dehydration. The mtlD gene from Escherichia coli encodes mannitol-1-phosphate dehydrogenase, which enables the biosynthesis of mannitol, a sugar polyol believed to protect cell membranes or other components. Abebe et al. (2003) reported that under greenhouse conditions some transgenic mtlD wheat lines accumulated moderate levels of mannitol and showed improved tolerance to water and salinity stress. The objectives of our study were to evaluate the field performance of six mtlD wheat lines under well-watered and moisture stress conditions. The mtlD gene under the control of a constitutive promoter was inserted into the spring wheat cv. ‘Bobwhite’; the enzyme was expressed in the cytosol of four lines and in the chloroplast of two lines. The field study was conducted in 2006 and 2007 in Fort Collins, Colorado, USA (side-by-side well-watered and moisture stress trials)

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and at two rainfed sites in Casselton and Hettinger, North Dakota, USA. Each trial was a randomized complete block design with three or four replicates. Entries common to all trials were six mtlD lines, an empty vector control, the parental cultivar ‘Bobwhite’, and the conventional cultivar ‘Reeder’. Plots were evaluated for developmental, morphological, yield-related, and physiological traits. Mean grain yield in the eight environments ranged from 1028 to 2019 kg/ha. Analysis of variance revealed that the effects of year, location, moisture treatment, and entry were all significant (P<0.05) for most traits. With few exceptions, results revealed no significant improvement of any of the transgenic lines over Bobwhite under either well-watered or stress conditions. Single degree of freedom contrasts for cytosol lines vs. chloroplast lines were also non-significant in most cases. However, for a few key traits such as biomass, kernel number, and average kernel weight, some mtlD lines were numerically, if not statistically, superior to Bobwhite in some environments. Additional studies on mRNA expression and mannitol accumulation in the mtlD lines are underway and may help explain our field results. Evaluation under more severe moisture stress or evaluation of additional mtlD lines might provide more promising results for the potential incorporation of this gene into wheat cultivars.

P 5.10 - Molecular genetic mapping of terminal drought tolerance genes in wheat Çakir M.1 (M.Cakir@murdoch.edu.au), Conocono E.2, Drake-Brockman F.2, Waters I.2, Rebetzke G.3, Wilson R.2, Barclay I.2, McLean R.2, Setter T.2

1 Western Australian State Agricultural Biotechnology Centre, Murdoch University, Murdoch, WA 6150, Australia;

2 Crop Breeding, Department of Agriculture and Food Western Australia, Locked Bag 4, Bentley Delivery Centre, South Perth, WA 6983 Australia;

3 CSIRO, Plant Industry, PO Box 1600, Canberra, ACT 2601 Australia. Consistently high values of stem carbohydrate concentrations at flowering occur in WA wheat varieties grown in the field, and this makes this a high priority for evaluation as a potential drought tolerance mechanism. The objectives of this study are to evaluate the impact of stem carbohydrates on drought tolerance at grain filling stages (terminal drought), map the genes responsible for the accumulation of stem carbohydrates, develop molecular markers for drought tolerance and the accumulation of stem carbohydrates. Two DH populations, Westonia/Kauz (W/K) and Westonia*2/Janz (W/J), were studied in natural or irrigated (control) conditions relative to a rainout shelter (drought) conditions in the field over two years. Samples for stem carbohydrate analysis were collected at anthesis. At maturity, mainstem heads and the remaining tiller heads were harvested for comparison of grain yield between control and drought treatments. The analysis of grain yield data shows a good variation within the populations with a genetic diversity for grain yield of about 3-fold and 5-fold variation over two years under drought conditions. Transgressive segregation was observed for the grain yield in both populations. There were 39 and 8 lines producing higher grain yield than highest yielding commercial variety in W/K and W/J populations, respectively. Stem carbohydrate concentrations at anthesis varied 2.5 fold with concentrations ranging from 200 to 500 mg per g stem dry weight, i.e. 20-50% dry weight. For quantitative trait loci analysis of terminal drought, genetic maps were constructed for W/J and W/K populations using 243 and 469 markers, respectively. Joint analysis of marker and trait data revealed multiple QTLs on various chromosomes for grain yield, WSC content and concentrations under water stress in both populations. Implications of the results to marker-assisted breeding will also be discussed.

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P 5.11 - Metabolic profiling of diverse maize inbred lines under drought stress Chen X.1(xi.chen@syngenta.com), Zinselmeier C.2, Guo L.N.3, Chaulk-Grace C.4, Weiland A.4,

Portwood D.5, Seymour M.5

1 Syngenta Biotechnology Inc., Durham, NC 27709, USA; 2 Syngenta Seeds, Slater, IA 50244, USA; 3 Metabolon Inc., Durham, NC 27713, USA; 4 Syngenta Seeds, LaSalle, CO 80645, USA; 5 Syngenta Jealotts Hill Int. Research Center, Berkshire RG42 6EY, UK. Water stress, as other environmental stresses, induces numerous metabolite changes in plants. In order to identify key metabolites as molecular signatures of drought response, six diverse maize inbred lines were selected for global metabolic profiling analysis. The selected lines were replicated four times in each of two water treatments in the field (pre-flowering drought stress and a fully irrigated control treatment). Leaf tissue was collected within a one hour window during mid-day and coincided with peak drought stress. A total of 694 metabolites were detected, including 130 corresponding to chemicals with known structures. Drought stress significantly altered 13%-29% of leaf metabolites in six inbred lines. Metabolite abundance also showed significant difference among the tested genotypes regardless of water treatment. Linear discriminate analysis based on overall metabolic expression was able to differentiate the six genotypes examined and the two water treatments. In summary, this experiment has demonstrated that metabolic profiling can be used to identify metabolites and pathways involved in plant stress response.

P 5.12 - Optimising wheat root adaptation for water-limited cropping environments. Christopher J.T.1(jack.christopher@dpi.qld.gov.au), Manschadi A.M.2, Hammer G.L.3, Borrell A.K.4

1 QPI & F LRC, P.O. Box 2282, Toowoomba, Q 4350, Australia; 2 Center for Development Research (ZEF), University of Bonn, Walter-Flex Str. 3 53113 Bonn, Germany;

3 University of Queensland, Brisbane, Q 4072, Australia;

4 QPI & F HRS, 604 Yangan Road, Warwick, Q 4370, Australia. Optimising crop root systems is crucial for maximising productivity in water-limited environments. However, gains in root adaptation have been relatively slow because of the inherent difficulties in studying roots. By studying a wheat genotype which is known to have superior adaptation in the target environments, we identified root characteristics leading to improved adaptation. Intensive field phenotyping combined with root observation chambers were used to study root systems from seedlings to mature plants. This strategy has enabled the identification of root differences that would not be observable in any one system alone. The CIMMYT wheat SeriM82 exhibits higher yield and a stay-green phenotype by maintaining green leaf area longer during the grain filling period compared with Hartog, a current cultivar in the sub-tropical Australian northern grains region. Field experiments indicated that this phenotype is dependant on the presence of deep stored soil moisture. We, therefore, tested for differences in root traits and soil moisture extraction between SeriM82 and Hartog. In large soil-filled chambers, SeriM82 had a narrower mature root system and extracted more soil moisture per soil volume, particularly from depth, late in the growing season when marginal WUE is high. In small gel-filled chambers, SeriM82 exhibited a more vertical seedling seminal root angle, indicating that seminal root angle is closely related to the vertical root distribution of mature plants. Gel-filled chambers provided a rapid and effective method of screening for seminal root angle that is suitable for genetic mapping studies. Computer simulation studies indicated that a genotype able to extract small amounts of extra soil moisture from deep in the profile late in the season would exhibit improved productivity in almost all seasons over a number of representative sites in the target region.

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We now aim to use a SeriM82 x Hartog mapping population to identify the genetic regions controlling the favourable root angle trait. Further field experiments will also be conducted to determine the proportion of the yield advantage of SeriM82 which can be explained by the favourable root characteristics. Our results demonstrate the potential of integrating a wide range of techniques from field experiments to root observation chambers, computer simulation and molecular marker technology to increase the rate of crop improvement for root adaptation.

P 5.13 - Development and implementation of high-throughput EST-derived SNP genotyping and construction of a consensus genetic linkage map in cowpea [Vigna unguiculata (L) Walp.] Diop N.N.1 (ndiop@ucr.edu), Muchero W.1, Bhat P1, Fenton R.D.1, Pottorff M1, Wanamaker S.1, Hearne S.J.2, Cisse N.3, Fatokun C.2, Roberts P.A.1, Ehlers J.D.1, Close T.J.1 1 University of California, Riverside, California 92521, USA; 2 International Institute of Tropical Agriculture; 3Institut Sénégalais de Recherches Agricoles, Bambey,

Senegal. Cowpea (2n=2x=22) is an important leguminous dry grain, fodder and horticultural crop widely grown in the Savanna and Sahelian zones of West and Central Africa and to a lesser extent in East and South Africa, South America, India, and North America. Relatively little investment has been directed to understanding the genetic basis of traits conferring this species' exceptional adaptation to environmental stresses. Single nucleotide polymorphisms (SNPs) are valuable genetic markers for genetic linkage maps because very accurate high-throughput systems have been developed for their assay, and because highly polymorphic marker sets can easily be identified that work across broad sets of germplasm. We have developed such system by producing an assembly of 183, 118 cowpea ESTs from 17 diverse cowpea genotypes yielding approximately 10,000 high confidence SNPs. A total of 1,536 SNPs were chosen to design an Illumina GoldenGate genotyping assay. Six advanced RIL populations comprising a total of 760 RILs were genotyped to produce a consensus genetic linkage map universally applicable to all of these RILs. Approximately 90% of the SNPs (1370) were technically successful, among which 928 were mapped in at least one of the 6 RIL populations. The consensus map spans 680 cM portioned into 11 linkage groups for an average density of one marker per 0.73 cM. Comparison of this cowpea genetic map to the reference legume soybean (Glycine max) revealed extensive macrosynteny and highlighted regions of soybean genome duplication. Such maps provide a valuable framework for QTL identification, map based cloning, assessments of genetic diversity, association and comparative genetic investigations, and for applied breeding in molecular marker assisted selection schemes. In addition, because of its adaptation to drought and heat, cowpea can serve as an important model species for crop adaptation to abiotic stress for other related grain legumes. The aggregate EST, SNP, genetic map, and synteny information is included in a publicly available browser called HarvEST: Cowpea, which can be downloaded as a Windows software from http://harvest.ucr.edu.

P 5.14 - Phenotyping groundnut reference collection for drought related traits. Falalou H. (f.hamidou@cgiar.org) Regional Scientist (Physiologist), ICRISAT-Niamey, BP 12404 Niamey, Niger. Groundnut is grown under rainfed conditions and suffers from both intermittent and terminal drought stress, thus incurring major yield losses. Cultivars that have traits associated with drought tolerance are better endowed to achieve high yields under water deficit conditions. Thus, there is a great need to evaluate a large collection of groundnut for drought related traits, which would contribute to develop high yielding varieties under water deficit. Two hundred sixty eight (268) accession of the groundnut reference collection along with 9 local varieties were evaluated under different Vapor Pressure Deficit (VPD) and drought conditions in field and potted experiments s at ICRISAT-Niamey in Niger. The objective was to characterize the diversity, identify sources of drought tolerance and traits putatively related to better adaptation to intermittent drought. The field and pot experiments were conducted during the post-rainy rainy season (September-Nov 2008)- and the VPDmax was 2.8kpa. These experiments were repeated in the dry season with VPDmax of 5.0 kpa. Transpiration efficiency (TE), shoot water

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content (SWC), specific leaf weight (SLW), yield (Yt) and harvest index (HI) under water strees were measured. In the potted experiment, there was a wide range of variation for TE and SWC among the accession. Fleur11, a popular variety in West Africa, appeared among the top ten genotypes with high TE. Transpiration efficiency ranged from 0.5 to 4.7 g·kg-1 under VPD 2.8 kpa and from 0.45 to 3 under VPD 5 kpa. Genotype ICG 1519 showed high TE irrespective of VPD. Genotypic variation for SWC revealed that genotype 11-90 13 maintained high WC (35%) under water stress during 3 weeks. In the field experiment, significant (P =0.0001) effect of water stress and differences among the accessions were observed with regard to SLW, Yt and HI. Yield reduction under stress ranged from as high 80% to 25%. High HI and TE were observed on accessions ICGV 02022, Fleur 11, ICG 1519, ICG 1137 and ICG 10566 under drought conditions in both experiments. These accessions could be promising genotypes for improving drought adaptation in groundnut.

P 5.15 - Meta-analysis of constitutive and adaptive QTL for drought tolerance in maize Hao Z.F., Li X.H. (lixh2008caas@yahoo.cn), Liu X.L., Xie C.X., Li M.S., Zhang D.G., Zhang S.H. Institute of Crop Science, Chinese Academy of Agricultural Sciences, National Key Facilities for Crop Genetic Resources and Improvement, Beijing 100081, China. The response of plants to drought stress is very complex and involves expression of a lot of genes and pathways for diverse mechanisms and interactions with environments. Many quantitative trait locus (QTL) mapping experiments have given heterogeneous results due to use of different genotypes and populations tested in various environments. Our purpose was to identify some important constitutive and adaptive QTL using meta-analysis; and then to find specific genes and their families for speculating on drought tolerance networks. Identified neighboring markers should be useful for marker-assisted selection (MAS). A total of 239 QTL detected under water-stressed conditions and 160 detected under control conditions from 12 populations tested in 22 experiments were compiled and compared, resulting in identification of 39 consensus QTL under water stress, and 36 under control conditions. Of them, 32 consensus QTL were supposed to be adaptive QTL that induced by specific environment factors, while others were consensus constitutive QTL. The consensus QTL on chromosomes 1, 2, 3, 5, 6 and 9 were shared and could be identified under multiple individual environments, most of which were related to traits of high phenotypic variance. Moreover, 48 candidate genes related to stress tolerance were located in silico in these identified consensus QTL regions, which will facilitate the construction of QTL networks and understanding of the mechanisms related to drought tolerance, and thus the development of strategies for MAS.

P 5.16 - Linkage and linkage disequilibrium mapping of drought tolerance through chip-based single nucleotide polymorphism genotyping in maize Hao Z.F.1,2, Li X.H.2, Xie C.X.2, Lu Y.L.1,3, Li M.S.2, Zhang D.G.2, Zhang S.H.2, Yan J.B.1, Xu Y.B.1(y.xu@cgiar.org)

1Genetic Resource Program, International Maize and Wheat Improvement Center (CIMMYT), Km 45, Carretera, Mexico-Veracruz, El Batan, Texcoco, Mexico;

2Institute of Crop Science, Chinese Academy of Agricultural Sciences, National Key Facilities for Crop Genetic Resources and Improvement, Beijing 100081, China;

3Maize Research Institute, Sichuan Agricultural University, Sichuan 625014, China. Single nucleotide polymorphisms (SNPs) as a new type of molecular markers show great potentiality for dissecting genetic variation of complex traits such as drought tolerance. In this study, 405 lines from four recombinant inbred line (RIL) populations and 106 lines from 38 backcrossed introgression line (IL) sets were genotyped with Illumina GoldenGate assay containing 1536 SNPs. A total of 1164 informative SNPs were mapped using the four RIL populations, of which 190 SNPs were newly mapped to the nested association mapping map. Average distances between two adjacent SNPs in the four-RIL integrated linkage map were narrowed down to 1.25cM. For IL sets, a relatively higher genetic diversity was identified with an average polymorphic information content value of 0.27 for 924 polymorphic SNPs, and linkage disequilibrium (LD) was detected for 2402 SNP pairwise comparisons (r2 ≥ 0.5). By UPGMA, the 106 ILs were classified into five subgroups, which were consistent with

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their recurrent parent origins. To establish marker-trait association for drought tolerance, linkage- and LD-based mappings were done with 220 RILs from three populations and the 106 ILs, respectively. A total of 30 morpho-physiological traits and yield components related to drought tolerance were scored under both water-stressed and well-water regimes for all the tested RILs and ILs by аlpha-lattice design. By linkage mapping, a total of 179 quantitative trait loci were identified by composite interval mapping, explaining an average of 20.1% of the phenotypic variance. By LD mapping with population structure considered, 46 marker-trait associations were identified using a general linear model. Two candidate genes for drought tolerance inferred from two SNPs on chromosomes 1 and 10 were shared by both mapping methods. The results provide useful information for genetic dissection of drought tolerance in maize.

P 5.17 - Correlation analysis and QTL identification for some photosynthetic factors in rice under drought stress and well-watered conditions Hu S.P.1, 2, Liu H.Y.2, Zou G.H.2, Liu G.L.2, Mei H.W.2, Yu X.Q.2, Li J.2, Luo L.J.2 (lijun@sagc.org.cn)

1College of Resource and Environmental Science, Jishou university, Hunan 416000, China; 2 Shanghai Agrobiological Gene Center, Shanghai 201106, China. Photosynthetic rate (PR) and chlorophyll content (CC) are important factors in photosynthetic physiology and high photosynthetic efficiency breeding in rice. In recent times, drought or water stress has become one of the most important limiting factors for rice production. To explore the relevant molecular genetic mechanisms of PR and CC under water stress condition, we conducted a series of relational experiments using a population of recombinant inbred lines (RILs) (Zhenshan97B × IRAT109). We found a significant correlation between CC and PR (R=0.19**) in well-watered condition, but no significant correlation during water stress (r=0.08). We detected 13 main quantitative trait loci (QTLs) located on chromosomes 1, 2, 3, 4, 5, 6, and 10 that were associated with CC, including 6 QTLs located on chromosomes 1, 2, 3, 4, and 5 in water stress condition, and 7 QTLs located on chromosomes 2, 3, 4, 6, and 10 in well-watered condition. These QTLs explained 47.39% of phenotypic variation in water stress condition and 56.19% in well-watered condition. We detected four main QTLs associated with PR; three of them (qPR2, qPR10, qPR11) were located on chromosomes 2, 10, and 11 during water stress condition, and one (qPR10) was located on chromosome 10 in well-watered condition. These QTLs explained 34.37% and 18.41% of the phenotypic variation in water stress and well-watered conditions, respectively. Only one QTL for PR (qPR10) was detected in both conditions. Furthermore, a total of 16 pairs of epistatic loci for CC were detected, and were mapped to all chromosomes except Chromosome 10. Four pairs were found in water stress condition and explained 18.57% of phenotypic variation. Twelve pairs were detected in well-watered condition and accounted for 38.49% of phenotypic variation. In total, we detected 28 pairs of epistatic loci for PR located on all 12 chromosomes. Of these, 15 pairs were found in water stress condition and accounted for 46.80% of the phenotypic variation, and 13 pairs were detected in well-watered condition and explained 54.71% of the phenotypic variation. Thus the CC was largely controlled by the main QTLs, and PR was mainly controlled by epistatic QTL pairs. These QTLs and epistatic loci can help us understand the molecular genetic mechanisms of photosynthesis in rice, and will also be useful to improve the photosynthetic capacity of rice and rice yield using marker-assisted approaches.

P 5.18 - Association analysis of seedling biomass and plant height in historical wheat collection Zhang J.A.1,2, Wei T.M.1,3, Liu G.R.2, Min D.H.3, Jing R.L.1(jingrl@caas.net.cn) 1 Key Laboratory of Crop Germplasm and Biotechnology, Ministry of Agriculture, Institute of Crop

Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; 2 College of Agronomy, Agricultural University of Hebei, Baoding 071000, Hebei, China; 3 College of Agronomy, Northwest A & F University, Yangling 712100, Shaanxi, China. Wheat (Triticum aestivum L.) is the staple food crop in China, but frequently suffers drought stress during growing season. One of the efficient approaches responding drought is to improve the drought tolerance (DT) of wheat using appropriate gene resources. Association mapping is an effective method to identify excellent target alleles in

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collections based on the linkage disequilibrium (LD). In this study, 155 historical accessions collected from China were evaluated for their plant height and seedling biomass, which was related to the early vigor under both water regimes well-watered and drought stress. A total of 55 SSR markers were used to identify genotypes. All markers were selected from large effect QTLs and QTL clusters which were identified by our lab, and distribute on each chromosomes. The allele information was estimated using Power-Marker V3.25, and association of marker with trait was analyzed with a general linear model (GLM) of Tassel. The results showed that total of 483 alleles were detected among 155 accessions. The alleles varied from 2 to 38, with an average of 9.66 alleles per locus. The polymorphism information content (PIC) varied from 0.129 to 0.932. An average PIC of markers was 0.592 (range of 0.129-0.932). A total of 16 significant marker-trait associations were identified from 13 SSR markers (P<0.01). Among them, WMC112, WMC311, WMC349 and WMC727 were significantly associated with plant height (P<0.001), Xgwm82, Xgwm6, Xgwm297 and Xgwm193 are strongly associated with seedling biomass under drought stress (P<0.001). These markers may play an important role in molecular breeding for improvement of wheat production under drought. Validation of the excellent alleles is in plan.

P 5.19 - Phenotypic and genotypic analysis of drought-resistance traits in CT9993/IR62266 for development of rice cultivars adapted to rainfed environments Kamoshita A.1 (akamoshita@anesc.u-tokyo.ac.jp), Babu R.C.2, Boopathi N.M.2, Fukai S.3

1 Asian Natural Environmental Science Center, University of Tokyo, 1-1-1 Midoricho Nishitokyo,

188-0002, Japan; 2 Department of Plant Molecular Biology and Biotechnology, Center for Plant Molecular Biology, Tamil

Nadu Agricultural University, Coimbatore-641 003, India; 3 University of Queensland, School of Land, Crop and Food Sciences, Queensland, 4072, Australia. This paper reviews drought-resistance traits in rice and their quantitative trait loci (QTLs), with emphasis on CT9993/IR62266, one of the most widely studied mapping populations, and suggests ways to develop cultivars that will perform well in drought-prone environments. Resistance traits differ under different types of drought (e.g., terminal drought, vegetative stage drought, and intermittent drought), but genotypic responses that contribute to drought avoidance (e.g., deep and thick roots and conservative water use by moderate plant size) and maintain higher plant water status are often found to be more important for higher yield under stress than are tolerance mechanisms. In our analysis of 15 mapping populations that have been evaluated in drought-resistance studies, with emphasis on the CT9993/IR62266 population, four key genomic regions on chromosomes 1, 4, 8, and 9 were identified on which are co-located a number of QTLs for traits considered to be directly or indirectly responsible for grain yield under stress. QTLs for avoidance traits (e.g., deep roots) and plant type traits (e.g., plant height) had higher R2 values than QTLs for tolerance traits (e.g., osmotic adjustment, membrane stability), and were identified across different populations under both well-watered and stress conditions. The QTLs for root traits and plant type traits, together with QTLs for plant water status, were more often co-located with grain yield or yield components under stress. Although it is unlikely that a single trait will improve rice resistance to different types of drought, selection of some of the QTL clusters containing multiple drought resistance traits may be promising. In addition to selecting for specific traits or specific genomic regions, screening under managed drought conditions (i.e. dry season trials, delayed planting in the wet season, use of high toposequence locations, drainage, raised beds, and large-scale rainout shelters) on the basis of yield itself, partly assisted by selection for indicator traits such as low leaf rolling score, low spikelet sterility, and high drought response index (DRI), with their moderate to high degrees of heritability, shows promise. The current limitations of routine use of QTLs in marker-assisted selection (MAS) and transgenic rice engineered for enhanced expression of induced traits for drought tolerance will be also discussed.

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P 5.20 - Pearl millet genotypes differing for a terminal drought tolerance QTL contrast for traits related to the control of leaf water loss Kholová J., Vadez V.( V.VADEZ@CGIAR.ORG), Kakkera A., Hash C.T., Yadav R., Kočová M. International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru 502 325, India. This paper assess whether pearl millet contrasting for terminal drought tolerance, based on yield differences in the field, vary for physiological traits related to the control of leaf water loss. Two pearl millet parental genotypes differing in terminal drought tolerance, i.e. PRLT-2/89-33 (tolerant and QTL donor parent) and H77/833-2 (sensitive), and several near-isogenic lines (NILs), introgressed with the QTL in the background of sensitive H77/833-2 (BC4F2) were tested. We found that the transpiration rate (TR [g cm-2 d-1]) was lower in the tolerant parent and in the NILs than in H77/833-2. In addition, we found that although there were no differences in stomata number between the parents, the ABA content in the leaves of well-watered PRLT-2/89-33 and NILs was higher than in H77/833-2. Although ABA seemed to be closely related with the differences in TR, a defoliation experiment showed that a 50% decrease in leaf area rapidly increased (<1 h) TR in all genotypes, suggesting that hydraulic signals were likely to be involved in this rapid TR response. We also found that the TR response to an increasing vapor pressure deficit (VPD) was linear up until about 2.0 kPa in all genotypes. Above that threshold, transpiration kept on increasing linearly in H77/833-2 whereas there was a clear slow down in the transpiration response of tolerant parent and NILs, also suggesting the existence of hydraulic signal to explain such a rapid TR response. Besides, TR was examined in 106 recombinant inbred lines (RILs) derived from the cross between PRLT-2/89-33 and H77/833-2 and showed a good segregation pattern with both parents at each end of the distribution. We propose that a lower TR and TR response to varying VPD found in tolerant genotypes may help conserving soil water under well-watered conditions, leaving water available for grain filling. We tested this hypothesis by assessing the patterns of water extraction in lysimeters (2.0 m cylinders, 25 cm diameter) under terminal drought conditions. Overall the total water extracted from the tubes hardly differed between tolerant and sensitive lines. By contrast, tolerant and sensitive lines differed in their kinetics of water extraction. Tolerant lines sustained substantial water uptake in the late stages of terminal stress as opposed to sensitive lines, which took up more water before and during anthesis. Data suggest that indeed, tolerant lines appear to maintain water extraction for longer periods of time under terminal stress.

P 5.21 - Genomic characterization of drought related traits in spring wheat Kumar S.1, 2(sundeepk@ksu.edu), Sehgal S.K.1, Kumar U.3, Prasad P.V.V.4, Joshi A.K.5, Gill B.S.1 1 Dep. of Plant Pathology, Kansas State Univ., Manhattan, KS 66506, USA; 2 Department of MBGE, Sardar Vallabh Bhai Patel University of Agriculture & Technology, Modi-

puram, Meerut- 250 110, India; 3 Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466 Gatersleben,

Germany; 4 Dep. of Agronomy, Kansas State Univ., Manhattan, KS 66506, USA; 5 Regional CIMMYT Office South Asia, P.O. Box 5186, Bhadrakali, Kathmandu, Nepal. In last few years, world climatic conditions have been drastically changed. Most part of the world is under low water availability especially arid and semi-arid regions. Limited number of drought tolerant varieties and non-availability of markers for drought tolerance gene(s) make the breeding for drought tolerance a very difficult task. It is therefore necessary to appraise the work on QTL mapping for traits linked to drought tolerance. An inter-varietal mapping population in the form of recombinant inbred lines (RILs) developed from a cross between ‘C-306’ (a drought tolerant cultivar) and 'HUW-206' (a drought susceptible cultivar) was used for the identification of QTLs controlling agronomic (yield and yield attributing traits) and physiological traits (thylakoid membrane stability, chlorophyll content and canopy temperature depression) under water stressed condition. The 117 single seed descent (SSD) derived F5, F6-7 lines of ‘C-306’ × ‘HUW-206’ were evaluated for traits associated with drought tolerance for three successive experiments under well watered and water stressed conditions in green

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house at Kansas (USA). The RILs were characterized for above said agronomic and physiological traits in randomized design with three replications in each experiment. Thylakoid membrane stability and chlorophyll content showed high Pearson correlation coefficient (0.95 at 0.01%) to each other were also found positively correlated with yield per plant (0.52 and 0.51 at 0.01% respectively). To ascertain trait responses towards yield per plant, principal component analysis (PCA) was performed on these traits. The first three PC accounted for 98.5% of total variation for drought tolerance among the RILs. With respect to yield attributing traits, PC1 had a high positive correlation with thylakoid membrane stability and chlorophyll content, PC3 had the highest positive correlation with leaf temperature and PC4 had positive correlation with chlorophyll content. To identify genomic regions for traits contributing to drought tolerance, 860 genomic micro-satellite markers covering the entire genome were screened for polymorphism between parents. Out of these, 140 (16%) simple sequence repeat (SSR) markers were polymorphic on 4.0% agarose gel, were used for genotyping RILs. The genomic regions contributing towards drought tolerance were identified and results would be presented.

P 5.22 - Use of TILLING and genomic mapping tools approach in durum wheat for the improvement of yield stability under drought stress in arid and semi-arid regions Labhilili M.1(m_labhilili@yahoo.fr), Fatiha B.1, Ouabboa H.2, Parry M.A.J.3, Madgwick P.J.3, Baudo M.3, Meryem E.4 , Moufkarin N.5, Karama I.6, Hamada W.7, Al-Yasin A.8 , Tuberosa R.9, Bort J.10, Araus J.L.10, Slafer G.11

1 INRA, BP 415 , Boulevard de la Victoire, U.R. de Biotechnologie, Rabat, Morocco; 2 INRA, B.P.589, CRRA , Settat, Morocco UK; 3 Centre for Crop Genetics, Department of Plant Science, Rothamsted Research, Harpenden, Herts AL5

2JQ. UK; 4 Faculty of science of Mohamadia; 5 Faculty of science of Meknès; 6 Faculty of science of Marrakech; 7 INAT, 43 Avenue Charles Nicolle, Cite Mahrajene Tunis, Tunisie; 8 NCARTE, P.O. Box 639 Baqa 19381, Amman, Jordan; 9 Department of Agroenvironmental Science and Technology (DiSTA), University of Bologna; 10 Facultat de Biologia, Universitat de Barcelona; 11 University of Lleida. In Morocco, cereals are the most cultivated crop. Indeed the area of these crops takes up than 63% (5.6 million hectares) of the agricultural useful area. Durum wheat is taken the second place after breed wheat. The traditional methods of selection provided to the farmers broad range of variety, thus carrying out profits of output of 30%. In spite of these improvements, the National production doesn’t cover the needs of the population. In fact, drought is the major problem that affects production of wheat. Since Durum wheat has limited genetic diversity, EMS mutagenesis was used to generate a novel genetic variation in elite Durum lines. More than 6000 lines was produced and drought adapted lines are under selection. To understand molecular way participating in drought tolerant mechanisms, new technique as TILLING (Targeting Induced Local Lesions IN Genomes) which uses PCR to identify individuals lines containing mutant lesions generated by EMS from a large population of mutagenised lines was developed. Specific primers are used to amplify a region of the gene of interest from DNA isolated from pools of several individual lines. Dehydrin gene and others are under investigation. For the identification of QTLs linked to droughts tolerance, durum linkage map was developed and physiological and agronomic evaluation are ongoing.

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P 5.23 - Validation of a QTL for root and agronomic traits in maize as evaluated by Near Isogenic Lines (NILs) and their crosses at two water regimes Landi P., Ferri M., Bellotti M., Giuliani S., Salvi S., Tuberosa R., Sanguineti M.C. (maria.sanguineti@unibo.it) Department of Agroenvironmental Sciences and Technologies, University of Bologna, Viale Fanin 44, 40127, Bologna, Italy. In a previous study on a maize population of F2:3 families derived from Lo1016 × Lo964, we detected one QTL in bin 1.06 affecting root and agronomic traits for plants grown at well-watered (WW) and water-stressed conditions (WS). Starting from two F3:4 families, we developed two pairs of NILs (as F7:8) at this QTL. Objective of this study was to evaluate the QTL effects across different irrigation treatments and genetic backgrounds. We tested NILs per se, at WS, and their crosses with the two parental inbreds, at WW and WS. As to NILs per se, the interaction QTL × family was negligible for most traits. The QTL additive effect across families was significant for number of leaves/plant, growth rate, plant height, kernel moisture, kernel weight, and root clump weight. As to NILs’ crosses, the water-stress treatment affected negatively several traits (-21% for grain yield). The interactions QTL × irrigation treatment and QTL × family were negligible for most traits, thus suggesting that the QTL acts mainly constitutively, rather than being water-stress responsive (at least within the range of water stresses investigated), and that its effect is not much influenced by epistatic interactions. The additive effect at the QTL across irrigation treatments and families was significant for number of leaves/plant, growth rate, plant height, stalk diameter, kernel moisture, grain yield and its components; such effects were consistent one another (i.e., of the same sign) and consistent with the effects of NILs per se, thus suggesting a pleiotropic control of the QTL on overall plant size and vigour.

P 5.24 - Application of marker-assisted selection for drought tolerance in Rice ( Oryza sativa L.) Lang N.T. (ntlang@hcm.vnn.vn), Buu B.C. Genetic and Plant breeding division , Cuulong Delta Rice Research Institute , Vietnam. Drought stress is a major constraint across many rice – ecosystems worldwide, because of the high sensitivity of modern rice varieties rice varieties to drought. This forces farmers to continue to grow their traditional landraces with low yield and low grain quality. In Vietnam, drought affected areas covers about 1 million ha across the countries, and their some problems for resource poor farmers who depend on rice production for their livelihoods. This research to take advantage of modern breeding tools, such as marker–assisted selection, to development high yielding drought tolerance rice varieties adapted to the conditions of lowland and up lands rice. New drought tolerant rice varieties also adapted to the Mekong delta region are being developed using different approaches, including conventional breeding, anther culture, soma clonal variants, mutants as well as molecular breeding. In the later approach, we are developing mapping populations to identify major QTLs associated with drought tolerance, fine-mapping major QTLs and develop a marker assisted system to speed up their introgression into popular varieties and elite breeding lines. Some varieties such as Om 6162, OM 6840, OM 4495, Om 7347. were developed that can yield 4-5 ton ha-1 under drought stress of 30 days, earliness, quality parameters and are being out-scaled for farmers.

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P 5.25 - An intensive study of a drought tolerance QTL interval in rice: expression profile analysis and drought tolerance gene mining Liu H.Y. (lhy@sagc.org.cn), Yu S.W., Luo L.J. Shanghai Agrobiological Gene Center, 2901 Beidi Road, Shanghai 201106, China. Several important drought related QTL intervals on chromosome 1, 2, 4, 8 and 9 in rice were revealed based a great deal of drought resistance mapping researches. These intervals holding QTLs related to many drought related traits. We selected the QTL interval on chromosome 4 as the target region of this research. Our former mapping results indicated that this region contained QTLs related to canopy temperature, spikelet number per panicle, panicle neck diameter. And some root related traits under drought condition were reported to be located in this region. The purpose of this research is to find out the drought related genes between the target region, to reveal the expression profile of those genes and to select the putative candidate genes with high drought tolerance ability. According to our mapping results, the target QTL interval is located between marker RM241 and RM349, which is 5.64Mb and contained 862 putative genes. Through Plant QTL-GE web search system, 206 drought related ESTs between the interval were found. And thereinto, 167 ESTs are nonredundant. We finally cloned 128 ESTs from IRAT109 seedling under drought condition. The expression profile of all 128 ESTs were analysed by semi-quantitative PCR. For seedling samples, leaf and root were sampled after 30 min, 3 hours, 8hours and 20hours dehydration. For plants at reproductive stage, leaf and panicle were sampled after 2 and 4 weeks drought. The results indicated that: 1) The number of up expressed ESTs are more than that of down expressed ESTs. And the number of ESTs response to drought in root are more than that in leaf and panicle. 2) There are some ESTs keeping on up or down expression in deferent stage, tissue and drought stress intensity. GO analysis shows that those lasting up expressed ESTs are mainly involved in signal transduction and osmotic solute synthesis. As for those keeping on down expressed ESTs, they are mainly involved in protein phosphorylation and protein synthesis. 3) GO analysis shows that the number of up or down expressed ESTs and related GO types in early drought stress in both seedling stage and reproductive stage are more than that in the later drought stress in both stages. 4) We finally selected 12 putative candidate genes according to the expression profile analysis and the related research report.

P 5.26 - Microarray-based expression analysis of drought-stress-regulated miRNAs in Oryza sativa Liu Z.C. (lzc@sagc.org.cn) Shanghai Agrobiological Gene Center, 2901 Beidi Road, Shanghai 201106, China. Of the roles of miRNAs in regulating plant growth and development processes, the most currently proposed interesting function of miRNAs is the hypersensitive to abiotic stress and various physiological processes including nutrient deficiency in Arabidopsis. To better understand molecular mechanism of drought tolerance in rice, we applied microarray analysis to detect drought-stress-regulated miRNAs from tillering to inflorescence forming stage in rice. We found that A total of 30 plant miRNA were identified to be significantly down- or up-regulated under drought stress induced by water withholding in rice plant, of which 20 plant miRNA such as down-regulated miR170, miR172, miR397, miR408, miR529, miR896, miR1030, miR1035, miR1050, miR1088, miR1126 and up-regulated miR395, miR474, miR845, miR851, miR854, miR866, miR901, miR903, miR1125 were first revealed to be induced by real drought stress in plant, and 9 miRNAs (miR156, miR168, miR170, miR171, miR172, miR319, miR396, miR397, miR408) showed completely opposite expression to that in Arabidopsis. The most conserved down-regulated miRNAs were ath-miR170, miR171 family and ath-miR396, and the up-regulated miRNAs were ptc-miR474 and ath-miR854a. Analysis of qRT-PCR as well as target genes and the cis-elements in their promoter regions provide further evidence for the possible involvement of these differential miRNAs in the process of drought response and/or tolerance. The identification of differentially expressed plant miRNAs in this study, their target genes and cis-element analysis provide molecular evidence for the possible involvement of miRNAs in the process of drought response and/or tolerance in plants especially in rice.

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P 5.27 - Integrated linkage-linkage disequilibrium mapping for drought tolerance using global maize germplasm genotyped by two single nucleotide polymorphism chips Lu Y.L.1,2, Zhang Z.W.3, Hao Z.F.1,4, Vivek B.S.5, Magorokosho C.6, Mugo S.7, Makumbi D.7, Taba S.1, Shah T.1, Yan J.B.1, Li J.S.8, Zhang S.H.4, Rong T.Z.2, Buckler E.3, Crouch J.H.1, Xu Y.B.1(y.xu@cgiar.org) 1 Genetic Resource Program, International Maize and Wheat Improvement Center (CIMMYT), Km 45, Carretera, Mexico-Veracruz, El Batan, Texcoco, Mexico;

2 Maize Research Institute, Sichuan Agricultural University, Yaan, Sichuan 625014, China; 3 Institute for Genetic Diversity, Cornell University, Ithaca, New York, USA; 4 Institute of Crop Science, Chinese Academy of Agricultural Sciences, National Key Facilities for Crop Genetic Resources and Improvement, Beijing 100081, China;

5 CIMMYT Int., C/o ICRISAT, Patancheru-502324, Greater Hyderabad, (A.P.), INDIA; 6 CIMMYT, 12.5 Km peg Mazowe Road, P.O. Box MP163, Mount Pleasant, Harare, Zimbabwe; 7 CIMMYT, PO Box 1041, Village Market-00621, Nairobi, Kenya; 8 National Maize Improvement Center of China, China Agricultural University, Beijing 100094, China. Drought is the most significant environment stress in agriculture worldwide and the first constraint to maize production. Improving yield under drought stress is a major goal in maize breeding. In this study, 535 temperate and tropical maize germplasm were phenotyped at vegetative and reproductive stages under well-watered and water-stressed regimes for 63 traits representing different selection criteria for drought tolerance, including biomass as measured as the normalized difference vegetation index (NDVI) with a portable spectroradiometer (GreenSeeker), anthesis-silking interval, leaf senescence, chlorophyll content, root capacitance, final grain yield and drought tolerance indix (DTI) (Xu et al, this conference). All tested lines were genotyped using two Illumina GoldenGate assay chips containing 3072 SNP makers that were designed from random sequences and the candidate genes related to drought tolerance. A total of 2139 informative SNPs were selected with high quality for population structure analysis and integrated linkage-linkage disequilibrium (LD) mapping. Seven major clusters identified by principal component (PC) analysis were consistent with geographic origins and pedigree information. Preliminary results from LD mapping using a general liner model combining PC-matrix identified 39 marker-trait associations involving 18 markers and 17 traits (P-marker value <10-8). Twelve of the 18 SNPs could be traced back to the genes that may relate to maize drought tolerance, such as those for starch synthase, sucrose synthase, terminal acidic SANT 1, phosphatidylserine decarboxylase, and phytochrome A2. Ten SNPs were co-associated with multiple traits that were phenotypically correlated, e.g, SNP PHM5716.60 on chromosome 3 associated with five correlated traits (ear number, ear weight, ear length, grain weight and flowing time). Nine traits were found each to be associated with more than two markers. For example, there were eight, five and two markers associated with ear weight, grain weight, and female flowering time, respectively. The average total variation explained by a marker is 7.0%, with the highest for SNP PZA03134.1 (18.1%) for DTI. Integrated linkage-LD mapping is underway and the results will be compared with those obtained by linkage-based mapping (Hao et al, this conference) and QTL reported in previous reports. The candidate gene-based SNP genotyping combined with the integrated linkage-LD mapping provides a powerful strategy for identifying genes associated with drought tolerance in maize.

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P 5.28 - Transgenic rapeseed (Brassica napus) expressing AtDREB1B show enhanced cold tolerance Mafi-Moghaddam S. (smafi@can.ut.ac.ir), Soltani A., Yazdi-Samadi B., Mohammadi V., Alizadeh H. Department of Agronomy and Plant Breeding, College of Agriculture, University of Tehran, Karaj, 3158777871, Iran. Plants being sessile, their growth and yield are strongly influenced by abiotic stress such as drought, salt content and temperature changes. Dehydration responsive elements binding proteins (DREB) are important transcription factors that induce a set of abiotic stress-related genes conferring stress endurance to plants. The DREB1/CBF subclass is involved in signal transduction pathway under low temperature. Cold stress, although seasonal, has some similarities to a drought, since as water freezes it creates concentrated solutions of solutes. It also subjects the plant to a shortage of liquid water. In order To get cold tolerance in rapeseed, DREB1B gene was overexpressed in a cultivar of rapeseed (Brassica napus) called PF7045/91. AtDREB1B construct containing AtDREB1B CDS under control of CaMV35S promoter was transferred to 7-day-old cotyledons through Agrobacterium-mediated method. The insertion, expression and copy number of the gene in T1 plants were confirmed by PCR, Reverse transcriptase PCR and southern blot, respectively. The transgenic plants overexpressing the DREB1B gene showed a remarkable increase in cold tolerance in comparison with the control ones. The results suggest that engineering stress tolerance by means of regulon genes such as DREB1B can effectively improve abiotic stress endurance in rapeseed.

P 5.29 - Cloning of CBF2 transcription factor and identification of function in soybean plants Min Q.U.1,, Li X.L.2, Zhang S.1，Xu X.L.2, Wang Q.W.2 (xxl8761@126.com) 1 Biology Department of Food Engineering College, Haerbin University of Commence, Harbin,

Heilongjiang, 150076, China; 2 Life and Environmental Science Institute, Haerbin Normal University, Harbin, Heilongjiang 150080,

China. The CBF2 gene were cloned from the Arabidopsis thaliana. The plant expression vector pBI-rd29A-CBF2 driven by rd29A promoter was constructed. The CBF2 gene was transformed into soybean via Agrobacterium-mediated transformation that infected the cotyledonary nodes and the whole plants. It had been approved that the CBF2 gene has been integrated into the genome of soybean by PCR and Southern blot. Through the physiological test of salt resistance, the relative electronic conductivity of the transformed plants plasma membrane and the control were 59.35% and 36.84% respectively under salt stress. The content of chlorophyll of the transformed plants was 2.41 times as much as that of the control. The content of proline of the transformed plants was 2.49 times as much as that of the control. Through the physiological test of drought resistance, The content of relative water of leaf, chlorophyll and praline of the transformed plants was 1.47 times, 2.23 times and 3.01times as much as that of the control. The results indicated that the expression of the CBF2 gene increased the salt and drought stress tolerance of the transgenic soybean.

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P 5.30 - Characterization of betaine aldehyde dehydrogenase loci in Arabidopsis thaliana Missihoun T.D., Kirch H.H., Bartels D. (dbartels@uni-bonn.de) Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, 53115 Bonn, Germany. Arabidopsis thaliana belongs to the plants that do not naturally accumulate the osmoprotectant glycine betaine (GB). Yet, its genome contains two genes ALDH10A8 and ALDH10A9 that code for putative betaine aldehyde dehydrogenases (BADHs). BADHs catalyse the last step of the biosynthesis of GB in plants. Here, we analysed the expression patterns of ALDH10A8 and ALDH10A9 genes under stress conditions and characterized Arabidopsis T-DNA insertion mutants for the ALDH10A8 gene (ko8). Northern blot analysis showed that none of the genes is induced upon stress treatments in wild-type seedlings and adult plants. In contrast to the wild type, ko8 plants were impaired in the germination and growth rates when sown on medium supplemented with sodium chloride. Moreover, soil-grown ko8 seedlings and 4 week-old plants proved more sensitive to salt stress than the wild type. But, no difference was observed between wild-type and ko8 plants when subjected to drought stress. Taken altogether, it appears that the ALDH10A8 gene is involved in the stress physiology of Arabidopsis, presumably in a way that is different from the GB biosynthesis. Hence, further investigations are needed to elucidate the role of the ALDH10A8 protein in the stress tolerance acquisition process.

P 5.31 - Association of SNP variation in candidate genes with drought tolerance across diverse rice germplasm Naredo M.E.B., Cairns J.E., Wang H.H., Atienza G., Sanciangco M.D., Melgar R.J.A., Kumar A., Ramaiah V., Serraj R., McNally K.L. (k.mcnally@cgiar.org) International Rice Research Institute, DAPO 7777, Metro Manila 1301, Philippines. Rice genetic resources are an important source of genes potentially useful for improvement of drought tolerance. EcoTILLING, a tool for detecting SNPs or indels in natural populations, was employed to survey variation in a panel of 1536 rice varieties representing the range of diversity conserved in the International Rice Genebank. Candidate genes related to drought tolerance were chosen using convergent evidence from annotated gene function, contrasting expression, co‐localization with QTLs for yield under drought, and information from the literature. Target genes included the AP2 domain transcription factors DREB2 and ERF4, sucrose synthase, TPP, MAPK, bZIP, and actin depolymerizing factors. Haplotype mis-match patterns were obtained by agarose-based EcoTILLING for variety contrasts to both IR 64 (indica) and Nipponbare (japonica). Representative samples were sequenced to validate and identify corresponding SNPs. Haplotypes obtained based on scores of the two contrasts were largely supported by sequence data. The population structure of the panel was determined by model-based analysis of SSR genotyping data, allowing its stratification into variety groups that were then partitioned into haplotypes. The diverse accessions were phenotyped under upland and lowland conditions for performance under drought stress. Stress was imposed at vegetative stage (upland) and reproductive stage (lowland). Large phenotypic variation was observed within each variety group for tolerance to drought stress. Several haplotypes of candidate genes were found to be associated with tolerance to drought stress. The magnitude of significant differences between haplotypes within variety groups was highest for the AP2 domain transcription factors, consistent with their potential effect on multiple drought traits. Only rare haplotypes were observed for TPP (trehalose-6-phosphate phosphatase) and the primary haplotype was shared across varietal groups, suggesting that this locus is under intense selection.

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P 5.32 - Tolerance to salt and drought stress among selected indian finger millet (Eleusine coracana L. Gaertn) cultivars Nethra N. (nethratina555@yahoo.com), Rame G. Department of Seed Science and Technology, University of Agricultural Sciences, Bangalore 560065, India. Experiments were designed to examine differences in some morpho-physiological characters among finger millet genotypes in response to salt and drought stress at germination and seedling growth stage and to determine the relationships between these characters. Twenty one finger millet (Eleusine coracana) varieties were used to study germination, early seedling growth and vigour were studied in pot grown plants under saline (NaCl) and simulated drought (PEG 6000 and Mannitol) at 0.5 MPa. An experiment for the standardization of the concentrations for 50 percent threshold limit of germination was done with different levels of concentration of NaCl and PEG 6000 solutions. 0.5 MPa concentrations were standardized for both NaCl and PEG 6000 and distilled water was used as control. The results obtained in saline and osmotic stress were parallel. However, tolerant varieties showed less decrease in germination, early seedling growth and vigour parameters when compared to control. Mean, Range and variability parameters showed significant reduction over control. The calculations of PCV and GCV showed that the impact of environment is more on seedling dry weight and seedling vigour index-II while it was minimal in case of germination percent and shoot length. The heritability estimates ranged from 34 (germination) - 75 (seedling dry weight) and 43 (root shoot ratio) - 74 (seedling vigour index-2) percent in NaCl and PEG treatments, respectively indicating high heritability for germination shoot length and root to shoot ratio. The genetic advance percent mean was 46.7 and 64 percent for seedling vigour index-II in NaCl and PEG, respectively. The correlation coefficient in salt and osmotic stress solutions showed positive correlation with root length and total seedling length and seedling dry weight with seedling vigour index-II. Among the selected varieties, Indaf-9 and PR-202 performed better than others. Finger millet seeds were more tolerant to salinity in germination than in the seedling phase. The use of isotonic PEG solutions indicated that the inhibitory influence of NaCl on finger millet was principally a specific ionic effect and only a small portion of inhibition could be attributed to osmotic effect. The significant basic information gathered in such experiments particularly on seedling growth parameters could be utilized for varietal screening and indicates that seedling vigour index-II (based on germination and seedling dry weight) is more amenable trait for selection in finger millet for abiotic stress.

P 5.33 - Integrated genetics and genomics approach to improving drought tolerance in soybean Nguyen H.T. (nguyenhenry@missouri.edu) National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA. Global climate changes impose huge challenges on worldwide crop production and this demands the requirement of directed adaptation of crop species on an unprecedented magnitude. Drought is the major abiotic stress factor affecting yield and stability of crop production. It is reported that the average yield losses are more than 40% in soybean due to drought stress. Understanding the concept and components of drought resistance is a key factor for improving drought tolerance of crops. Our long term goal is to produce drought tolerant soybean with improved productivity since it is one of the major food sources and can be used as bio-energy crop. Our research program focuses on an integrated genetics and genomics approach to dissect molecular processes from transcriptome to phenome. The root system plays a vital role in plant adaptation and productivity under water-limited environments. Deeper and proliferate root system help extract enough water under these environmental conditions. We have screened and identified soybean lines which exhibit genetic diversity in root system developmental plasticity in response to water stress, in order to enable physiological and genetic analyses of the regulatory mechanisms involved. To dissect the molecular processes associated with the root system responses under water deficit conditions, we have conducted extensive gene expression profiling utilizing microarray and deep sequencing platforms, and in-house developed unique library of transcription factor genes in soybean. Collectively, we have

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identified several root tissue specific and drought stress specific candidates including the key transcription and signaling factors. The characterization of these candidates, engineering of selected genes through translational genomics pipeline, and field testing of the transgenics are in progress. The presentation will highlight the global research strategies, collaborative networks, and key findings to date.

P 5.34 - Spatial and temporal profiling of DNA methylation induced by drought stress in rice Pan Y.J.1, Fu B.Y.1, Wang D.1, Zhu L.H.1, Li Z.K.1,2(Lizhk@caas.net.cn)

1 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/The National Key Facilities for Crop Genetic Resources and Improvement, Beijing 10008, China;

2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines. This experiment aimed at study of the relationship between DNA methylation and drought responsiveness in rice by characterizing DNA mathylation in leaves and roots at seedling stages and tillering stages under drought stress for DK106 (drought tolerance introgression line) and IR64 (recurrent parent and drought sensitive line). Methylation sensitive amplified polymorphism (MSAP) and high performance liquid chromatography (HPLC) were used to analyze the DNA methylation level in this study. The differentially methylated DNA fragments induced by drought were isolated from the polyacrylamide gel, cloned and sequenced, then the sequences were blasted at the NCBI website. Results showed that about 20% cytosine of CCGG sequences in rice genome was methylated, and the average level of methylation was increased under drought stress treatment, especially in roots; But the alterations of the DNA methylation state and level induced by drought stress were different between DK106 and IR64, and were also specific at different growth stages and in different tissues. The BLAST results of the differentially methylated DNA sequences showed that the methylation frequency was similar in coding region and non-coding region on the genome. It was revealed that the pattern of DNA methylation under drought was temporal-spatial specific and variety specific, and the change of DNA methylation was related to drought responsiveness.

P 5.35 - Prospecting soybean (Glycine Max L. Merrill) genes expressed under drought conditions Rodrigues F.A.1, Marcolino J.1, 2, Nakayama T.J.1, 2, Fuganti R.1, Engels C.1, 2, Marin S.R.R.1, Farias J.R.B.1, Neumaier N.1, Marcelino F.C.1, Binneck E.1, Abdelnoor R.V.1, Nepomuceno A.L.1

(nepo@cnpso.embrapa.br)

1Embrapa Soybean, Caixa Postal 231, CEP 86001-970 Londrina, PR, Brazil; 2Londrina State University; Londrina, PR, Brazil. The sustainable agriculture has been supported due to the development of advanced technologies. In this context, the molecular tools are very important for crop breeding, helping the improvement of germplasm for use in agriculture. Soybean (Glycine max L. Merrill) represents the major crop cultivated in the world and it is economically very important due to its use as human and animal feed. Soybean has become also an important raw material source for production of biofuels and other industrial products. Gene expression studies allow identifying new genetic variability sources, such as genes involved in stress tolerance. The information can be used in the development of molecular markers for breeding assisted selection as well as to understand the complex biochemistry pathways involved in plant stress responses. New genetic engineering strategies can be developed to improve yield and product quality of the cultivated plants in an adverse environmental condition. Thus, Suppressive Subtractive Hybridization method was used to identify differentially expressed genes in Brazilian soybean cultivars considered tolerant and sensitive to drought. Plants were grown hydroponically until V2 stage where after this period water was withheld and samples were collected by time periods of 15 min. The mRNA from roots and leaves samples were used in the synthesis of subtracted libraries enriched by PCR (Polymerase Chain Reaction). PCR products were sequencing and the bioinformatics analyses are applied to provide a collection of transcripts responsive to drought in roots and leaves of Brazilian tolerant and sensitive soybean cultivars. The in silico collection will permit to determine the induced gene expression profile in response to stress

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and it can help to establish a metabolic models for mechanisms used by these genotypes to protect themselves against the drought.

P 5.36 - QTL mapping in cotton (Gossypium hirsutum L.): chromosome 19 containing important genomic regions for stress tolerance Saeed M.1 (saeed242@hotmail.com), Guo W.Z.1, Ullah I.2, Tabbasam N.2, Zafar Y. 2, Rahman M.2, Zhang T.Z.1

1 National Key Laboratory of Crop Genetics and Germplasm Enhancement, Cotton Research Institute, Nanjing Agricultural University, Nanjing 210095, China;

2 Plant Genomics & Mol Breeding (PGMB) Lab, National Institute for Biotechnology & Genetic Engineering, Faisalabad, Pakistan.

Increasing scarcity of irrigational water is a major threat to sustainable production of cotton (Gossypium hirsutum L.). Identifying genomic regions contributing to drought tolerance will help develop cotton cultivars suitable for water-limited regions through molecular marker-assisted breeding. A molecular mapping F2 population was derived from an intraspecific cross of the drought sensitive G. hirsutum cv. FH-901 and drought tolerant G. hirsutum cv. RH-510. Field data were recorded on fiber quality (length, strength,% maturity) and physiological traits (osmotic adjustment, net assimilation rate, transpiration rate, stomatal conductance) under water-limited growth conditions. The two parents were surveyed for polymorphism using 6500 SSR primer pairs. Joinmap3.0 software was used to construct linkage map with 64 polymorphic markers. Linkage map comprised of 12 linkage groups, among them 9 found to be located on chromosomes 19, 1, 10, 18, 17, 12, 1, 14 and 20 respectively. QTL analysis was performed by composite interval mapping (CIM) using QTL Cartographer2.5 software. Fiber quality and physiological traits were influenced by 4 (length 1, fineness 2,% maturity 1) and 5 (osmotic adjustment 3, net assimilation rate 1, stomatal conductance 1) QTLs respectively. Out of these 9 QTLs for fiber quality and physiological traits, most QTLs were clustered on chr. 19. So it is suggested that chr. 19 contain important genomic regions affecting drought tolerance in cotton. In the future, research will be carried out to fine map these genomic regions to facilitate molecular breeding programs for drought tolerance.

P 5.37 - Progress towards fine-mapping of a major QTL for drought tolerance and yield in pearl millet Sehgal D.1(rsy@aber.ac.uk), Nepolean T.2, Hash T.2, Yadav R.1

1 Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Gogerd-

dan, Aberystwyth, Ceredigion, SY23 3EB, UK; 2 International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Patancheru 502324, India. A major QTL for terminal drought tolerance (DT) has been identified and validated on pearl millet LG 2 using two independent marker assisted selection programmes. The mapping interval of this DT-QTL, however, is still quite large (circa 30 cM), making precise selection for this QTL difficult in applied marker-assisted plant breeding programmes. For fine mapping of this QTL, a high resolution cross (HRC) segregating only for the DT-QTL interval has been developed from donor parent PRLT 2/89-33 in the genetic background of elite pollinator H77/833-2. A near-isogenic drought tolerant QTL introgression line, ICMR 01029 (BC4F1), was used as the starting material for developing HRC. Seven plant-by-plant crosses based on ICMR 01029 and ICMR 01004 (a downy mildew resistant derivative of H77/833-2) were produced. BC5F1 plants of each of these 7 plant-by-plant crosses were selfed to produce BC5F2 seeds. Seeds from two BC5F2 families were advanced to constitute a fine-mapping population. Around 2500 BC5F2 individuals of this fine mapping population were genotyped with 6 SSR markers covering the entire DT-QTL region on LG2 to select maximum recombinants within this region. Four hundred most informative recombinants were selected in all the probable parental combinations. These informative recombinants are being used for mapping gene-based markers, and for phenotyping yield and yield contributing traits. To develop gene-based markers such as CISPs and EST-SNPs mapping to LG2, available pearl millet ESTs are aligned with rice, maize and sorghum databases and primers are designed to amplify orthologous loci in pearl

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millet. To identify candidate genes underlying DT-QTL on LG 2, an in-silico analysis of the candidate region on LG2 is also being conducted by aligning this LG to equivalent genomic regions within Gramineae using GRAMENE portal. Pearl millet LG2 showed synteny with chromosomes 2S, 3L, 6S and 10L of rice, LG I of foxtail millet, 7H of barley and LG 10 of sorghum. In-silico analysis revealed ~200 genes associated with cellular metabolism, signal transduction and transcriptional regulation, spanning this DT-QTL region. In addition a number of genes, for instance, CBF4, DREB, EREBP, SnRK2, MAPK, SOS kinase, ERECTA, OsCDPK7, Mn-SOD, AVP1, MYB, MYC, EXP15, EXP2, EXP13, known to influence drought response in model and other crops have been identified. Orthologous sequences to these genes are being mapped on to the pearl millet genome to explore any relationship they may have to the pearl millet DT-QTL on LG2. Progress in developing and mapping of gene derived markers will be discussed in context of reducing the mapping interval of DT-QTL interval on LG 2.

P 5.38 - Phenotyping and genetic analysis of spikelet fertility and reproductive stage traits in rice under water deficit Sellamuthu R.1,2, Hong H.1, Babu R.C.2, Serraj R1 (R.Serraj@cgiar.org) 1 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines; 2 Tamil Nadu Agricultural University, Coimbatore – 641 003, India. Reproductive development is the most drought sensitive stage affecting yield stability in rainfed rice. This study was conducted to identify QTLs for traits influencing grain yield under reproductive-stage drought stress. A backcross mapping population consisting of 289 (BC1F4) lines developed from a cross between Apo (improved upland indica type) and Moroberekan (traditional upland japonica type) was used. Field phenotyping was done in dry seasons of 2007 and 2008 under well watered and reproductive-stage drought conditions. Flowering was delayed under stress by 11.5 days on average in both seasons, and grain yield was reduced by 58% and 65% under drought in 2007 and 2008, respectively across lines. Harvest index (HI), panicle length, peduncle length, spikelet fertility, pollen fertility and panicle exsertion all had significant positive correlations with grain yield. The significance of other panicle traits can be elucidated by the highly significant correlations of filled grains per panicle, panicle length, peduncle and panicle exsertion with HI. Path analysis revealed that yield under stress was directly affected by HI, dry matter yield, pollen fertility, peduncle length and panicle exsertion. A total of 125 QTLs were identified for the traits observed in both years under both well-watered and drought conditions. A region on chromosome 6 was linked to grain yield under drought in both years. This locus was also associated with several traits including days to flowering, peduncle length, panicle fertility and HI under drought. A QTL on chromosome 12 was identified under well-watered conditions both years and was also linked to total dry matter yield. This region lies very near to QTL12.1 reported for yield under drought in a Vandhana by Way Rarem cross. The yield increasing allele was contributed by the recurrent parent Apo. Additional QTLs were mapped for hundred grain weight, panicle length and plant height under drought, and were contributed by Moroberekan alleles. Overall, this study shows that the identification of genomic regions associated with reproductive-stage traits and yield components under drought, using reasonably large mapping populations and precise phenotyping will accelerate the breeding and the development of drought resistance rice cultivars.

P 5.39 - Mapping QTLs for physiological traits associated with grain yield in Indian durum wheat Shinde S.S. (satishmisra@yahoo.com), Patil R.M., Tamhankar S.A., Rao V.S., Misra S.C. Genetics and Plant Breeding Group, Plant Sciences Division, Agharkar Research Institute, G. G. Agarkar Road, Pune 411004, India. Central and peninsular regions account for nearly 1/3 of total area under wheat cultivation in India. Although having high yield potential, the productivity of this area is very low due to warmer temperature during crop growing season and inadequate availability of water for irrigation. Therefore, breeding for high yielding genotype with better water use efficiency is warranted. Several morpho-physiological traits such as carbon isotope discrimination (∆), Canopy Temperature Depression (CTD) and ash content have been identified as screening criteria for high yield under drought condition. A genetic linkage map was developed from a population of 140 RILs (F2:7) from a cross of Indian durum wheat cultivar PDW 233 and landrace Bhalegaon 4. The map comprised

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214 markers spanning a distance of 2357.9 cM forming 13 linkage groups and represented all the chromosomes except 3A. Average marker density was 11.02 cM/marker and average map length was 176.67 cM/chromosome. The map was used to locate the QTLs for grain yield (Yld), carbon isotope discrimination (∆), CTD and ash content in Indian durum wheat. For grain yield, one QTL each was detected on chromosomes 2A, 4B and 6A, while two QTLs were identified on 1B. A major QTL, QYld.macs-2A flanked by Xgpw2333 – Xcfa2099 explained around 15.51% variation in grain yield. The only significant QTL for ∆, QCid.macs-4B flanked by XRht-B1-Xgwm368 accounted for 15.9% of variation in the trait. CTD was affected by one QTL each from chromosome 2A and 6A. QCtd.macs-2A was co-located with the major QTL for grain yield, QYld.macs-2A, suggesting the association between the traits. For ash content, one QTL each was identified on chromosome 1B, 5A and 6A each, explaining 10.8% - 14.2% variation in the trait. The QTLs and their flanking markers identified in the present study may be used for tracking their flow in breeding material, which may used as better selection strategy for physiological traits associated with grain yield in durum wheat under water stress condition.

P 5.40 - Analyzing the response of rice seedling to drought stress by an integrated approach of transcript, protein and metabolite profiling Shu L.B.1, Lou Q.J.1, Luo L.J. 1, Ma C.F.2, Xu G.W.2, Ding W.1, Wu J.H.1, Mei H.W. 1

(hmei@sagc.org.cn)

1 Shanghai Agrobiological Gene Center, Shanghai 201106, China; 2 Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. Rice (Oryza sativa L.) is one of the most widely cultivated food crops throughout the world. Water deficit is an important abiotic stress limiting the growth and productivity of rice in rainfed or other drought prone areas. Drought tolerance in crops was proved to be a very complex characteristic. To obtain a better understanding of responses in rice plant to drought stress, parallel analysis of transcript, protein, and metabolite profiling was conducted leaves of rice seedlings. In a pot trial, 30-day-old rice seedlings were exposed to water deficit by withholding water for 1 day to 9 days. Leaf samples were collected from seedlings after withholding water for 3 days when leaf rolling and significant changes in soil water content, leaf water potential and proline content were observed. The transcriptome analysis based on cDNA microarray showed 4186 gene probes were difference expressed between drought stress and the control, including 1716 up- and 2470 down-regulated. Also, a total of 71 protein spots showed significant altered expression response to drought with 60 of them were successfully identified. The functional categorizing showed that the largest fraction of down-regulated proteins were mainly associated with transcription and translation. In contrast, the up-regulated were mainly associated with stress defence and redox homeostasis. To annotate five proteins with unknown function, BLASTP (www.ncbi.nlm. nih.gov/BLAST/) was used to identify highly similar homologues with known functions. The correlation of the differentially expressed proteins and their corresponding mRNA were investigated and shows high coefficients for the category of metabolism, but low values for non-metabolism categories. Metabolite profiling based on GC-MS was occupied to identify 40 different expressed metabolites. They were classified into 6 categories including amino acids, fatty acids, organic acids, sugars, sugar alcohols and others. The integrated analysis of differentially expressed mRNAs, proteins, and metabolites delivered some ideas about responses of metabolic pathways. For examples, the down-regulation of fatty acid and carbohydrate biosynthesis, and the up-regulation of glycolysis and citrate cycle (TCA cycle) were observed that strongly suggesting more energy consumption and high speed of metabolite transform in rice seedlings under drought stress. All of the six different expressed amino acids (including proline) were found to be up-regulated, showing the accumulation of free amino acids with parts of them serving as osmotic agents. In conclusion, parallel analysis of multi-omics of same tissue samples provides a powerful approach for us to look into the intrinsic responses of rice plants to drought stress.

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P 5.41 - A study on the effect of root characteristics in relation to the drought tolerance and grain yield in some RILs of durum wheat (Triticum turgidum L. var. durum) at rainfed conditions Soud A.R.1, Al-Ouk M.W.1, Alzoubi H.1, Abdul K.A.1, Al-Khiti2, Nachit M.M.3(m.nachit@cgiar.org) 1 GCSAR-Douma- P.O.Box 113, Damascus, Syria; 2 Damascus University, Faculty of Agriculture, Department of Agronomy, Damascus, Syria; 3 ICARDA- P.O.Box 5466, Aleppo, Syria. The present study was conducted to determine the effects of root characteristics and their correlation with drought tolerance and grain yield in 112 RILs mapping population of durum wheat Cham1 x Lahn. Direct measurements of roots' depth in seedlings were conducted near flowering by sampling 144 plots of 112 RILs mapping population of durum wheat Cham1 x Lahn in addition to parents and 6 checks repeated 5 times each. Results showed the importance of the number and length of roots and its distribution in soil layers for drought tolerance, where there was a very strong correlation of 0.809 between grain yield and number of roots distributed in the upper layer at a depth of 10 cm (with average of 765 roots) and a range between 678 and 919 roots for the 6 lines that gave the highest grain yield representing 5% of the total lines studied. Line number 2004 gave the highest yield with root number of 919 at a depth of 10 cm with grain yield of 1040 kg/ha. For the lowest 6 RILs, there was a very strong significant (positive) correlation at 0.1% level between the grain yield and root number at all tested depths. The parent Cham1 gave the highest grain yield of 584,3 kg/ha with root number of 929 at depth of 10 cm, while, the parent Lahn gave grain yield of 460,4 kg/ha with root number of 875 at a depth of 10 cm Increased roots number and length at depth of 60 cm had a positive effect on increasing grain yield. There was a positive correlation coefficient of 0.917 at 1% level between grain yield and each of root density at depth of 60 cm, length and dry weight of roots. 12 RILs mapping population of Cham1 x Lahn had significant difference in all traits studied in comparison with parents. There was a close correlation between the pattern of root characteristics and shoot growth and consequently grain yield.

P 5.42 - Trehalose accumulation in soil bacteria improves drought tolerance and biomass in crops plants Suárez R.1, Rodríguez-Salazar J.1, Caballero-Mellado J.2, Iturriaga G.1(iturri@uaem.mx) 1 Centro de Investigación en Biotecnología-UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos Mexico;

2 Centro de Ciencias Genómicas-UNAM, A.P. 565-A, Cuernavaca, Morelos, Mexico. Improving stress tolerance and yield in crops are major goals for agriculture. Here we show a new strategy to increase drought tolerance and yield in legumes and gramineae by overexpressing trehalose-6-phosphate synthase (TPS) in soil bateria interacting with plant roots. Phaseolus vulgaris (common beans) plants inoculated with Rhizobium etli overexpresing TPS gene had more nodules with increased nitrogenase activity and higher biomass compared to plants inoculated with wild type R. etli, whereas plants inoculated with a R. etli TPS- mutant had fewer number of nodules and less nitrogenase activity and biomass. Three-week-old plants subjected to drought stress fully recovered whereas plants inoculated with wild type or mutant strain wilted and died. The yield of bean plants inoculated with R. etli overexpressing trehalose-6-phosphate synthase gene, and grown upon constant irrigation increased more 57%. Macroarray analysis of 7200 ESTs from nodules of plants inoculated with the strain overexpressing TPS gene revealed up-regulation of genes involved in stress tolerance, carbon and nitrogen metabolism, suggesting a signaling mechanism for trehalose. We also assayed the effect of inoculating maize plants with genetically engineered Azospirillum brasilense for trehalose biosynthesis. Transformed bacteria with a plasmid harboring TPS gene were able to grow up to 0.5 M NaCl and to accumulate trehalose, whereas wild type

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A. brasilense did not tolerate osmotic stress neither accumulated significant levels of the disaccharide. Moreover, 85% of maize plants inoculated with transformed A. brasilense survived drought stress, in contrast with only 55% of plants inoculated with the wild type strain. A 73% increase in biomass of maize plants inoculated with transformed A. brasilense compared to inoculation with the wild type strain was found. In addition, there was a significant increase of leaf and root length in maize plants inoculated with transformed A. brasilense. Therefore, inoculation of maize plants with A. brasilense containing higher levels of trehalose confers drought tolerance and a significant increase in leaf and root biomass. This work demonstrates that increasing trehalose accumulation in soil bacteria interacting with plants could positively impact the biomass, grain yield and stress tolerance in relevant crops.

P 5.43 - A linkage map of a potential biofuel plant species Jatropha curcas Wang C.M. (chunming@tll.org.sg), Liu P., Sun F., Cao S.Y., Lo L.C., Feng F., Liu P., Yue G.H. Molecular Population Genetics Group, Temasek Life Sciences Laboratory, National University of Singapore, 117604 Singapore, Republic of Singapore. Jatropha curcas is becoming one of the world’s key energy crops, but need tremendous water to grow well. Its compact genome (210 Mb) is among the smallest genomes of plant. We established a first-generation genetic linkage map of Jatropha curcas with a mapping panel containing two backcross populations with 93 progeny. A total of 605 markers were developed and mapped into 11 independent linkage groups, which corresponding to the plant’s 11 homologous chromosome pairs. Among these markers, 216 were microsatellite, 290 SNP and 99 AFLP markers. The total lengths were 1880.3 cM with average marker spacing 3.11 cM. The average physical distance per centimorgan was observed to be 111.7 kb, showing high recombination rates for the Jatropha genome. The map will not only enable the mapping of quantitative trait loci underlying agronomic traits including drought resistance, but also provide new resources for understanding the evolution of Jatropha curcas genomes.

P 5.44 - Identification of QTL candidate genes and candidate pathways for drought tolerance in rice (Oryza sativa) by genome-wide temporal-spatial gene expression profiling Wang D.1, 4, Fu B.Y.1, 4, Sun H.X.2, 4, Zhao X.Q.1, Pan Y.J.1, Zhu L.H.1, Zhou Y.L.1, Rey J.3, Gao Y.M.1, Xu J.L.1, Wang X.J.2, Li Z.K.1, 3(lizhk@caas.net.cn) 1 Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement,

Chinese Academy of Agricultural Sciences, Beijing 100081, China; 2 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100081, China; 3 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines.

As the most important staple food for half the world population, rice is the most thirst crop that consumes disproportionally large amounts of fresh water. Rice is generally sensitive to drought as it is acclimated to either rainfed or fully irrigated paddy fields. The effect of drought on rice plants varies considerably with genotypes, developmental stages, degree and duration of drought stress. For example, rice is highly sensitive to drought at the panicle initiation and booting stages and rice yields are less affected by water deficit at the vegetative stage than that at the reproductive stage, even though drought stress at the early developmental stage does result in reduced height, fewer tillers and smaller leaf area. Drought stress causes a wide range of physiological and biochemical responses in plants, and drought tolerance (DT) in plants is a complex trait controlled by large numbers of genes. Identification of candidate genes and candidate pathways underlying DT has been one of the most challenging tasks in modern biology. By far, extensive genetic studies have identified large numbers of quantitative trait loci (QTLs) affecting DT and its component traits across the rice genome, revealing genomic regions harboring important genes underlying DT in rice. But classical mutation and QTL cloning experiments focusing on single genes or genomic regions are both time-consuming contain very limited information. We present a unique effort for efficient identification of QTL candidate genes and candidate pathways underlying DT in rice using a specifically constructed genetic stock and genome-wide spatial and temporal gene expression profiling. As a result,

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we find some candidate genes and candidate pathways related to DT in rice. Our results maybe provide some interesting lights into the molecular mechanisms underlying DT in rice.

P 5.45 - Interacting genes are less repeatable than additive genes in maize (Zea mays L.) Wang J.K.1 (wangjk@caas.net.cn), Li H.H.1, Messmer R.2, Ribaut J.M.3

1 Institute of Crop Science, CIMMYT China Office, and The National Key Facility for Crop Gene

Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China;

2 Add the affiliation of Rainer; 3 Generation Challenge Programme, c/o CIMMYT, Apdo. Postal 6-641, Mexico, D.F. 06600, Mexico. Epistasis makes a substantial contribution to the genetic control and evolution of quantitative traits. Our objective was to assess stability of epistatic effect cross a set of diverse environments and to determine if those genetic effects can be considered in marker-assisted breeding. Following a new approach based on inclusive composite interval mapping additive and di-genic epistatic effects were estimated in a recombinant maize line population evaluated under different years, locations and water regimes, for a total of 10 environments. For each of the trials large di-genic epistasis effects were identified for male and female flowering traits, respectively up to 48% and 51% in a single trial and to a less extend for plant height. The segregation of plant height was regulated mainly by a single QTL identified under 9 environments and expressing an average of 19% of the phenotypic variance (bin 1.06). Several loci with significant additive affects were identified across trials and in general a low correlation was observed between loci expressing additive and epistatic effects. Stable Epistatic effects were identified across experiments, as the result of same di-genic interaction between two loci across trials (plant height), or di-genic interaction between few regulatory genes, but with different loci depending to the environments (flowering traits). Major regulatory genes for flowering epitasis were identified on bins 2.08 and 10.05 for female flowering, bins 1.06, 8.04 and 10.04 for male flowering. Those genes might play a key role in plant adaptation, interacting with different genes involved in physiological pathways depending on environmental changes. The identification of large epistatic effects, some of them identified across trials, open new doors to achieve genetic gain and improve plant adaptability in maize.

P 5.46 - Genetic overlap between drought tolerances and sheath blight resistances in DTILs of rice Zheng T.Q., Li F., Xu J.L., Zhu L.H., Li Z.K. (zhkli@yahoo.com.cn) Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan-Cun St., Beijing 100081, China. Two introgression lines from two donors (Binam and Babaomi) in IR64 genetic background selected for drought tolerances (DTILs) with mild resistances against biotic stress (sheath blight, a fungal disease caused by Rhizoctonia solani) were intercrossed and backcrossed to develop three random populations (one pyramiding and two backcrossing) for the further investigation of the sheath blight resistances (SBR). From lines in F3 generation, extreme lines for sheath blight resistances were selected to evaluate the yield behavior under drought stress. Formerly identified loci for DT and SBR were traced in these lines by correlating with their DT and SBR performances. The genetic overlap between DT and SBR in these two DTILs were further investigated.

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P 6.01 - Genetic variation in Ethiopian durum wheat Alganesh Tesema G. 1(Adishihu@yahoo.com), Venderamin G.G., Porceddu E.2,3 1 Institute of Biodiversity Conservation and Research Addis Ababa, Ethiopia; 2 International Doctoral Programme in Agrobiodiversity, Scuola Superiore Sant Anna, Pisa, Italy; 3 Dipartimento di Agrobiologia e Agrochimica, Universita degli studi della Tuscia, Viterbo, Italy; 4 Istituto di Miglioramento Genetico Piante Forestali, C.N.R. Via Atto Vannucci 13, 50134 Firenze, Italy. Ethiopia has the second largest wheat growing area in Sub Saharan Africa, having 700,000 ha of arable land occupied by wheat. About two – thirds of this area is covered by durum wheat. Ethiopia is also one of the most important centres of durum wheat crop diversity. To evaluate this diversity eight different population, each composed by 25 genotypes were analysed by two microsatellite markers per chromosome. The Analyses revealed the presence of 224 alleles with sizes ranging from 125-282 base pairs. The total number of alleles per locus ranged from 4 to 17 with an average number of 8.The results indicated that the genome A was more variable than Genome B. The 6A long arm chromosome had the highest polymorphism whereas the 3B, 6B, 3A, long arm and 4B, 5B, 5A short arm had the lowest The within population variation was higher than among populations and among regions. The pattern of variation as measured by molecular markers is discussed in view of identifying evolutionary forces responsible for maintaining genetic variation and assists in genetic resources conservation.

P 6.02 - Genetic evaluation of indica/indica recombinant inbred lines of rice under drought stress in target environment Amudha K.1, Senthil A.1, Poornima R.1, Suji K.K.1, Prince K.S.J.1, Senthilvel S.2, Babu R.C.1

(chandrarc2000@yahoo.com) 1 Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology, Tamil

Nadu Agricultural University, Coimbatore – 641 003, India; 2 Agricultural Research Station, Paramakudi, India. Drought is a major limitation for rice production in rainfed ecosystems. Development of high yielding drought tolerant rice cultivars will considerably improve rainfed rice production. The genetic improvement of adaptation to drought is addressed through breeding approaches by selecting for yield and its stability over locations and years and is slow in attaining progress. Alternatively, yield improvement in rainfed conditions could be achieved by identifying secondary traits contributing to drought tolerance and selecting for those traits in target environment. A subset of 330 recombinant inbred lines from a cross between IR20 (an improved lowland variety) and Nootripathu (a drought tolerant land race) was evaluated under water stress and irrigated conditions in target environment during 2008-09 rainfed season. Drought occurred during reproductive stage of the crop and resulted in significant reduction in panicle length, spikelet fertility and grain yield under stress. Variability studies showed high GCV and moderate to high heritability (broad sense) for productive tillers, spikelet fertility, biomass and harvest index both under stress and irrigated conditions indicating high scope for the improvement of drought tolerance by the way of simple selection. Productive tillers, spikelet fertility and biomass both under stress and irrigated conditions, plant height under irrigated and panicle length under stress conditions showed significant positive correlations and high direct effect on yield. To harness high yield combined with drought tolerance under rainfed conditions, breeders should give selection pressure on productive tillers, spikelet fertility and biomass production under stress condition in rice. The efficiency of breeding programme can be improved by complementing selection for yield with selection for secondary traits particularly spikelet fertility that contribute to yield in the target environment.

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P 6.03 - Association between aflatoxin contamination and N2 fixation in peanut under drought conditions Arunyanark A., Jogloy S. (sanun@kku.ac.th), Vorasoot N., Akkasaeng C., Patanothai A.

Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Muang, Khon Kaen 40002, Thailand. Drought tolerance may serve as an indirect selection for resistance to aflatoxin contamination. Symbiotic nitrogen fixation under drought conditions may be one important mechanism for drought tolerance of peanut. Therefore, nitrogen fixation and its related traits may be used as indirect selection of aflatoxin resistance. The aim of this study was to investigate the relationship between N2 fixation traits and aflatoxin contamination under different drought stress conditions. Two field experiments (during 2003/2004 and 2004/2005 dry seasons) were conducted in a split plot design with three water regimes (field capacity (FC), 2/3 available water (AW) and 1/3 AW) as main plot, and 11 peanut genotypes as sub-plot treatments. Data were observed on kernel infection by Aspergillus flavus, aflatoxin contamination, total nitrogen content, N2 fixation and its related traits viz. nodule number, nodule dry weight and nitrogenese activity (acetylene reduction assay; ARA). All parameters in this study varied depending on water regimes and genotypes. Amount of water transpiration had a positive significant influence on total nitrogen content and N2 fixation (r = 0.94** and 0.95**). On the other hand, total nitrogen content and N2 fixation were negative significant influence on kernel infection and aflatoxin contamination (r = -0.28* to -0.45**) across water regimes. The relationship were also found between nodule number, nodule dry weight and ARA with kernel infection and aflatoxin contamination (r = -0.14 to -0.60**) across water regimes. There were negative relationships between kernel infection and aflatoxin contamination with nitrogen content and N2 fixation in the whole plant and shoot under drought conditions (r = -0.26 to -0.67**). However, such relationship were positive relationships with nitrogen content and N2 fixation in seed and partitioning to seed (r = 0.22 to 0.54**). Moreover, There were negative relationships between kernel infection and aflatoxin contamination with nodule dry weight and ARA (r = -0.43* to -0.86**) under drought conditions. The observations indicated that genotype selected for high nitrogen content or N2 fixation and its related traits may also exhibit better aflatoxin resistance. Because measurement for nodule dry weight was simple, it may be practical for application in breeding programs.

P 6.04 - High throughput phenotyping method for water use efficiency in rice under field conditions Audebert A.1(alain.audebert@cirad.fr), Chatel M.1,2, Grenier C.1,2, Ospina Y.2, Rodriguez F.2

1 Cirad UPR AIVA, F-34398 Montpellier, France ; 2 CIAT/Cirad A.A.6713, Cali, Colombia. A collaborative CIAT/Cirad project aims to create new improved upland rice germplasm for drought tolerance based on population improvement through recurrent selection (RS). In the framework of a multidisciplinary team (ecophysiology, molecular genetics and breeding), we seek to enhance this breeding strategy through the integration of marker-assisted breeding tools. This requires improving methods for high throughput phenotyping in the field. Four hundreds lines selected from diverse recurrent populations were screened under drought conditions in Villavicencio CIAT experimental station (Colombia) during the dry season 2008/2009. Drought stress was applied for two weeks at panicle initiation stage. Drought response under water deficit at flowering stage was evaluated based on soil moisture and canopy temperature at flowering with an infra-red thermographic camera and final grain yield. Leaf temperature at/around flowering stage exhibited strongly significant varietal differences that were negatively correlated with soil moisture content and yield. This phenotyping approach permitted identifying genotypes that display good maintenance of transpiration (and thus sustained growth) under drought stress, related mainly to limited water extraction and/or greater root depth; it also enabled identifying genotypes that have high transpiration

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rates (and thus higher potential growth rates) under irrigated control conditions. Selecting suitable combinations of both characteristics is expected to help identifying drought tolerant material with high yield potential. The methodology will be further improved by (1) including on each thermographic photo a wet/dry object to normalize canopy temperatures against weather fluctuations for situations where micro-meteorological backup is not available, and (2) sampling leaf material for complementary delta 13C measurements indicative of transpiration efficiency (TE). The integrated methodology is being implemented in RS breeding schemes and in parallel in a genetic association study on a japonica rice variety panel, in order to identify promising genomic regions and polymorphisms for marker development. This will eventually permit developing efficient marker-assisted recurrent selection (MARS) approaches.

P 6.05 - Participatory varietal selection helps in identification and release of high yielding rice variety suitable for drought prone rainfed ecosystem in Tamil Nadu, India Babu R.C.1(chandrarc2000@yahoo.com), Jeyaprakash P.1, Murugan E.1, Ananda kumar C.R.1, Gurumurthy S.1, Senthilvel S.1, Kumar S.S.1, Senthil A.1, Ganesh S.K.1, Robin S.1, Kumar A.2, Serraj R.2

1 Tamil Nadu Agricultural University, Coimbatore – 641003, India; 2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines. Scientists-led, formal plant breeding programs (FPB) have been highly effective in producing input-responsive, broadly adapted cultivars of annual grain crops. However, the products of FPBs have not been widely adopted by resource-poor farmers in marginal environments. Participatory approaches in which farmers also share responsibility in the development or evaluation of cultivars are more likely to produce varieties acceptable to farmers in marginal environments. Participatory varietal selection (PVS) is one such scheme wherein farmers evaluate finished varieties on-station or test them in their fields under their own management practices. PVS programs were shown to be successful in developing rice cultivars suitable for rainfed environments. PM 01 011 (PMK 4), is an high yielding rice suitable for drought prone rainfed environments that has been identified through PVS and released recently in Tamil Nadu state, India. The culture, PM 01 011 was selected from IET 16704 (Pantdhan 10 x IET 9911) in 2001 and further evaluated through PVS for potential yield, drought resistance and superior grain quality involving farmers in Ramnad and Sivagangai, two major rainfed districts of Tamil Nadu, India. It is semi dwarf (100-110 cm), erect, non-lodging and early maturing (100-105d). In ‘on station’ trials conducted for six years continuously, the culture gave a mean yield of 3181 kg/ha, 15.3% higher over check under rainfed conditions. In over 156 on farm and adaptive research trials, the culture gave an average yield of 3740 kg/ha, 14.7% increase over the check. The culture also gave higher yields under irrigated conditions and is fertilizer responsive. Besides yield, the culture was highly preferred by farmers for its long slender white grains with good cooking qualities, early maturity (by 7-10 d), medium plant height, non-lodging habit and ability to withstand water inundation for shorter periods. It fetches higher price in the market than the check, PMK 3 and land races. PVS is thus overcomes the inefficacy in formal breeding in developing varieties that do not meet farmers’ requirements, particularly in marginal environments. PVS thus enabled in identifying and release of this high yielding rice suitable for drought prone rainfed districts and we expect the PVS scheme will facilitate its rapid and wider adoption as well.

P 6.06 - Enhancing cotton production coping with drought: insights from marker assisted selection Boopathi N.M.1(nmboopathi@tnau.ac.in), Ravikesavan R.2, Gopikrishnan A.1, Thiyagu K.2, Kumar K.B.2, Saravanan N.2, Malthi N.2, Santosh M.2, Rajarathinam S.2 1 Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology; 2 Department of Cotton, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore 641003, India.

Genetic improvement of cotton (Gossypium spp.,) under water limited environments is considered as an important breeding goal since more than 70% of Indian cotton cultivation experiences water stress which rigorously affects

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fiber quantity and quality. Conventional breeding methods for drought resistance improvement have met with limited success due to several reasons including lack of complete knowledge on drought resistance. Genetic dissection of drought resistance and fiber quality traits under water stress using quantitative trait loci (QTL) mapping offers new avenue in increasing the efficiency of cotton breeding. The experiences gained by the lead author from the rice project has helped him to generate mapping populations such as F2, back cross and recombinant inbred lines after screening the cotton germplasm for drought resistance. The mapping populations being developed by this team are considered as valuable assets to genetically dissect out the complex quantitative traits such as drought resistance, viral resistance, lint yield, fibre quality parameters etc., since parental lines that are equally well adapted to target rainfed environments and possessing contrasting variation in the above said traits were employed. Further, use of effortless, cost effective and efficient PCR based marker systems such as simple sequence repeats (SSR) and Sequence Related Amplified Polymorphism (SRAP) is being used in construction of genetic map and it has been proposed to screen the mapping populations under water stress in multiple environments. This should help in identification of simple markers associated with consistent QTLs across the genetic backgrounds and environments. Upon identification of markers tightly linked to consistent QTLs associated with drought resistance and fiber quality traits under water stress, marker assisted selection will be efficiently executed for genetic improvement of cotton under water limited environments.

P 6.07 - Environment characterisation as an aid to improve wheat adaptation in water-limited environments Chenu K.1 (karine.chenu@dpi.qld.gov.au), Hammer G.L.2, Dreccer F.3, Chapman S.C.4

1 APSRU, Primary Industries and Fisheries, Toowoomba, Qld 4350, Australia; 2 APSRU, School of Land, Crop and Food Sciences, University of Queensland, Brisbane, Qld 4072,

Australia; 3 CSIRO Plant Industry, Cooper Laboratory, Gatton, Australia; 4 CSIRO Plant Industry, QBP, Brisbane, St Lucia, Qld 4072, Australia. Under water-limited conditions, substantial genotype-environment interactions impede crop improvement for yield. In breeding programs, accurate characterisation of the target population of environments (e.g. soil, climate, management) can help in the design of evaluation trials and in their analysis to select well-adapted germplasm. By capturing the interactions of plants with their environment, crop models have been demonstrated as efficient tools to characterise the nature of water-limited environments as experienced by crops. Further, crop simulation studies can help in understanding genotype-environment interactions and in assessing the potential value of key adaptive traits in each environment type. In this study, an environmental characterisation was undertaken for dryland wheat in North East Australia, where particularly large spatial and temporal variability occurs in the seasonal pattern of water availability. Simulations based on more than 100 years of historical climate data were conducted for representative locations, soils and management systems, for the commonly grown cultivar, Hartog. Based on analysis of patterns of simulated water stress through the crop cycle, four environment types were identified and their frequencies of occurrence determined. Cultivars differing in maturity were simulated and their performance in the different environment types interpreted. The simulations reproduced the expected genotype-environment interactions between maturity and stress patterns, thus indicating the potential for the technique to unravel more complex trait-environment interactions. Simulations assisted in the understanding of key adaptive traits associated with improved performance in each environment type, with flowering date and the amount of water use pre- and post-anthesis having a major role. The potential of environmental characterisation for plant breeding is discussed.

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P 6.08 - Association mapping of yield in a core collection of wheat grown in different water regimes Dodig D.1 (dejanza@yahoo.com), Zorić M.2, Kandić V.1, Kobiljski B.3 1 Maize Research Institute , ‘Zemun Polje’, Slobodana Bajica 1, 11185 Belgrade, Serbia; 2 Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia;

3 Research Institute of Field and Vegetable Crops, Maksima Gorkog 30, 21000 Novi Sad, Serbia. In association mapping, phenotypic diversity is surveyed among a population of individuals with varying degrees of relationship, followed by identification of marker polymorphisms that correlate with phenotypic variation. To avoid false-positive results due to unrecognized population structure in the analyzed group of individuals, the subpopulations need to be identified. A set of 96 common wheat (Triticum aestivum L.) genotypes of worldwide origin, including cultivars and breeding lines, were characterized with 36 genome-wide SSRs for genetic diversity and population structure. Genetic diversity among these genotypes was examined using a genetic distance-based and a model-based clustering methods. The model-based analysis identified an underlying population structure, consisting of four main dinstict subpopulations for the whole genotype set, corresponding well to four major distance-based groups. Among all of the genotypes, 58.3% were assigned into the corresponding subgroups, while others were assigned into a mixed subpopulation. Analysis of molecular variance (AMOVA) showed that 87.6% of the total variation could be explained by the variance within the subpopulation groups. The partial least squares (PLS) regression method was used to interpretate subpopulation × environment interaction (GEI). The effect of population structure on association mapping was tested on a three-year data of grain yield under three treatments: well-watered, rainfed and water-stress. Using subpopulation assignments as covariates, 47 significant (P < 0.05) marker-yield associations were detected in all nine year-treatment combinations. Respective SSR loci showed significant associations from one to seven environments. For yield under water-stress significant associations were detected at the SSR loci psp3153 (on chromosome 2A), psp3009 (2A), gwm484 (2D), psp3009 (6B), and psp3200 (6D). The study confirmed that association mapping using SSRs and genetically diverse germplasm provides an effective means of relating genotypes to complex quantitative phenotypes. Also, the results improved our characterization of the germplasm used and will assist the selection of new crosses for drought stress conditions.

P 6.09 - Response of rain-fed wheat genotypes to drought stress using drought tolerance indices Drikvand R.(drikvand_f@yahoo.com) Azad university Khoramabad branch. To identify drought tolerance genotypes according to drought tolerance indices, 10 rain-fed wheat genotypes were tested in a randomized completely block design with three replications under two irrigated and rainfed conditions at Lorestan Agricultural and Natural Resources Research Center (A Province from IRAN). Indices of drought tolerance were calculated based on the potential (Yp) and under stress (Ys) yield. The results of analysis of variance of indices exhibited highly significant differences among the GMP, MP and STI and non-significant differences between the SSI and TOL indices. This indicating the existence of genetic variation for the attributes studied and the possibility of selection for drought tolerance genotypes. Highest significant positive correlations were found among GMP, MP and STI indices and potential and stress yield. The highest geometric mean productivity (GMP), mean productivity (MP), and stress tolerance index (STI) were related to the TV2 genotypes. Principal component analysis reduced five indices down to two component with 99.49% proportional cumulative variance. Correlation analysis, among indices, mean potential and stress yield and demonstrated biplot using relationships among above indices indicated that the most suitable criteria for the identification of genotypes under irrigated and rain-fed condition were GMP, MP and STI indices. Evaluation of three dimentional plot exhibited that TV2 was the best drought tolerance genotype. Results of biplot analysis, similarity identified same genotypes as highest yielding once in both conditions. Based on cluster analysis TV2, Ghahar and Symareh genotypes with high yield were in a group and Sardari, Azar2 and Shahivandi genotypes with low yield were in a group. These genotypes showed the farthest genetic distance.

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P 6.10 - Future developments for non destructive 3D plant and root imaging Eberius M.1 (joerg@lemnatec.com), Jung A.2, Koch M.3, Specht K.4, Vandenhirtz D.1, Vandenhirtz J.1, Ricarda v.d. Heijden2 1 LemnaTec, 18 Schumanstr., Wuerselen 52146, Germany; 2 Beta-Klinik, Joseph-Schumpeter-Allee 15, Bonn 53227, Germany; 3 IHF, TU Braunschweig, Schleinitzstr. 22, Braunschweig 38106, Germany; 4 University of Bergen, Jonas Lies vei 91, Bergen 5009, Norway. High-throughput screening and high-throughput phenotyping have become key technologies for research in and development of active ingredients for pharmacology, new plant protection compounds and breeding for new traits in agricultural products. These technologies are fundamentally important for many fields of applied and basic research, enabling the examination and understanding of different plant gene functions and the overall effects of chemicals on various organisms. Most of these screening methods are measuring visible parameters of the plants such as color, shape, size, area, architecture, growth rate, performance or movement. Therefore digital imaging of plants has become a very important tool in plant research, since modern image processing software algorithms are much better and more reproducible in quantifying these visual parameters than the human eye. Moreover the spectrum of modern CCD cameras can be extended to lower or higher wavelengths far beyond the visual range of the human eye such as Near Infrared (NIR) for measuring the water distribution and dynamics in plants during drought stress experiments. However all this reflective measurements are just able to target the visible part of the plant, the shoot, while the root keeps to be hidden in the soil or substrate. The goal of this joint study is, to explore weather Nuclear Magnetic Resonance Imaging (NMRI) or (Sub) Terahertz Imaging (THz) might be used for obtaining non invasive and valuable information about plant roots in soil or substrate.

P 6.11 - Screening for drought adaptation in peanut (Arachis hypogaea L.) using transpiration efficiency and specific leaf area Faye I.1,2 (issafaye2001@yahoo.fr), Vadez V.3, Ndoye O.1 1 Institut Sénégalais de Recherches Agricoles, Centre National de Recherches Agronomiques (ISRA/

CNRA) BP 53 Bambey, Sénégal; 2 Université Cheikh Anta Diop (UCAD)-Département de Biologie Végétale, Dakar, Sénégal; 3 International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Patancheru 502324, Andhra

Pradesh, India. The level of transpiration efficiency (TE) is usually associated with yield variation in peanut (Arachis hypogaea L.) grown under intermittent moisture stress. Here, the TE of a set of 100 diverse peanut accessions was compared to that of two Senegalese peanut varieties, one of which is drought tolerant, and the other relatively drought sensitive. We also evaluated specific leaf area (SLA) as a surrogate trait for TE, which itself was gravimetrically measured under a progressively drying soil in a pot experiment during the off-season. For these experiments, the plants were exposed to a day/night mean temperature of 36/21 and a relative humidi℃ ty of 14.5% to 100%. Extensive genotypic variation was observed for both TE and SLA. The level of TE ranged from 1.09 to 3.38 g kg-1 and of SLA from 125 to 289 cm2 g-1. An analysis of variance demonstrated significant inter-accession differences in TE. The TE of accession ICG 928 was superior to that of the drought tolerant check variety 55-437, and twelve others out-performed the sensitive check variety, Fleur 11. SLA measured at the completion of the moisture stress period was negatively correlated with TE, but although this relationship was statistically significant, it was too weak (5%) to encourage the use of SLA as a surrogate selection criterion for TE.

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P 6.12 - Heritability estimates of the physiological traits for terminal drought tolerance and genotypic and phenotypic correlation with agronomic traits of peanut (Arachis hypogaea L.) Girdthai T.1, Jogloy S.1 (sanun@kku.ac.th), Vorasoot N.1, Akkasaeng C.1, Patanothai A.1, Holbrook C.C.2 1 Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen Univer-

sity, Muang, Khon Kaen 40002, Thailand; 2 USDA-ARS, Crop Genetics and Breeding Research Unit, Coastal Plain Experimental Station, Tifton,

GA 31793, USA. Improvement of terminal drought resistant in peanut can increase their productivity under drought-prone environment and reduce aflatoxin contamination. To improve selection efficiency for superior drought tolerant genotypes, a study of inheritance of trait is worthy and useful information for plant breeding approach. The objectives of this study were to estimate the heritability of terminal drought resistance traits, genotypic and phenotypic correlations between drought resistance traits and agronomic traits in peanut under well-watered and terminal drought conditions, and relationship among drought resistance traits. The 140 peanut lines in the F4:6 and F4:7 generations were generated from different four crosses, and tested under field capacity (FC) and 1/3 available soil water (1/3 AW) at 80 days after planting until final harvest. Field experiments were conducted under the dry seasons 2006/07 and 2007/08. Data were recorded for agronomic traits [Biomass (BIO), pod yield (PY), harvest index (HI), number of mature pods per plant (PPP), seed per pod, and seed size] and physiological traits [Specific leaf area (SLA) and SPAD chlorophyll meter reading (SCMR)]. Year x genotypes interaction effects for SCMR and SLA were lower than PY and BIO. The h2 for physiological traits were higher than agronomic traits, and vary among crosses. The h2 for HI, SLA and SCMR were range from 0.58 to 0.91. Positive correlations between traits under different water regimes were significant for PY, BIO, HI, SCMR and SLA (r = 0.34-0.44), indicating that these traits could be selected under both well-watered and terminal drought conditions. Significant correlation between drought resistance and agronomic traits were observed. Genotypic (rG) and phenotypic (rP) correlations between traits were parallel. Strong and positive correlation between HI and PY, PPP, and seed per pod were found (rG = 0.48 to 0.78). Positive correlation between SCMR and PY, BIO, and seed size were also significant (rG = 0.21 to 0.35). SLA were negative correlated with agronomic traits (rG = -0.07 to -0.34). Correlation among drought resistance traits were found under both water regimes. This result implies that HI, SLA, and SCMR are potentially useful as indirect selection traits for terminal drought resistance because of low genotypes x environment interactions, high h2, and correlated with PY, BIO, and other agronomic traits. Plant breeding approach using these traits might be effective and valuable for improving drought tolerance in peanut.

P 6.13 - Physiological traits for drought tolerance as indirect selection tools for lower aflatoxin contamination in peanut (Arachis hypogaea L.) under terminal drought Girdthai T.1, Jogloy S.1(sanun@kku.ac.th), Vorasoot N.1, Akkasaeng C.1, Patanothai A.1, Holbrook C.C.2

1 Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Muang, Khon Kaen 40002, Thailand;

2 USDA-ARS, Crop Genetics and Breeding Research Unit, Coastal Plain Experimental Station, Tifton, GA 31793, USA.

Preharvest aflatoxin contamination in peanut when subjected to terminal drought is a major problem worldwide. Selection for drought tolerance genotypes can be an efficient strategy for reducing aflatoxin contamination. Physiological traits for drought tolerance could be used as indirect selection tools to reduce aflatoxin contamination in peanut. The objectives of this study were to determine the effects of terminal drought on Aspergillus flavus colonization and aflatoxin contamination and to investigate the associations between surrogate traits for drought tolerance and aflatoxin contamination. Field experiment under rainout shelters were conducted in the dry seasons 2004/05 and repeated in the dry seasons 2005/06. A split-plot design with four replications was used. Two water regimes (field capacity (FC) and 1/3 available soil water (1/3 AW) at 80 days after planting to final harvest) were assigned in main plots, and eleven peanut genotypes were assigned in subplots. Data were

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recorded for physiological traits, total biomass, pod yield, drought tolerance index (DTI), A. flavus colonization, and aflatoxin contamination. This study found that drought resistant genotypes were resistant to aflatoxin contamination. The genotypes ICGV 98305, ICGV 98348, ICGV 98353, and Tifton- 8 which are elite drought resistant lines were observed to have low aflatoxin contamination. Multiple regressions showed that the contribution of surrogate traits for drought tolerance to A. flavus colonization and aflatoxin contamination were not consistent across years. However, physiological traits for drought tolerance are consistently related to aflatoxin contamination in peanut under terminal drought, and close associations were observed for seed colonization and aflatoxin contamination between the two years under both water regimes. Negative and significant correlations between DTI of biomass and A. flavus colonization and aflatoxin contamination (r = -0.52 to -0.67, P≤0.05) indicated that increasing drought tolerance resulted in reduced aflatoxin contamination. Negative and significant correlations between aflatoxin contamination and chlorophyll density, and relative water content (r = -0.58, P≤ 0.05 to r = -0.75, P≤0.01) were also found. Positive correlations between aflatoxin contamination and specific leaf area, drought stress rating, and canopy temperature were significant (r = 0.58, P≤0.05 to r = 0.77, P≤0.01). This result reveals that drought tolerant traits have the potential to serve as indirect selection tools for lower preharvest aflatoxin contamination. These traits can also be used as efficient tools for selection of peanut genotypes with terminal drought tolerance and low levels of aflatoxin contamination.

P 6.14 - Study on the hybrid F3 progeny of cultivar rice（Oryza sativa）and wild rice（Oryza rufipogon）in water stress condition Guan D.M.1 (gdming@cumtb.edu.cn), Lafitte R.2, Zhao M.3, Kuang T.Y.4, Zheng S.Q.1, Liu F.Z.1 , Guo Z.F.1

1 College of Chemistry and Environmental Engineering, China University of Mining and Thechnology

(CUMTB), Beijing 100083, China; 2 Crop Soil and Water Sciences (CSWS) Division, International Rice Research Institute (IRRI), DAPO

7777, Metro Manila, Philippines; 3 Chinese Academy of Agricultural Sciences (CAAS), Beijiing 100081, China; 4 Institute of Plant Science，Chinese Academy of Science, Beijing 100093, China. The hybrid F3 progeny of cultivar rice（Oryza sativa）and wild rice（Oryza rufipogon）was studied the photosynthetic rate and some other traits relative to drought resistance. The cross of Azucena and Rampur6 produced the F1 plant（25007-10），and got the F3 progeny through self-cross. The physiological characteristics of the plants with different photosynthetic rate were studied in water stress condition. The results showed: (1) Predawn leaf water potential decreased greater, however midday water potential decreased less in plants with high photosynthetic rate than in plants with low photosynthetic rate. It showed that midday water potential was correlative to photosynthetic rate in water stress condition. (2) The electrolyte leakage decreased in all plants in mild water stress condition (0-40 days) and the stability of membrane improved; with the longer of water stress (40-80 days), the electrolyte leakage increased. It may be due to the increment of organic solute accumulation by osmotic regulation and destruction of membrane stability. (3) It can be seen from the plants with different photosynthetic rate that the photosynthetic rate declined greater in the plants with high photosynthetic rate than in the plants with low photosynthetic rate in water stress condition. There was stronger drought resistance in SHP1-2 plants than in SHP1-1 plants in water stress condition. (4) The stomatal resistance rose in all plants with different photosynthetic rate in water stress condition. The increment of stomatal resistance was higher and earlier in plant with low photosynthetic rate than the plants with high photosynthetic rate.

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P 6.15 - Morpho-physiological traits and yield performance of drought-resistant rice lines developed by designed QTL pyramiding Guan Y.S.1,2, Li Z.K.1,2 (zhkli@yahoo.com.cn), Serraj R.1 (R.Serraj@cgiar.org)

1 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines; 2 Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement,

Chinese Academy of Agricultural sciences (CAAS), Beijing 100081, China. To verify the effectiveness of a new breeding strategy –improvement of drought tolerance (DT) in rice by designed QTL pyramiding, 42 2nd round pyramiding lines (PDLs) in the IR64 background were developed from F2 populations derived from crosses between 1st round PDLs each with multiple DT QTLs from 2 different donors. These 2nd round PDLs were evaluated in the replicated field experiments under multiple hydrological regimes at IRRI in two consecutive dry seasons (2007 and 2008). Compared to the recurrent parent (IR64), the PDLs showed significantly improved yield under flooded conditions, vegetative stress, and mild and severe reproductive stress. Path analysis revealed that yield increase under drought in the PDLs was associated with improvements in multiple morpho-physiological and yield component traits and a general improvement of plant water status under drought. A selected set of promising PDLs was further analyzed for the dynamic responses of plant growth and water use to progressive water deficit in lysimeters under controlled phytotron conditions. The PDLs that performed best under drought were those that had the lowest threshold of transpiration response to soil moisture decrease, i.e. lines that kept stomata open longer during the soil drying, and hence extracted more soil water, which resulted in higher shoot and root biomass, and an overall improvement of transpiration efficiency. These results demonstrated the possibility of genetically combining high yield potential, DT and water use efficiency by combining multiple drought QTLs through appropriate design of crosses based on parental QTL information and high throughput and precise drought phenotyping.

P 6.16 - QTL pyramiding for multiple traits and development of drought tolerant aerobic rice (Oryza sativa L.) in India Hittalmani S.1 (shailajah_maslab@rediffmail.com), Biradar H.1, Mahesh H.B.1, Rudresh N.S.1, Venkatesh G.R.1, Sheshashayee M.2, Nagabhushana K.1, Keshava M.B.C.1, Pranesh M.K.1

1 Marker Assisted Selection Laboratory, Department of Genetics and Plant Breeding, University of

Agricultural Sciences, GKVK, Bangalore-560 065, India; 2 Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore-560 065,

India. With depleting water situation in India, rice varieties for water scarce situation are need based to keep up the rice production. WUE, roots and grain yield under drought decide the grain yield. QTLs for these traits have been fine mapped pyramided and markers identified. They were evaluated for yield under stress and aerobic (limited irrigation) situation. IR64 NILs back crossed and selected for two generations, pyramided using markers for 4 root QTLs on four rice chromosomes and with WUE QTLs plants and NILs with high grain yield. SSR markers were used to test the presence QTL plants (Chr. 1, 2, 3, 5, 7, 8, 9, 10). The delta values for water use efficiency low in two QTL combinations for two traits with significantly high grain yield and with long roots of QTLs on Chr. 1, 9 and 2 for roots. The most water efficient plants are not necessarily the highest grain yielders but moderate compromise on grain yield needs to be made to select genotypes with high water use efficiency and high grain yield. Pyramids expressed both additive and epistatic effects for all the three traits combinations. Multi-location trials of pyramided genotypes in several locations for five years including farmer participatory approach indicated superior performance of QTL pyramids across wider environment with superior grain yield over check. Selected pyramids were tested in dry land soils with 350 to 400 mm of water. Maximum of 7 tons per ha yield was observed and 3 tons of grain yield in rainfed drought situation. The aerobic rice varieties are recommended for rainfed and limited water available areas.

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P 6.17 - New potato varieties with large root mass and high tuber yield Iwama K. (iwama@res.agr.hokudai.ac.jp) Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan. Potato has a shallower and less dense root distribution in the field compared with other field crops, and is considered to be highly sensitive to drought stress. To avoid drought stress, we bred new potato varieties with large root mass using root dry weight (DW) in the plow layer and tuber starch yield (SY) as selection criteria from a cross between Irish Cobbler (early maturity, good eating quality, the top share in Japan) and Konafubuki (late maturity, high SY, the second share in Japan). We sowed 2000 true potato seeds of the cross in a nursery and the seedlings were transplanted into pots at the fourth leaf stage. After about 2 months, 312 seedlings were transplanted into the field. After the leaf yellowing stage (maturity stage), all genotypes were harvested and the tuber fresh weight was recorded. For the next clonal generation, 58 genotypes were selected. The selected genotypes had larger tuber fresh weight, i.e. at least six tuber pieces of each 20 to 100 g, for making six hills in the first clonal generation. Root DW to the depth of 30cm from soil surface was measured at the maximum shoot growth stage in the first, second and fourth clonal generations. Root DW of 46 genotypes in the first clonal generation varied from 0.18 to 3.93 g hill-1 and correlated significantly with SY (r =0.752**). Based on root DW and SY, 36 genotypes and 15 genotypes were selected for the second clonal and the fourth clonal generations, respectively. Root DW correlated significantly between the first and second generations (r =0.691**) and between the second and fourth generations (r=0.760**). Broad sense heritability for root DW was similar to or slightly lower than for stem DW, tuber starch concentration and plant maturity class, but higher than for leaf DW, tuber fresh yield and SY. Based on the mean values over three generations for root DW and SY, four genotypes were finally selected and registered as potato variety, ‘Konyu’, with the Ministry of Agriculture, Forestry and Fishery of Japan in 2007.

P 6.18 - Genetic variability of mean root diameter in the mini-core germplasm collection of chickpea（Ciecer arietinum L.） Iwasa T.1, Terauchi T.1,2, Kashiwagi J.1,3, Iwama K.1,4 (iwama@res.agr.hokudai.ac.jp)

1 Crop Science Laboratory; Department of Botany and Agronomy; Graduate school of Agriculture,

Hokkaido university, Sapporo, 060-8589, Japan; 2 Presently National Agricultural Research Center for Kyushu Okinawa Region, Japan; 3 Pastly International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), India. Under terminal drought condition, large and deep root system is one of the most important traits for absorbing soil water in chickpea. In our previous work, mean root diameter of surface soil layer (0-30 cm in depth) related to water absorption ability from deep soil layer (30-100 cm in depth) in 4 chickpea genotypes. In the present study, we investigated genetic variability of morphological traits for shoot and root including mean root diameter among chickpea mini-core germplasm collection of ICRISAT (207 genotypes) and previous 4 genotypes. The plant was grown in a pot (6cm diameter, 20cm height) and sampled at 35 days after sowing. There were significant differences between genotypes for all traits measured. Root diameter and stem diameter had higher broad sense heritability than other traits. Root diameter was significantly correlated to the stem diameter, suggesting that stem diameter can be used for rough selection of root diameter during early growth stage. Two outstanding genotypes with large root traits, ICC 2277 and ICC 13187 were identified among the mini-core germplasm collection. Their root diameter was significantly thicker than that of ICC4958 which was reported to have high drought resistance at ICRISAT. We also identified 5 genotypes which had large shoot biomass but different root length and diameter, i.e. ICC 2277 and ICC13187 (large root length and thick roots), ICC 7411 (large root length and thin roots), ICC 11764 (small root length and thick roots), ICC 3761 (small root length and thin roots). These 5 genotypes may be suitable to test the relationship of root traits with drought resistance in fields.

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P 6.19 - Interactive effects of water stress and salinity on carbon isotope discrimination by wheat cultivars Kenzhebayeva S.S.1(kenzhebaevas@mail.ru), Adu-Gyamfi J.J.2, Alibaeva R.A. 1 Kazakh State University named al-Farabi, 050038, al-Farabi, 71, Almaty, Kazakhstan; 2 Soil Science Unit, International Atomic Energy Agency (IAEA), Wagramer Strasse 5, A-400, Vienna, Austria. Crop yield in salt-affected areas in the semi-arid environments is frequently limited by salinity and low moisture availability. Identifying a desirable trait in these environments would be useful to selecting and evaluating crop plants tolerant to low moisture availability and high salt concentrations. The CID has been proposed as a possible selection criterion for greater water use efficiency in breeding programs for water limited and salt stress environments because it provides an integrative assessment of genotypic variation in leaf transpiration efficiency. We assessed the potential carbon isotope discrimination technique to quantify the interactive effects of water and salt stress and to evaluate and select wheat varieties in combined soil salinity and water deficit environments. Four wheat varieties (Saratovskya-29, Severyanka, Stepnaya-15 and Otan-1) were grown in a glasshouse experiment. Six treatments including (i) control (water applied at field capacity throughout the experiment without salt treatment, (ii) drought 1 (D1, water applied at 30% FC 8 d after thinning) (iii) drought 2 (D2 water applied at 30% FC at 50% booting) (iv) salt (S 50 mM or 10 dSm-1 applied 8 and 10 days after thinning in 2 splits) (v) drought 1 x salt interaction (D1 x S) and (vi) drought 2 x salt (D2 x S water stress and salt applied at 50% booting). The D1 and the D1 x salt treatments resulted in a more drastic reduction in DM of spikes than all the other treatments suggesting that the pre-anthesis water stress contributed more to a reduction in DM than the salt stress treatment. Delta values were higher in shoot and roots than in the spikes. Significant variations in mean ∆ values due to the treatments were observed for wheat varieties ranging from 21.3 ‰ for the control to 17.6‰ for D1 x S1 treatment. Results showed that water stress at the early crop growth had a more severe consequence on the DM and ∆ than the effect of salt in wheat. The combined effect of water and salt stress resulted in a less discrimination or low ∆ values in comparison with the control (well-watered and no salt treatment) and the individual water and salt stress treatments. High DM was associated with high ∆ suggesting a positive correlation between shoot DM and ∆. Cultivar differences in ∆ observed in the crops were not significant. Our data indicates that selecting crop plants for their greater agronomic efficiency in a combined salt stress and water deficit environments is complex and require further investigations in the field with more cultivars. Among the 4 varieties tested the high difference in ∆ value between control and drought 1 x salt interaction (D1 x S) and drought 2 x salt interaction (D2 x S) treatments recorded in Saratovaskaya-29, Severyanka and Otan-1 and Severyanka and Otan-1, respectively.

P 6.20 - Evaluation of lentil germplasm for traits imparting drought tolerance Kumar J., Solanki R.K., Singh S.K., Basu P.S., Kumar S. Indian Institute of Pulse Research, Kanpur-208 024, India. Lentil is one of most important pulse crops in India. It is mostly cultivated as rainfed crop under receding soil moisture conditions in winter season. As a result, the crop invariably encounters terminal moisture stress, thus, leading to forced maturity and lower yield. Among several traits imparting drought tolerance in lentil, long roots are known to enhance capacity of the plant to extract water from the lower soil strata and thus help to avoid the drought like situation. In view of this, we assessed genetic variability for root length of 43 lentil genotypes comprising released varieties, promising breeding lines and germplasm accessions. These genotypes were grown in PVC tubes in two replications during rabi, 2008-09. In each tube, four plants were maintained with 20% moisture level. The root length of each genotype was measured after 65 days. The root length ranged from 28.20 to 86.27 cm. The minimum root length was measured in L 4147 (28.20 cm) followed by ILL 7716 (30.54 cm). The maximum root length was observed in genotype P-98/193 (86.27 cm) followed by EC 542165 (85.10 cm). These genotypes were also grown under the rainfed conditions during rabi, 2008-09 in order to evaluate their performance for a number agronomicllly important traits including biomass, plant height, harvest index and SPAD value. Though genotypes with shorter root length showed poor biomass and harvest index (0.12 to 0.23%),

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genotype P-98/193 having the longest root length (86.27 cm) in the present study also showed poor biomass and harvest index (0.20%). However, genotype ILL-8114 had long root length together with average biomass and harvest index (0.33%). In general, genotypes varying from 54 to 62 cm for root length had average biomass and harvest index. Based on morphological data, euclidean distance was calculated to draw a UPGMA based dendrogram that revealed the distribution of above genotypes into different clusters. These preliminary results demonstrated existence of genetic variability for root length as well as other traits, which can be used as parents for development of mapping population to map QTL’s responsible for drought tolerance with an aim to develop drought tolerant high yielding varieties in lentil.

P 6.21 - Transgressive segregants for higher productivity and drought tolerance under water limited environments in barley (Hordeum vulgare L.) Lal J.P.(jplalbhu@yahoo.com), Singh H., Nandan R., Kumar H. Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India. The presence of promising recombinants yielding higher than the check (in present case K 603) is very important as it leads to isolation of pure lines in self pollinated crop like barley. The crosses between 5 rainfed varieties of barley, namely, K 603 x K 560, K 603 x RD 2508, Lakhan x K 560, K 560 x RD 2508 yielded 59 promising transgressive segregants under rainfed condition, while K 603 x K 560, K 603 x Geetanjali and Lakhan x Geetanjali yielded 64 transgressive segregants in irrigated condition. Of these, cross K 603 x K 560 was most remarkable as it gave higher number of transgressive segregants in both rainfed and irrigated conditions. Most of the promising segregants, irrespective of the parents involved, showed an enhanced level of proline content as expected particularly under rainfed as compared to irrigated condition. Further cross involving parents K603 and K560, with an average and good levels of gca ranking, respectively, for most of the traits yielded recombinants with promise in both the conditions. Therefore, the parents K 603 and K 560 coupled with Geetanjali should be given due consideration, while evolving promising recombinants. A total of twenty nine segregants showing significantly higher values of proline content and grain yield were grown during 2007-08 under both the environments, rainfed and irrigated to calculate the drought susceptibility index (S). Yield under rainfed (Yd) and yield under irrigated i.e. yield potential (Yp) were utilized to calculate S value. In the present study, selection was made on Yd value in the first instance, which was followed and supported by the data of drought susceptibility index and geometric mean (GM) to identity drought tolerant segregants. The segregants (Culture No. 8, 10 & 13) derived from cross K 603 x K 560 and culture No. 5 from K 560 x RD 2508 gave highest mean yield under rainfed. Maximum geometric mean was also associated with these segregants along with lower drought susceptibility index (S). The segregants, which showed least S value (< 1) were identified as drought tolerant and therefore, it might be concluded on the basis of Yd, Yp, GM and S values that the above cultures were drought tolerant. Also, it has been observed that the transgressive segregants selected from limited water environment (rainfed) performed better than the segregants selected from irrigated environment for higher grain yield and drought tolerance.

P 6.22 - Advances of drought-resistant water-saving breeding of wheat Liu X.M.1, 2 (yameixisi@163.com), Wang H.J.1

1 Hebei Academy of Agricultural Sciences, Shijiazhuang, Hebei 050051, China; 2 Institute of economics study, Hebei University of Economics & Business, Shijiazhuang, Hebei 050061,

China In this paper, the application of drought resistant breeding technique and biologic technique on drought-resistant breeding in wheat and its progress were discussed. and find that improving water use efficiency of wheat by breeding measures has been becoming an important research field in water-saving farming. And the problem of drought-resistant breeding and its development direction were analyzed.

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P 6.23 - Genetic diversity and agronomic performance of southern african maize varieties under abiotic stresses Magorokosho C.1 (c.magorokosho@cgiar.org), Bänziger M.2, Betrán J.3

1 Global Maize Program, International Maize and Wheat Improvement Center (CIMMYT), 12.5 Km peg

Mazowe Road, P.O. Box MP163, Mount Pleasant, Harare, Zimbabwe; 2 CIMMYT, P O Box 1041, Village Market-00621, Nairobi, Kenya; 3 Syngenta Seeds S.A.S.12, chemin de l'Hobit B.P. 2731790 Saint Sauveur, France. Large scale and planned introduction of maize (Zea mays L.) in southern Africa was accomplished during the last 100 years. Since then, smallholder farmers and breeders have been selecting varieties best adapted to their specific growing conditions and market needs. A study was conducted in 2004 and 2005 to assess the variability and performance of a core set of maize varieties collected in Zimbabwe, Zambia and Malawi. A total of 108 varieties comprising ancestral open pollinated varieties (OPV) introductions originating from the USA, early generation OPVs developed in southern Africa around the 1900s, traditional landraces and improved varieties were evaluated under low soil nitrogen, low soil pH, drought stress, random stress, and under optimum moisture and fertilizer levels. Results obtained showed the existence of considerable variation in agronomic traits under the different environments. Differences among the accessions, type of accessions (landraces, ancestors, early OPVs and improved) were significant for most of the traits studied. Genotype x Environment (GxE) interactions were also significant. Agronomic performance of maize varieties under different environments was used to create dendrograms, where materials were clustered into groups based on respective performance under specific environments. Estimates of broad sense heritabilities varied depending on traits and testing environments. However, these estimates were generally larger for each trait in the environment where the variance of that trait was highest. Genetic and phenotypic correlation coefficients also varied depending on traits and testing environments. Biplots constructed revealed which traits were closely related for each environment. Generally improved varieties outperformed landraces under all environments, but there were notable exceptions with many landraces yielding as much as improved varieties. Landraces were more stable than improved varieties across test environments, but improved varieties were more responsive to favorable growing conditions. The most promising landraces for pre-breeding and further investigation were identified.

P 6.24 - Characterisation of drought adaptive traits for the improvement of bread wheat in mediterranean environments Makdis F.1,2, Abdalla O.2, Hakim M.S.1, Ogbonnaya F.C.2 (F.Ogbonnaya@cgiar.org)

1 Aleppo University, Faculty of Agriculture, Field Crops Department, Aleppo, Syria; 2 International Centre for Agricultural Research in the Dry Areas, P O Box 5466, Aleppo, Syria. Drought is the most important abiotic stresses that affect bread wheat productivity in Mediterranean environments including Syria often exacerbated by the incidence of extreme temperatures during grain filling periods. In Syria, where most of bread wheat production is mostly rainfed, the long-term average rainfall is about 350 mm since record keeping began. However, in the past two decades, annual precipitation has been less than 300 mm for eleven of the twenty-year period. Consequently average yield varied between 0.3-1.8 ton/ha in the semi-arid regions within the last ten years. It is expected that this trend in drought would increase because of climate change. It has therefore become imperative to investigate adaptation options for improving yield and yield stability under these conditions. We present results from the preliminary trials of a recombinant inbred population between Cham-6 x Cham-8 that have been grown under diverse drought prone environments of Syria and Lebanon. Cham-6 is a dryland cultivar widely adapted to dry land condition while, Cham-8 is a standard spring type cultivar with high yield potential that is widely grown in the region. Both cultivars have similar phenology and maturity. This is aimed at determining which traits and trait combinations are most relevant to different drought scenario experienced in Syria and Lebanon. This will hasten the development of more resilient wheat cultivars to mitigate the impact of drought and improve income security for farm families.

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P 6.25 - Diallel analysis of grain yield and agronomic characters in tropical maize inbred lines under stress and nonstress environments Makumbi D. (d.makumbi@cgiar.org), Diallo A.O. International Maize and Wheat Improvement Center (CIMMYT), P.O. Box 1041-00621, Nairobi, Kenya. Drought is one of the major abiotic constraints to maize production in the mid-altitude ecology of sub-Saharan African. Efforts continue to identify drought tolerant maize germplasm from different sources. The objectives of this study were to evaluate single cross hybrid performance and assess the combining ability for grain yield and agronomic traits in a set of adapted tropical maize inbred lines under varying conditions. Nine inbred lines of diverse origins were crossed using a diallel mating design. The resulting F1 hybrids were evaluated under managed drought stress at two locations in Kenya and Zimbabwe, and well-watered conditions at three locations in Kenya and one location each in Ethiopia and Uganda. Drought stress was achieved by withdrawing irrigation water 2 weeks before male flowering. Measurements were taken on grain yield (GY), days to anthesis (AD), anthesis-silking interval (ASI), ears per plant (EPP), and leaf senescence. Variation among genotypes was highly significant (P≤0.01) for all traits except leaf senescence. General combining ability (GCA) effects were highly significant (P≤0.01) for GY, AD, ASI, and EPP under both managed drought stress and well-watered conditions. Significant (P≤0.01) variation for specific combining ability (SCA) was identified for GY, AD and EPP under both managed drought stress and well-watered conditions. The GCA effects were more important than SCA effects for all traits except leaf senescence, suggesting that these traits were controlled mainly by additive gene action in this set of lines. Inbred line CKL05005 had the highest significant GCA effect for GY across managed drought stress (1.43 Mg ha-1) and across well-watered conditions (1.62 Mg ha-1). Inbred line CKL05003 had the second highest GCA effect for GY under well-watered conditions (1.31 Mg ha-1). Inbred line CKL05005 also had the best GCA effect for EPP (0.28**), ASI (-4.20**), and AD (-5.24**) under managed drought stress. This inbred line was parent to the best hybrid (3.9 Mg ha-1) and also parent to 7 of the best 10 hybrids under drought stress. Under well-watered conditions the best hybrid (10.8 Mg ha-1) was a cross between the two inbred lines with the best GCA across well-watered conditions. Combining ability data suggests that inbred line CKL05005 is potentially a good source of alleles for drought tolerance and grain yield and could be beneficial for maize breeding programs in the mid-altitudes of East Africa.

P 6.26 - Intraspecific and interspecific estimation of drought resistance of different cotton varieties of G.hirsutum L. and G. barbadense L. species Mamedova A.D. (afet.m@mail.ru) Genetic Resources Institute of the Azerbaijan National Academy of Sciences, Azerbaijan. In individuals adaptation, i.e. process of adjustment of plants to a certain environmental conditions, is provided due to the physiological mechanisms (physiological adaptation), while in population of organisms due to the genetic variability mechanisms, inheritance and selection (genetic adaptation). Study of the changes in physiological parameters under the unfavorable factors reflects the individuality of special reactions of different varieties to stress. It is known that during the evaluation of resistance of plants to the stress factors it is necessary to be guided not on absolute resistance (changing with in different cycles of the evaluation), but their relative resistance (distinctions of the resistance level of varieties in comparison with each other; their relation to certain groups of resistance). Taking into account the above mentioned, we carried out a comparative evaluation the drought resistance of 100 varieties of G. hirsutum L. and 74 varieties of G. barbadense L. according to the stress depression parameters of seed germination and biosynthesis of a pigmentary complex of sprout in a saccharose solution, imitating lack of moisture. Ability of different varieties to adapt to the harmful environmental conditions is determined by its genotype. Depending on genotype, negative impacts of drought stress on plant are different: more tolerant are characterized by low level of sensitivity to stress. During the extreme tension of drought the varieties of G. hirsutum L. and G.

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barbadense L. differently response to the stress. This difference allowed us to classify varieties into the groups with different level of resistance: resistant, moderately resistant, less resistant and susceptible. Selected resistant cotton varieties have a perspective for being used in a breeding practice for obtaining new economically valuable forms. These varieties are characterized either by lack of stress depression of physiological indicators or insignificant level of these indicators. The different percentage ratio of resistance level between the varieties of G.hirsutum L. and G. barbadense L. species was observed. The varieties of G. barbadense L. were more tolerant to the abiotic stress factors. From total accession of G. barbadense L. 40.5% was resistant, 11,4% moderately resistant, 26.6% less resistant, 21.5% susceptible. As for G. hirsutum L. 11.4% accessions were estimated as a resistant, 12.1% moderately resistant, 27.9% less resistant and 48.6% susceptible.

P 6.27 - Rice farnesyl transferase inactivation improves drought tolerance and root growth Manavalan L.P.1, Chen X.2, Clarke J.2, Salmeron J.2, Zinselmeier C.3, Nguyen H.T. 1

(nguyenhenry@missouri.edu)

1 Division of Plant Sciences and National Center for Soybean Biotechnology, University of Missouri, Columbia, MO 65211, USA;

2 Syngenta Biotechnology Inc, Research Triangle Park, NC 27709, USA; 3 Syngenta Seeds, Slater, IA 50244, USA. About one third of the world’s rice area is in rainfed lowlands and mostly prone to drought. Identification of genes and regulators imparting drought tolerance in rice is an attractive strategy to engineer not only rice but other cereal crops with improved drought tolerance traits. We demonstrate that RNAi-mediated disruption of expression of a rice farnesyl transferase gene improves drought tolerance both at vegetative and reproductive stages. Twenty-day old seedlings of wild type (Nipponbare) and ten independent events of transgenic RNAi lines showed no difference in morphology. When subjected to water deficit for a period of 25 days under growth chamber conditions, transgenic plants showed delayed wilting and improved recovery. When five independent events, along with wild type plants were subjected to drought at the reproductive stage (at d=0, when inter auricular distance between flag leaf and penultimate leaf is zero) under greenhouse conditions, the transgenic plants lost water slowly compared to the wild type, through reduced stomatal conductance and retention of high leaf relative water content (RWC). After 28 days of slow progressive soil drying, transgenic plants recovered better and flowered earlier than wild type plants. The yield of water stressed transgenic plants ranged from 5 to 39% higher than wild type plants. When grown in plates containing Yoshida’s nutrient solution and 1.2% agar, transgenic positives from three independent events showed increased root length and enhanced number of lateral roots. In contrast to a previous report in Arabidopsis where mutant of farnesyl transferase seeds showed enhanced drought tolerance through ABA sensitivity, and reduced stomatal conductance, the RNAi-mediated inactivation rendered ABA insensitivity in rice transgenics compared to wild type (WT) and reduced stomatal conductance.

P 6.28 - The prospect of combining resistance to Stiga hermonthica with tolerance to drought in maize Menkir A. (a.menkir@cgiar.org), Badu-Apraku B., Adepoju A. International Institute of Tropical Agriculture. Stirga hermonthica poses the greatest threats to maize production in the savannas of West and Central Africa (WCA). The impact of Striga is severe on crops wreaked by drought and suboptimal soil nitrogen, which are common in marginal production zones in this region. Rapid population growth in rural WCA has increased pressure on farm land availability, forcing farmers to produce their crops in marginal production zones with poor soil fertility and severe drought stress. Land use intensification has also contributed to serious land degradation and poor water holding capacity of the soil, which exacerbate the problem of drought stress. Thus drought frequently occurs in maize production fields that are infested with S. hermonthica in WCA. A breeding strategy to improve

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performance of maize in the savannas should thus emphasize on the development of cultivars having tolerance to drought and resistance to the parasite. As a short-term breeding strategy, we screened diverse maize inbred lines having resistance to S. hermonthica for drought tolerance under controlled stress imposed by withdrawing irrigation from four weeks after planting to harvest. Promising Striga resistant inbred lines selected for drought tolerance were used for developing synthetics and hybrids. A trial composed of top-cross hybrids formed by crossing the resulting synthetic as a female parent and promising Striga resistant inbred lines selected under drought stress as male parents was evaluated under controlled drought stress, optimum growing conditions, and artificial S. hermonthica infestation in multiple locations in Nigeria in 2008. The difference among these hybrids was significant for grain yield in each of the three growing conditions notwithstanding the presence of significant location x hybrid interactions. In the first trial, the top 10 hybrids produced 90% to 137% more grain yields than a commercial top-cross hybrid check (Oba 98) under controlled drought stress. These promising hybrids out-yielded Oba 98 by 12% to 48% under optimum growing conditions and by 539% to 789% under artificial infestation with S. hermonthica. They also sustained lower Striga damage symptoms and supported fewer emerged parasites in comparison with Oba 98 under S. hermonthica infestation. These results suggest that a potential exists to combine resistance to the parasite with drought tolerance in a single hybrid without compromising desirable performance under favourable growing conditions. However, deliberate breeding effort will still be needed to develop maize hybrids and synthetics that combine much higher levels of resistance to Striga and tolerance to drought.

P 6.29 - Genetic analysis of performance of maize (Zea mays L.) inbred lines under managed drought stress Meseka S.K.1 (kayidriyewa@yahoo.com), Menkir A.2, Ibrahim A.E.S.3

1 Agricultural Research Corporation, P.O. Box 126, Wad Medani, Sudan; 2 International Institute of Tropical Agriculture, Oyo Road, PMB 5320 Ibadan, Nigeria; 3 Faculty of Agricultural Sciences, University of Gezira, P.O. Box 20, Wad Medani, Sudan. Drought stress causes significant yield reduction in maize (Zea mays L.) in sub-Saharan Africa. Understanding the inheritance of drought tolerance would be useful in developing drought tolerant hybrids and synthetics. The objectives of our study were to determine the (i) effects of drought susceptible and tolerant parental lines on the performance of their hybrids groups of susceptible x susceptible, susceptible x tolerant and tolerant x tolerant, (ii) mode of inheritance of tolerance to drought, and (iii) relationship between per se performance of the parents and their hybrids. A Design II mating scheme was used to evaluate the combining ability of 24 maize inbred lines with contrasting responses to drought stress. The parental lines and 96 F1 hybrids were evaluated in separate trials side by side under severe and mild drought stress as well as under well-watered conditions in Nigeria between 2002 and 2005. Inbred lines with large ear leaf area and high chlorophyll content were more tolerant and had higher grain yield than lines with small ear leaf area and low chlorophyll content. Most of the crosses with at least one tolerant parent produced tolerant hybrids, whereas most crosses between susceptible lines generated susceptible hybrids. Both general (GCA) and specific (SCA) combining abilities were significant ( p < 0.01), with GCA accounting for 55 to 87% of the total variation in all the traits, except number of ears per plant under mild drought stress. Both additive and non-additive genetic effects conditioned grain yield and number of ears per plant under drought stress and well-watered conditions. Other traits were controlled mainly by additive genetic effects under both stress and non-stress conditions. Mid-parent values were useful predictors of hybrid performance for all traits. Inbred line KU1409, 1824, 9006, 9432 and (TZMI501×KU1414×501) with positive and significant GCA effects for grain yield under drought stress may be used as parents for developing maize hybrids that combine tolerance to drought with high yield potential.

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P 6.30 - Farmer participatory cassava breeding under drought prone environments in Tanzania Mkamilo G.

1(geoffreymkamilo@yahoo.co.uk), Masumba E.1, Kimata B.1, Kulembeka H.1, Kanju E.2

1 National Root and Tuber Crops Research Program, Agricultural Research Institute (ARI) Naliendele

P.O Box 509 Mtwara, Tanzania; 2 International Institute of Tropical Agriculture (IITA), P.O. Box 6226 Dar-Es-Salaam, Tanzania. Tanzania is the fourth largest producer of cassava in Africa with national average fresh roots yield is about 8 t ha-1, which is well below the continent’s average of 10 t ha-1. Low yield is mainly caused by abiotic stresses (low soil fertility and drought) and susceptibility of commonly grown varieties to biotic stresses such as cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). To address this yield gap, the national cassava breeding program has been conducting farmer participatory evaluation of cassava genotypes in Southern, Eastern and Central regions of the country; the drought prone environments. Of 110 clones evaluated at Preliminary Yield Trials in 2008, only 14 clones were selected for further evaluation in Southern region, 16 for Eastern region and 25 for central region. These clones were selected due to their high fresh roots yield under drought prone environments. Other selection criteria were high dry matter content, field resistance to CMD and CBSD, and farmer preferences.

P 6.31 - Phenotypic characterization of selected local maize landraces for drought tolerance based on stress at flowering in Kenya Munyiri S.W.1 (wanja_munyiri@yahoo.co.uk), Pathak R.S.2, Tabu I.M.2 1 Makerere University, Faculty of Agriculture-CAEC, P.O. Box 7062, Kampala, Uganda; 2 Egerton University, Department of Crops, Horticulture and Soils, P.O. Box 536, Njoro, Kenya. The demand for more food culminating from the population increase and the migration of people from high potential areas to semi arid lowlands has led to maize growing in marginal areas in Kenya. Maize local landraces are an important livelihood resource in these areas. The objective of the study was to phenotypically characterize selected Kenyan local maize landraces for drought tolerance. In experiment I, 64 genotypes consisting of 39 local landraces randomly selected from the gene bank of Kenya, 17 inbred lines from Kenya Agricultural Research Institute (KARI), 7 inbred lines from CIMMYT and a dry land Composite check were grown under irrigation (unbalanced lattice design). The genotype’s days to anthesis were determined and ranged between 35 and 64 days under optimum conditions. Based on anthesis silking interval (ASI), 25 genotypes representing all the groups were selected for drought stress evaluation. In experiment II, the 25 genotypes were stagger-planted to synchronize flowering in order to impose stress at a uniform stage of development. Moisture was withheld 2 weeks before anthesis in the stressed plots and stress maintained for 40 days. Both experiments were conducted at semi-arid zones of Kenya and replicated three times. The check variety which is widely grown in marginal environments attained tassel anthesis earliest (35-40 days) but had a long ASI (12 days), exhibiting drought escape mechanisms rather than tolerance. One inbred line from KARI-Kitale (high altitude zone) unexpectedly exhibited drought tolerance characteristics. Genotypes CML-265 and CML-492 exhibited tolerance to drought, but 2 of the 17 KARI inbred lines were even better. The lowest% yield loss was in a coastal local landrace from a drought prone area. Anthesis silking interval, leaf rolling and plant height correlated to yield under stress. Anthesis silking interval under well-watered conditions was not correlated to yield although plant height was. Grain yield was significantly correlated to shelling%, ears per plant and plant height but negatively correlated to days to silking, ASI and leaf rolling. An increase in number of ears per plant, 100-seed weight, increased plant height, high shelling%, reduced leaf rolling and low ASI were associated with improved grain yields under water stress. Yield components that were affected by drought resulting in grain yield losses were the number of ears per plant, shelling%, kernel weight and plant height. Several local landraces originating from the marginal zones exhibited drought tolerance owing to their adaptability to moisture-prone conditions.

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P 6.32 - Improvement of local lentil variety for drought tolerance and high yielding using diallel crossing method Naji M.Z. (naji_zaid2006@yahoo.com), Mohammed A.M., Talal M.O. Agricultural Research & Extension Authority Northern Highlands Research Station Sana'a Yemen. Most of local lentil varieties grown in Yemen are microsperma, low yielding, and early maturing. Therefore the aim of the study was the improvement of local lentil variety (Balasn) to drought tolerance and high yielding. Four parents of lentil {(tow microsperma Balasan ,and 76TA And tow macrosperma Precoz, and Flip 84-14L)} were crossed using the diallel crossing method in 2000 Summer season. Six hundred seeds from each hybrid were planted in tow replications to estimate heritability percentage and forty eight individual plants were selected based on plant type, early maturing and increased of branches/plant number of pods/plant, number of seeds/plant. The best selected hybrids were compared with the parents, and the advanced elected lines incorporated into a preliminary yield trail in 2005 summer season at Northern Highlands Research Station Sana'a Yemen. These seven hybrids along with the best common local variety were put into a yield trail in 2006 Summer season at three different agro ecological regions (Kohl an affar,Kukaban,and Bane-matter). Obtained results indicated that most of type hybrids showed earliness. Whereas the H.B-3 hybrid has increased number of branches/plant, number of pods/plant and number of seeds/plant than the local check. Results also revealed that the H.B-3, and H.B-2 produced high seed yield/area with percentage of (74.3, and 58%) respectively over local check.

P 6.33 - Breeding maize varieties for drought tolerance in Malawi Nhlane G. (g.nhlane@malawi.net) Chitedze Research Station, P.O. Box 158, Lilongwe, Malawi Maize is one of the main cereal crops in Malawi and plays an important role in farmer’s lives and on farm income. However, yield is low with drought and low soil fertility among the principal factors influencing maize production. The development of drought tolerant cultivars represents an important method for reducing the effect of drought stress on maize production. The maize breeding program developed a screening site in order to develop maize varieties with drought tolerance during the flowering period when maize is very sensitive to stress. Several populations, and hybrids were evaluated for yield potential and other agronomic characteristic under artificial conditions. Several varieties were selected and released and these are ZM621, ZM521 ZM 623, ZM721, ZM 305, ZM 523, Matindiri, Sundwe and ZM421. These cultivars had shown good performance and production stability in low rainfall areas, showing the potential for improving the performance of maize under conditions of water stress through plant breeding. These varieties were also put under multilocation testing using the mother and Baby concept. In cooperation with NGO’S and Extension and farmers, seed production of these varieties was done and the varieties are grown widely in Malawi .In future, our drought program will get increased attention with the objectives of adapting high yielding germplasm to stress conditions to develop inbred lines tolerant to drought identify hybrids and open pollinated varieties with broad adaptation to highly variable growing conditions in Malawi.

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P 6.34 - Comparison of farmers and breeders field selection for agronomical performance in Mediterranean durum wheat Nsarellah N.1(nsarellah@yahoo.com), Tuberosa R.2, Sanguinetti M.C.2, Amamou A.1, Ouabbou H.1, Nachit M.3 1 Dryland Center, Institut National de la Recherche Agronomique, B.P.589, Settat, Morocco; 2 University of Bologna, Dept. of Agro-env. Sciences and Technology. Via Fanin 44, 40127 Bologna, Italy; 3 International Center of Agricultural Research in Dry Area, ICARDA, Aleppo, Syria. Breeding has brought about many improvements in field crops yield, adaptation and quality. However, adoption of the modern varieties has not always been optimum even if they were highly performing and stress tolerant. Farmer participation has been suggested and implemented in many programs. According to this approach, Breeder can improve the adoption of their releases by incorporating farmer selection. The objective of this study is to compare the selection made by farmers and breeders in respect to several plant traits and field performances. Forty five accessions and varieties adapted to different parts of the Mediterranean region were grown in Morocco in three block experiments under partially irrigated and Rainfed regimes. A panel of breeders and two panels of farmers scored their choice of the genotypes in the three blocks and in both water regimes. The scores were compared in terms of variation and ability to discriminate between the effects of water regimes and genotypes. A comparison of the correlation between visuals scores and traditional measured traits was performed. Although the distribution of selection scores was different between farmers and breeder, all scores were significantly correlated to most traits related to yield, morphology and phenology. The data indicated that farmers scoring ranged from incoherent to as accurate as that of the breeder. Field selection was well correlated to agromorphological characterization within water regimes. And field selection was highly correlated to agromorphological characterization across water regimes. These data indicate that farmer selection could be accurate enough to help select well performing varieties that respond to phenological preferences of users.

P 6.35 - Genetic studies on breeding faba bean for drought tolerance: 3 - drought suceptibility index Omar S.A.1 (said_omar1959@yahoo.com), Belal A.E.F.H.2, El-Sarag E.I.2, Hassan A.I.1, El-Metwally M.A.1

1 Plant Breeding Unit, Plant Genetic Resources Dept., Desert Research Center, Cairo, Egypt; 2 Plant Production Dept., Faculty of Environ. Agric. Sci., Suez Canal University, El-Arish, Egypt. Plants encounter a wide range of a biotic stresses, including drought, cold, and salt etc., selection physiological characteristic and evaluation the performance and degree of a biotic stresses (drought tolerance) of the six selected faba bean cultivars and their F1 crosses tested under two levels of soil humidity during the two growing seasons 2006/07,2007/08 at North Sinai Research Station, Desert Research Center. The obtained results could be summarized as follow: Genotypes mean squares for drought susceptibility index (DSI) were significant for seed yield, no. of pods/plant and no. of seeds/pod. Of all hybrids, the crosses Nubaria 1(P1) × Giza 716 (P5) had the best DSI of stress irrigation for number of pods/plant. While, Sakha 1(P3) × Giza 716 (P5) had the highest tolerance for stress irrigation for no. of seeds/pod. Also, the crosses Sakha 2 (P2) × Giza 2 (P6) followed by Sakha 2 (P2) × Giza 716 (P5), Giza 429 (P4) × Giza 2 (P6) and Sakha 2 (P2) × Sakha 1(P3) for seed yield/plant gave the best desirable DSI to drought resistance. The cross Sakha 1(P3) × Giza 429 (P4) expressed significant positive heterotic effects relative to better parent value for number of seeds/pod and seed yield/plant respectively. The best combination was the cross Sakha 1(P3) × Giza 429 (P4) for DSI of seed yield and number of seeds/pod. Application of yield and two of its components based on drought susceptibility index (DSI) indicated that the parental variety Nubaria1 (P1) gave the desirable drought susceptibility index (DSI) for number of pods/plant. On the contrary it gave the lowest DSI for number of seeds/pod.

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P 6.36 - Breeding for water-limited environments: ecophysiological and agronomical traits of 24 durum wheat genotypes under semi-arid climate in Morocco Outoukarte I.1, Aouame L.E.1, Boumaalif O.1, Price A.2, Nasrelhaq N.3, Labhilili M.4, Hadrami I.E.1

(hadrami@ucam.ac.ma)

1 Laboratoire de Biotechnologies, Protection et Valorisation des Ressources Végétales, Université Cadi Ayyad, Faculté des Sciences Semlalia, BP. 2390, 40 000, Marrakech-Maroc;

2 Institute of Biological and Environmental Sciences, University of Aberdeen, UK; 3 Institut National de la Recherche Agronomique, Settat, Maroc; 4 Institut National de la Recherche Agronomique, Rabat, Maroc. In Morocco, like in other Mediterranean countries, drought remains as one of the most limiting factors concerning the crop productivity particularly in cereals. A comparative study of growth and development of 24 durum wheat genotypes was carried out in open field, in pots and in rhizotrons system in order to select the most suitable cultivars to be cultivated under arid and semi-arid regions. Some of these genotypes were characterized by their root distribution in the field and the others were described in many studies by their adaptation to other different environments. Several characters such as the above flag leaf node traits, plant height, tillering degree, leaf rolling, leaf posture, chlorophyll content, stomatal resistance and flowering time were analyzed and compared. Correlation analysis showed that spike size was positively correlated with sheath length and with leaf length in field, rhizotrons and pots experiments. However, this trait was negatively correlated with peduncle length. In rhizotron experiments, genotypic variability was revealed in term of maximum root angle and root biomass partitioning at different depths and the character root/shoot length ratio was negatively correlated with sheath, spike and flag leaf length. Under drought stress conditions in pots, flag leaf length and peduncle length were the most affected traits. Regarding the life cycle period, the earliest flowering genotypes exhibited high leaf posture and degree of leaf rolling. In addition, important genotypic variability was revealed also in term of stomatal resistance, frequency and their form under field conditions.Variance and multiple comparisons analysis revealed that sheath dry weight, peduncle, sheath and spike lengths are the morphological traits giving maximum differences between genotypes. The integration of these morphological data with other ecophysiological parameters related to drought stress will provide useful information on the wheat production potential and may be used as tools in wheat breeding programs to mitigate the effect of drought under Mediterranean regions. In addition, the results obtained here will be exploited for detecting QTLs and associated molecular markers related to ecophysiological and agronomical traits determining yield in Durum wheat.

P 6.37 - Diversity analysis for morphological and seed traits under rainfed situation involving minicore subset in groundnut (A. hypogaea) Parameshwarappa K.G. (ssoparamesh@rediffmail.com), Kenchanagouda P.V., Madhura C. All-India Co-Ordinated Research Project (Groundnut), MARS, University of Agricultural Sciences, Dharwad -580 005, Karnataka, India. The minicore subset comprising 182 accessions from Virginia bunch, Virginia runner Spanish bunch and Valencia were evaluated for ten morphological and ten agronomical traits along with nine released varieties to estimate phenotypic diversity using Principal Component Analysis and Hierarchical Cluster analysis. The varieties Jl-24, Dh 86 and TAG 24 were released at the All India level and possess relatively better mid and end of season drought tolerance when grown during rainy season. The results revealed that all the ten characters except growth habit and pod constriction contributed to multivariate polymorphism. The Hierarchical Cluster analysis revealed eight distinct clusters at the distance of 10 indicting the considerable genetic diversity. Thus due consideration could be given to botanical types as well as accession within clusters for isolation of parents in hybridization programme. The potential accessions for multiple traits have been identified from different habit groups viz., test weight, oil content, sound mature kernels. The traits shelling percent, days to maturity, resistance to leaf spot, rust and Sclerotium resistance were noticed in accessions ICG 5662, ICG 14475 and ICG 14482 from Virginia bunch ICG

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2857 and ICG 12672 in Virginia runner. The accessions ICG 11651 and ICG 13603 from Spanish bunch and ICG 5609 and ICG 12625 from Valencia were elite entries for array of traits. These elite germplasm can be utilized for hybridization with drought tolerant varieties for enhancing productivity of groundnut underfed conditions.

P 6.38 - Identification of transgressants with premium quality and productivity under aerobic condition Patil K.G.1,2, Gowda R.P.V.1,3, Shashidhar H.E.1, 2 (heshashidhar@rediffmail.com), Kulkarni R.S.1 1 University of Agricultural Sciences, Bangalore, India; 2 Barwale Foundation, Hyderabad, India; 3 International Rice Research Institute, Philippines. Rice is a predominant staple crop for more than 2.5 million people. Drought is one of the main environmental factors that cause a substantial reduction in rice production. Development of drought-resistance varieties with a higher yield potential is one of the major objectives of breeding programs for rainfed areas of rice. Several breeding methods are being used to develop such drought resistance varieties. Recombination breeding is one of the important method to incorporate and get the favorable quantitative and qualitative traits of both the parents in its progenies. Hence, two mapping populations were developed and evaluated under aerobic condition at the Department of Genetics and Plant Breeding, University of Agricultural Sciences, Bangalore during Kharif 2007. IRRI 38, an early drought resistance line crossed with Jeerige sanna, a local aromatic upland variety. In the F2 generation, 20 recombinant plants having 62-200 percent superiority over better parent for yield were identified. Among them, many recombinant plants were having superior premium quality parameters. Similarly, another population was developed using ARB6, an outperforming breeding line under severe stress condition in multilocation trials of IRRI- India drought network program and Jeerige sanna. The variations for grain yield per plant among the progenies were 7 to 99 gm/plant. Fifteen recombinant plants have shown a minimum of 8-204 percent increase in yield over its better parent under aerobic condition. GCV and PCV for most of yield related traits were high in both the populations, indicating the amount of variability generated. The correlation and path analysis studies revealed a significant positive association of grain yield /plant with number of productive tillers per plant, number of grains per panicle and plant height. The favourable transgressive segregants identified for high yielding ability in F2 generation of both the crosses are being advanced to further generations to identify stable genotypes suitable for cultivation under limited water conditions.

P 6.39 - Response of productive sugarcane selections to water limited conditions Patil S.B.1 (sbp_ars@rediffmail.com), Patil B.C.2, Tippannavar P.S.3

1 Agricultural Research Station, Sankeshwar- 591 314, India; 2 Agricultural Research Station, Dharwad – 580 007, India; 3 Krishi Vignyan Kendra, Saidapur Farm Dharwad – 580 005, India. Drought is one of the major constraints causing drastic decline in sugarcane production. Suitable technological interventions are needed to sustain production of sugarcane to meet the domestic and export demands of sugar. Development of productive genotypes tolerant to moisture stress assumes greater importance in this context. Sugarcane yield under stress is function of genotype’s response to stress and the yield potential. Hence, promising selected productive clones and four commercial varieties were studied for their response to moisture stress during critical water demand period (formative phase). Pre-selected clonal population exhibited significant variability for most of the sugar and cane yield contributing traits under normal irrigated and moisture stress environments. Mean values for cane yield, sugar yield and their component traits were lower in moisture stress than normal irrigated environment. The range was widened under moisture stress for most of the cane yield component traits compared to juice quality traits indicating considerable scope for genetic enhancement of cane productivity under moisture stress. The extent of reduction in the mean values due to moisture stress over normal irrigated for juice quality traits were significantly lower compared to cane yield contributing traits indicating their stability. Significantly higher reduction in number of tillers compared to number of millable canes reveals ability of productive genotypes

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to mitigate moisture stress through maintenance of economic level of tillers with improved conversion potential in to millable canes. Two clones viz., CoSnk 05104 and CoSnk 03632 showed an increase in sucrose content under water stress while, three clones viz., CoSnk 05101, CoSnk 03044 and CoSnk 08101 recorded increase in number of millable canes indicating contribution of these traits towards improved sugar and cane productivity under water deficit conditions which could be attributed to the improved rejuvenation capacity of genotypes after relief from stress. Identified productive clones could be suitably exploited for genetic enhancement of productivity through commercial cultivation and inclusion in the current breeding programs.

P 6.40 - Microsatellite markers associated with drought resistance in rice (Oryza sativa L.) Poornima R., Salunkhe A.S., Suji K.K., Amudha K., Prince K.S.J., Senthil A., Babu R. C. (chandrarc2000@yahoo.com) Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology, Tamil Nadu Agricultural University, Coimbatore, India. Water stress is the serious limiting factor that reduces rice production and yield stability in rainfed ecosystem. The major breeding objective in these ecosystems is to improve drought resistance of rice plants but, little progress has been achieved in improving yield under stress due to the poor knowledge of the genetic control of drought resistance. Yield improvements under drought stress can be achieved by selecting for secondary traits contributing in drought resistance in a breeding program. However, phenotypic selection for such traits is labour-intensive. Molecular marker technology serves as a tool for selecting such complex traits and allows breeders to track genetic loci controlling drought resistance traits, without having to measure the phenotype, thus reducing the need for extensive field testing over space and time. However, marker assisted genotyping of large mapping population is tedious and time consuming. Alternatively, selective genotyping strategies have been proposed. Bulk Segregant Analysis (BSA) is one such strategy in which the process of genotyping aids in reducing the sample size to two DNA samples by grouping plants according to their high or low expression of a particular trait. In this study, 10 drought tolerant and 12 drought susceptible recombinant inbred lines (RILs) developed from a cross between IR20/ Nootripathu were selected based on drought scores (leaf rolling and leaf drying) under water stress. A total of 135 rice microsatellite primer pairs were used for screening parents and 36 primers were found to be polymorphic. The drought resistant and susceptible bulks were screened using these polymorphic primers and RM 3215 was found to be polymorphic between the bulks and co-segregated among all the RILs constituting the respective bulks. The marker RM 3215 has been mapped on chromosome 8 of rice and found to be linked to various drought resistance traits which may be useful for marker assisted breeding (MAB).

P 6.41 - Association of N2 fixation and transpiration efficiency of peanut genotypes under early season drought Puangbut D., Jogloy S. (sanun@kku.ac.th), Vorasoot N., Akkasaeng C., Patanothai A.

Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Muang, Khon Kaen 40002, Thailand. Transpiration efficiency (TE) has been well established as drought resistance traits in peanut. Although studies on the surrogate traits for TE in peanut have been reported in several physiological traits, the relationship of TE with N2 fixation has not been well understood. The objective of this study was to investigate the relationships between TE and N2 fixation under early season drought. Two field experiments were conducted during June to October 2005 and December 2005 to April 2006 at the Field Crop Research Station of Khon Kaen University, in Khon Kaen province of Thailand. A split-plot design with four replications was used with main-plots consisting of two watering regimes i.e. fully-irrigated control and maintaining at 1/3 available soil water from emergence to 40 days after emergence followed by adequate water supply, and sub-plots consisting of 12 peanut genotypes. Data were recorded for specific leaf area (SLA) and SPAD chlorophyll meter reading (SCMR) at 40 day after emergence and TE and N2 fixation at harvest. Early season drought increased SCMR, TE and N2 fixation but it reduced SLA. Strong and more consistent variation for TE was observed among 11 peanut genotypes across seasons. Across both

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seasons, ICGV 98300, KK 60-3 and Tifton-8 had high TE and also had high N2 fixation under drought conditions. KK 60-3 and Tifton-8 had low SLA and high SCMR under early season drought conditions. Under early season drought, TE was strong and positive correlated with N2 fixation. N2 fixation had a contribution to TE under well-watered and drought conditions, especially under drought condition. SCMR and SLA had smaller contributions to TE under well-watered and ESD conditions. From this study it was apparent that N2 fixation was an important trait for TE under early season drought.

P 6.42 - Sahyadri (KST28) A high yielding drought tolerant and quality FCV tobacco (Nicotiana tabaccum L.) variety for Karnataka light soils region Rangaiah S.(srangaiah@rediffmail.com), Rangaswamy B.R., Nataraju S.P., Vageesh T.S., kumar M.D., Karegowda C., Ravindra H. All India Network Research project on Tobacco, ZARS, Navile, Shimoga-577 204, Karnataka, India Flue cured Virginia Tobacco (FCV) is an important commercial crop of India. Karnataka State of the country ranking first for area and second for the production of this crop. Further, the FCV tobacco produced in this state is known for its exportable quality especially for its superior filler type quality. The average yield of the state is as 1200 kg/ha compared to the national average 1800 kg/ha. One of the reasons for this low yield is lack of proper distribution of rainfall resulting in intermittent and long drought periods, the other reason being susceptibility to black shank disease and root knot nematodes of the present recommended varieties viz; Thrupthi and Bhavya. Yield potential of these two varieties though is on the higher side is not as high as some of the varieties developed in other states. There is thus need to identify/develop new varieties with potential for higher yield. In spite of intermittent drought periods and tolerance/resistance to black shank and root knot nematode. Efforts made at this station from 2001 have resulted in developing a new variety Sahyadri (KST 28). It is developed through selection after hybridization; the parents involved being KST19 and VA 145 Its average cured yield is 2300 kg/ha, which is 15% higher than the present recommended variety Thrupthi. As the segregating populations from which this genotypes was selected was exposed to intermittent drought periods based on this yield potential and the drought resistance parameters recorded, it can be considered as a drought resistant variety. It showed consistency in its moderate level of resistance to black shank unlike Thrupthi and Bhavya. Its level of resistance to nematode was distinctly higher as compared to the two checks. It was on par with the checks for resistance to all other usual pests and diseases and for quality characters. Proposal to release this variety as an improvement over the two present recommended varieties was accepted by the State Variety Release Committee (SVRC) in its meeting held during October 2008 and released to the cultivation for the entire state. It is sure to boost the average FCV production yield of the state and contribute to the improvement in the economy of the FCV Tobacco farmers of the state.

P 6.43 - Screen of durum wheat lines for drought tolerance Rashidi V.1(rash270@yahoo.com), Nofouzi F.2, Tarinejad A.3

1 Faculty of Agriculture, Islamic Azad University, Tabriz Branch, Iran; 2 Islamic Azad University- Tabriz Branch, Iran; 3 Faculty of Agriculture, Azarbayjan Tarbiat, Moallem University, Iran. In order to study of drought tolerance in durum wheat lines for some traits and also to determine the high yielding and promising genotypes in durum wheat, two separate experiments was conducted in simple lattice designs that each with 49 genotypes including 43 exotic and 6 local genotypes. This experiments was performed in research station of Tabriz Islamic Azad University in 2006. In one experiment irrigated commonly to physiological maturity, but in another experiment exerted drought stress in 3 phonologic steps (tillering, anthesise and grain filling) by did not irrigate. Combined analysis of data showed a high significant difference among genotypes for all traits. This indicates that there is genetic diversity in durum wheat for the traits studied. Also interaction of genotype* environmental significant for yield, number of seed per spike and 1000 seed weight, that explanatory different behavior of durum wheat for upon traits in different environmental conditions. Lines of 27 (Aramides), 49, 44 and

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47 (Yazlig) had high yield in both condition. Superior lines in non stress condition for number of seed per spike was 2, 34 and for 1000 seed weight was 16, 38; also superior lines in drought stress condition for number of seed per spike was 21, 43 and for 1000 seed weight was 16 and 25. Correlation of traits in drought condition and potential condition showed that, grain yield had high correlation with plant height, spike length, peduncle length, number of tiller, harvest index and number of seed per spike. Estimate of drought tolerance indices include STI, GMP and HAR showed that the line of 27(Aramides) was tolerant.

P 6.44 - Effect of environment on the combining ability of virginia tobacco genotypes Sadeghi S.M.1 (smsadeghi55@yahoo.com), Samizadeh H.2

1 Islamic Azad University Lahijan branch, Lahijan, Iran; 2 Faculty of Agriculture, University of Guilan, Iran. To determine the impact of environment on the combining ability of Virginia tobacco five genotypes were crossed in a half diallel fashion and the resulting material was grown under irrigated as well as drought stress conditions. Data collected on yield and related traits revealed highly significant differences among genotypes under both sowing conditions. Combining ability analysis revealed that specific combining ability (sca) were highly significant for all the traits and the general combining ability (gca) effects were highly signification for all the traits except the dry leaf yield both sowing conditions. The results, showed that the additive variance had important role in controlling of number of leaves, width of leaf and leaf area index in both conditions, while, for dry leaf yield, non additive gene effect played major role. In stress conditions, the additive and dominance variances were involved together in plant height, but in non stress condition the dominance variance was more important than additive variance.

P 6.45 - Wheat and barley breeding for drought tolerance in Yemen Saif A.A.(a_w_s_mozaid@yahoo.com), Al-Shamiri A., Abdulhasib A.

Agricultural Research & Extension Authority, Alhasabah Street, P.O. BOX 4721 Yemen. Yemen is considered as one of the oldest agricultural civilization in the world. The total arable land is estimated to be 1,663,858ha. Irrigated land is about 565,385 ha. (45%of the total arable land ). The country is divided into three major agro-ecological zones depending on the elevation at the sea level and annual rainfall. The major water resources in the country are rainfall, underground water and seasonal springs. Yemen is facing a major challenge of water shortages and thereby it is highly desirable to change the selection criteria of yield per unit area to yield per unit of water used. Now our top priority is to develop drought resistant varieties in breeding research programs of the country. In order to address our agricultural constraints, we started a breeding program of wheat and barley with farmer participation in rainfed condition where it was noticed sharp deterioration of barley and wheat growing areas that reflects the fluctuation of rainfall rates and its regularity. The main objective was to improve the local cultivars and develop improved varieties early maturation, lodging resistant and drought tolerance with reasonable yield. This study will be summarized the results of three years screening of barley and wheat cultivars under limiting water stress in the research farm and farmer's field for drought tolerance. Twenty four of both barley and wheat lines including the check were used in this study. These cultivars were received with collaboration with similar programs running in the regional and world level, they were planted in the research farm belong to the Northern high land research station in Sana'a during 006 season under limiting irrigations and farmers field during 007 and 008 seasons under rainfed condition in three locations which belong to three governorates; Hajaa governorates, Sana'a governorates and Al-Mahweet governorate. Randomized Complete Block Design (RCBD) was used with four replications. Evaluation was done for earliness to avoid drought phenomenon that occurred frequently, leaf ruling, leaf color and grain and biological yield. Result shown, superiority of two cultivars PByt. 9-006 and PByt. 7-06 for barley and Pwyt -17-2006 and Pwyt -10-2006 for wheat in compression with the others including the checks. These promising cultivars of both crops will be multiplied their seeds and disseminate to the farmers.

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P 6.46 - Microsatellite markers linked to drought resistance in rice (Oryza sativa L.) Salunkhe A.S., Poornima R., Suji K.K., Amudha K., Prince K.S.J., Senthil A., Babu R.C. (chandrarc2000@yahoo.com) Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology, Tamil Nadu Agricultural University, Coimbatore, India. Developing rice cultivars with inherent capacity to withstand drought stress would help to stabilize rice production especially in rainfed ecosystems. Conventional breeding is slow in attaining progress due to poor understanding of genetic control of drought resistance. Identifying genomic regions contributing to drought resistance will help to develop rice cultivars suitable for rainfed regions through molecular marker-assisted breeding. Molecular markers help in identification of Quantitative Trait Loci (QTLs) associated with drought resistance traits and their indirect selection using marker assisted selection (MAS). Identification of DNA markers associated with drought tolerance is usually carried out by genotyping of large mapping populations, which has been difficult being labour-intensive, time consuming and cost-ineffective. Alternatively, bulked segregant analysis (BSA) serves as a valuable approach for rapid identification of markers associated with drought resistance by genotyping only the extreme phenotypes rather than whole population. In this study, 10 drought tolerant and 12 drought susceptible recombinant inbred lines (RILs) developed from the cross IR20/Nootripathu were selected based on drought scores under water stress. A total of 140 rice microsatellite primer pairs were used for screening parents and 26 primers were found to be polymorphic. The drought resistant and susceptible bulks were screened using these polymorphic primers and three were found polymorphic between bulks. Out of the three polymorphic primers, RM8085 co-segregated among all the RILs constituting the respective bulks. RM8085 on chromosome 1 has been reported to be linked to several drought resistance traits and may be useful in marker assisted breeding (MAB) for drought resistance in rice.

P 6.47 - Deeper root length and grain yield inheritance as a possible tool for drought tolerance in durum wheat (Tritium durum Desf.) Sayar R.1, Khemira H.2, Bchini H.3(houcine.bchini@gmail.com) 1 National Institute of Agriculture research of Tunisia (INRAT), Kef Research Station, 7119 Boulifa le Kef,

Tunisia; 2 Faculty of Sciences of Gabès, University of Gabès, Zrig Gabès 6072, Tunisia; 3 Physiology Lab., National Institute of Agriculture research of Tunisia (INRAT), Elafareg Research

Station (Beja), Tunisia. Inheritance, heterosis and combining ability of deeper root length (DRL) and grain yield (GY) were investigated in durum wheat populations obtained from half-diallel crossings among five parental lines differing in their DRL and GY. The study was conducted with the final objective of identifying parent lines to be used in a breeding programme to develop drought-tolerant wheat varieties. General combining ability and specific combining ability effects were significant for both traits; however, additive gene effects were predominant over nonadditive effects. Partial dominance was ambidirectional for DRL and unidirectional for GY. Lines INRAT69 and Omrabia conferred DRL whereas Omrabia and Khiar transmitted high GY to their respective progenies. In the studied material, both characters were controlled mainly by dominant alleles, but they could also be attributed to recessive alleles although less frequently. Both broad-sense and strict-sense heritabilities were high for DRL, confirming the importance of additive gene effects, whereas strict-sense heritability for GY was average, indicating the importance of interaction effects as compared with the additive effects; this could mean reduced selection efficiency for the latter trait. Thus, the expected genetic progress per cycle of selection will be lower for GY compared with DRL. Omrabia should be included in the breeding programme as a parent so that while maintaining high GY, resulting progeny should be better able to resist drought through DRL.

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P 6.48 - Developing and testing of near-isogenic lines for drought resistance in rice(Oryza sativa L.) Senthil A.1, Sheeba J.A.1, Amudha K.1, Prince K.S.J.1, Suji K.K.1, Biji K.R.1, Gomez S.M.2, Kanagaraj P.1, Senthilvel S.3, Nguyen H.T.4, Babu R.C.1 (chandrarc2000@yahoo.com) 1 Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology, Tamil

Nadu Agricultural University, Coimbatore, India; 2 Texas Agri Life Research, Texas A & M University System, Lubbock, TX 79403, USA; 3 Agricultural Research Station, Paramakudi, India; 4 Division of Agronomy, University of Missouri - Columbia, Missouri 65211, USA. Selection for a well-developed root system with long, thick roots should improve the drought tolerance of upland rice because the plant would avoid water stress by absorbing water stored in the deep soil layers. Phenotypic selection for root morphological traits in conventional breeding programmes is unfeasible, which paved the way for development of several mapping populations to detect quantitative trait locus (QTLs) influencing root morphology and other drought-related traits that could then be used in marker-assisted selection (MAS) to improve upland varieties. QTLs linked to drought resistance components and plant production traits under stress were mapped in CT9993-5-10-1-M/IR62266-42-6-2 doubled haploid lines. Chromosome 4 and 9 harboured consistent QTLs for root traits and yield components under drought stress and the favourable alleles were contributed by CT9993-5-10-1-M, an upland japonica ecotype. A deep root system contributes efficiently to maintaining the water status of the crop through a stress period. Once stable QTLs for drought resistance are identified, they should be introduced into a near-isogenic background using MAS strategy to assess their agronomic value and contributions to yield in target environments. Near-isogenic lines (NILs) in IR20 and IR64 genetic backgrounds are developed through marker assisted breeding. Four QTLs on chromosomes 4 and 9 linked to root traits and yield under stress from CT9993 were chosen for introgression and development of NILs. BC4F1 and BC2F1 progenies, respectively in IR20 and IR64 backgrounds carrying the QTLs of interest are developed. Further backcrossing is in progress. The accurate characterization and validation of the introgressed QTLs allow to more accurately determining its applicative value. The potential impact of root trait QTLs on yield under drought was studied by evaluating a subset of IR62266 NILs carrying root trait QTLs from CT9993 were field tested along with parents under rainfed conditions in target ecosystem over seasons. Data on plant production under severe stress of these NILs will be presented and discussed.

P 6.49 - Selection for deep and strong root system to combat drought in Aerobic Rice (Oryza sativa L.) Sharma A.K. (amit78sharma@rediffmail.com), Sengar R.S., Singh I.B. Sardar Vallabhbhai Patel University Agriculture & Technology Meerut-250 110, India. Rice is an important staple food of the world particularly of Asia growing a wide range of geographical and climatic condition. Drought in rice is a real concern and a serious yield limiting factor on much of the world’s 70 million hectares of non irrigated rice. Lack of rainfall and the resultant soil moisture deficit from the basis of drought. This situation likely to be more crucial in the near future. To come over drought stress, plants develop some defensive mechanism such as stomata closure, thick cuticle, leaf rolling, profuse or deep and thick root system. Early maturity is also a way to escape drought stresses being a most diverse crop of the world it might be possible to screening out such genotypes having the desirable features for drought stress along with high yield to meet the demands of the ever increasing population of the world. To, conduct an extensive study is difficult to test a large number of varieties/line field screening by visual scoring would appear to be indirect means of screening for root system development. Hence, in order to select the genotypes exhibiting higher germination under higher seeding depth a filed experiment was conducted A field experiment comprising 15 diverse rice genotypes collected from the different places of the country was conducted under Department of Science and Technology Project (GOI) in order to evaluate and screen out the rice genotypes under different seeding depth and drought tolerance in Aerobic conditions. All the fifteen popular high

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yielding rice genotypes/including two hybrids PHB-71 and Pro agro-6444 were sown under four seeding depths viz. surface, 5, 7.5 and 10 cm. The experiment was conducted during kharif, 2006 following RBD design with three replications. All the recommended package and practice were followed to raise a good crop. All the required inputs were applied equally to all the genotypes. The preliminary report of the experiment indicated that all the genotypes showed good germination on surface and 5.0 cm depths But 5 genotypes out of 15 genotypes exhibited good germination at 7.5 cm Depth However only 1 genotypes viz., Jalpriya (variety recommended for flood prone areas) showed about 70% germination at 10 cm seeding depth with good growth which indicated that the genotypes having good germination of 10 cm depth and performed better vegetative and reproductive growth under drought stress. Such flood tolerant genotype also exhibit drought tolerance because due to the roots in subsoils will retain moisture for a relatively longer period.

P 6.50 - Pearl millet pollinator lines bred with a major drought tolerance QTL perform better under salt stress as well Sharma P.C.1(pcsharma.knl@gmail.com), Singh D.1, Sehgal D.2, Khairwal I.S.3, Singh G.1, Yadav R.S.2

1 Central Soil Salinity Research Institute, Karnal, 132001, Haryana, India; 2 Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth, SY23

3EB, UK; 3 All India Coordinated Research Project on Pearl Millet, Mandor 342304, Rajasthan, India. Majority of pearl millet growing areas of the world are characterized by scanty rainfall and saline underground waters. During the times of intense drought, pearl millet farmers are forced to use saline underground waters to irrigate the dying crop. For getting optimum yield under such circumstances, selection for improved tolerance to dual stresses of water and salt is required. Pearl millet lines bred with a terminal drought tolerance (DT) QTL were investigated under different concentrations of salt to assess their responses under salty environments. Six pearl millet pollinator lines bred with a DT QTL, together with the DT QTL donor parental line PRLT 2/89-33 and the drought sensitive recurrent parental line H 77/833-2, were evaluated under saline irrigation water (ECiw 2, 9, 12 dS/m) and alkali (pH 8.5, 9.0 and 9.36) stress. At seedling stage, sensitive parent H 77/833-2 showed maximum decline (90%) in shoot dry weight under salinity (ECiw 12 dS/m), while the tolerant parent PRLT 2/89-33 as well as the QTL bred lines ICMR 1029 and ICMR 1040 showed the least decline (ranging from 44%-48%) compared to their respective controls. Further, under alkali stress (pH 9.36), maximum shoot weight was observed in ICMR 1029. Better performance of these genotypes observed during vegetative stage was also translated into yield and yield component traits. For instance, ICMR 1029 recorded highest plant head yield at pH 9.36 which was higher by 88 and 20% compared to parental lines H 77/833-2 and PRLT 2/89-33, respectively. Similar results were also obtained for plant grain yield. Further, under alkali stress, flowering duration increased on an average by 4 (pH 9.0) to 8 days (pH 9.36) in all genotypes evaluated compared to control plants. Ionic accumulation in different pearl millet lines corroborated with the differences observed in their growth under increased alkali and salt stress conditions. In general, pearl millet DT QTL bred lines retained more Na+ in nodes than in the internodes. The results described will be discussed in the light of plausible salt tolerance mechanisms associated with the DT QTL.

P 6.51 - Improvement of grain legumes through induced mutagenesis for rainfed agro-ecosystem of India Singh A.K.1(awnindrakumar@gmail.com), Gupta R.K.1, Singh I.P.2

1 Sher-e-Kashmir University of Agricultural Sciences & Technology of Jammu, Main Campus, Chatha, Jammu-180 009(J&K), India;

2 Indian Institute of Pulses Research (ICAR), Kalyanpur, Kanpur – 208022 (UP), India. Grain legumes are the popular food and sometimes become the only available source of nutrition and survival for the poor section of population during drought and famine in Asian and African countries. They are indispensible for sustainable cropping systems because of their distinctive characteristics like short duration and ability to fix atmospheric nitrogen and thrive well under adverse conditions. The grain legumes serve as important source of

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food, fodder, oil and fiber and are an excellent source of dietary protein, minerals and energy. Their byproducts provide nutritious fodder for livestock. The newly emerging health consciousness among the people is creating a genuine need for adopting nutritionally complete vegetarian’s diets involving legumes as a component. The beneficial aspects of pulses in sustainable rainfed agriculture have long been known and extensively documented. Grain legumes are next only to cereals in terms of agricultural importance and have been considered the best options for diversification and intensification of rainfed agriculture across the globe because of their intrinsic values such as nitrogen fixing ability, higher protein content and ability to thrive well in the less endowed environments. Genetic variation among existing cultivars and in germplasm of the grain legumes is the outcome of selection during evolution and plant breeding. Mutation is any heritable alteration in genetic material includes such diverse phenomena as change in the number of chromosomes, changes in the structure of chromosomes and changes within the genes themselves. Mutagenesis offers to the plant breeders, a chance to tackle unconventional objectives, particularly those that were at a selection disadvantage in the past. Effective mutagens are available, but the bottleneck is the effective selection of rare desired variants from large mutagenized populations. In grain legume, mutation breeding has already led to improved cultivars with higher yield, better grain quality, or stronger resistance to pathogens. Many mutations affecting nitrogen fixation related traits have also been reported. Induced mutations can be beneficially utilized for tailoring better varieties of crop plants by plant breeders. Mutation breeding employing gamma radiation was initiated to explore its potential for genetic up gradation as well as to elucidate the feasibility of developing translocation and multiple interchange stock, which has the tremendous value in linkage analysis. Many crop improvement programmes are presently addressing researches on different aspects of pulse improvement programme and mutagenesis can be a valuable supplement to conventional breeding methods.

P 6.52 - Effective use of client-oriented breeding and marker assisted breeding in Asia Steele K.A. (k.a.steele@bangor.ac.uk), Joshi K.D., Virk D.S., Witcombe J.R. CAZS Natural Resources, Bangor University, LL57 2UW, UK. Client-oriented breeding (COB) has been successfully applied in Asia for a range of crop species. To date 9 rice varieties have been released in three countries and over rice 15 varieties have been adopted. COB removes the gap between the research environment in which genotypes are traditionally selected and the target environments in which they are grown. Hence, in our breeding programmes for rice improvement in India, Bangladesh and Nepal, selection is made under the typical drought-prone conditions of the farmers’ fields. Since the resulting varieties can better meet the needs of the client farmers they are more rapidly adopted even by poor farmers in marginal environments. COB can be much more efficient than conventional breeding, with uptake of new varieties occurring as early as 2 years after their initial selection in variety trials compared with conventional breeding and extension methods that usually result in a lag of 7-8 years between variety development and appreciable adoption. Accelerated variety development and adoption thus allows breeders to keep pace with climate change. We have used molecular markers to augment COB in rice and improve the efficiency of selecting for difficult desired traits such as drought tolerance. By combining farmer and marker selection we have been successful in producing adapted varieties that farmers want to continue to cultivate and that scientists can recommend. We carried out a line conversion programme to transfer multiple root QTL and aroma in to an Indian upland rice variety. The process built on previous QTL mapping work and involved more than 3,000 marker assays. The resultant material was tested with 700 farmers on a total of approximately 100 ha. The rice variety Birsa Vikas Dhan 111 (PY 84) is the first released variety to be developed from a combination of MAS and COB. We also applied markers in simple, but novel process, termed marker evaluated selection (MES) and demonstrated that it can reveal markers associated with improved yield under drought. It requires no prior knowledge of QTLs but relies on estimating changes in allele frequency when the principles of client-oriented breeding are followed, i.e., strong selection in the target environment in crosses involving carefully chosen, contrasting parents.

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P 6.53 - SSR marker linked to spikelet fertility under drought stress in rice Suji K.K.1, Joel A.J.2, Babu R.C.1(chandrarc2000@yahoo.com) 1 Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology, Tamil

Nadu Agricultural University, Coimbatore – 641 003, India; 2 Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore – 641 003,

India. Water stress induced spikelet sterility limits rice production under upland conditions. Spikelet fertility under drought stress conditions is not only a highly informative indicator for severity of drought stress, but also the most important determinant of yield under drought stress conditions. To study the relationship between traits (spikelet fertility) and their genetic control and to reduce the number of plants to be genotyped several strategies have been employed. Bulked Segregant Analysis is one such strategy for identifying DNA makers linked to the trait of interest against a randomized genetic background of unlinked loci. Keeping this in view, bulked segregant analysis (BSA) was performed to identify SSR marker linked to spikelet fertility under drought stress, an index of drought tolerance in rice. A F2 population, from a cross between IR20, a lowland cultivar and Paiyur local (PL), a drought tolerant traditional cultivar, was developed and screened for drought response under field conditions. Based on spikelet fertility percent under drought stress, 13 drought tolerant (> 85 percent spikelet fertility) and 13 drought susceptible (< 40 percent spikelet fertility) F2 genotypes were selected. A total of 326 SSR primer pairs representing the rice genome were selected to amplify the SSR regions and 94 primers were found to be polymorphic between the parents. DNA samples from the selected drought tolerant and susceptible genotypes were pooled, respectively in to drought tolerant and susceptible bulks and were screened using the 94 polymorphic SSR primer pairs. The marker, RM 152 was found to be polymorphic between the bulks and also co-segregated in the F2 genotypes constituting the bulks. RM 152 mapped on chromosome 8 of rice was reported to be linked to several drought resistance traits and can be used in marker assisted selection.

P 6.54 - Assessment of pigeonpea genotypes (Cajanus cajan L. (Millsp.) for drought tolerance in central India Tikle A.N.1(antikle@yahoo.co.in), Kandalkar V.S.2, Hussin A.3, Majumder N.D.4, Jamdagni B.M.5

1 College of Agriculture, Sehore, R.V.S. Agricultural University (Gwalior) Madhya Pradesh State, India; 2 Zonal Agricultural Research Station, Khargon R.V.S. Agricultural University (Gwalior) Madhya Pra-

desh State, India; 3 Department of Plant Physiology, University of Agricultural Sciences, Banglore, Karnataka State, India; 4 Project Coordinator (Pigeonpea), Indian Institute of Pulses Research, Kanpur, Uttar Pradesh State, India; 5 Mahatma Phule Agricultural University, Rahuri, Maharashtra State, India. Pigeonpea (Cajanus cajan L. (Millsp.) is a major rainy season pulse crop of India. It accounts about 77% of world acreage (FAOSTATSTICS 2008). The major protein source of Indian vegetarian diet are pulses and pigeonpea is used in daily lunch of every Indian as source of protein, especially in central India. In general, this crop is grown in marginal and sub-marginal soils under rainfed condition. As forecasted by environmental scientists and world's meteorologists, rains will be limiting in next 10 years. The pigeonpea crop suffers at lateral stage of pod filling due to moisture stress as winter rains are scarce in central part of India which is a major pigeonpea growing falls. Genotype JSA 59 ranked first giving an yield of 1563 + 106 kg/ha in rainout shelter and 3295 + 191 kg/ha in field condition in the year 2005 at Rahuri center. On the basis of five year’s results genotype BSMR 736 ranked first in 2004 and second in 2007 while JSA 59 ranked first in the year 2006 and 3rd in the year 2007 and 2008 for lesser reduction in yield under stress. For high yield under terminal moisture stress genotypes identified were BRG 2, TTB 7, BSMR 736, JSA 59 and PT 25-6 for Banglore (Karnataka State center; JSA 59, PT 25-6, BSMR 736, GT 101, JKE 206, WRG 42 and GTH 1 for S.K.Nagar center (Gujrat State) and PT 25-6 and BRG 2 for Khargone center (Madhya Pradesh State). Concluding the results BRG 2, TTB 7, BSMR 736, GT 104, JSA 59, PT 25-6, WRG 42, JKM 189, JKE 206 are the suitable genotypes for incorporation of resistance against terminal stress in

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high yielding pigeonpea varieties. Root length, root spread, root/shoot ratio, root biomass, moisture retention of leaves, rate of water loss, relative leaf water content, membrane injury index as morphological traits and comparative lesser yield reduction under water limited environment as yield attribute may provide indices for drought tolerance of genotypes. Stability of some of these traits across the locations can provide a tool of selection in identification of suitable genotypes. This paper will try to highlight the identification of genotypes having tolerance to stress condition with minimum loss in seed yield and will also highlight for the selection of traits for future breeding programme of pigeonpea crop and selecting suitable ideotypes for drought tolerance.

P 6.55 - Comparative molecular approaches to identify large effect drought tolerant QTLs in rice Vikram P. (P.Vikram@cgiar.org), Kumar A., Dixit S., Espirtu M., Cruz T.S. International Rice Research Institute, Los Banos, Laguna, Philippines. Drought is the most severe abiotic stress reducing rice grain yield on over 23 Mha rainfed area. Progress in breeding for drought tolerance has been slow. As a result most of the varieties grown in rainfed areas are varieties bred for irrigated situations and are highly susceptible to drought. Development of drought-tolerant varieties could be made more efficient by MAS to introgress alleles of QTL conferring improved drought tolerance into the genome of widely used cultivars through marker assisted backcrossing (MAB). For the traits of low heritability- drought, MAB may be more efficient than phenotypic selection. However, for MAB to be worthwhile, the target QTLs must have a large and consistent effect on yield. Several experiments have reported QTLs for yield and yield components under drought. However, most of these QTLs show high genotype x environment and QTLs X genetic background interactions. Identification of QTLs with consistent effect in the background of popular mega varieties will provide an opportunity to improve the grain yield of high yielding but drought susceptible mega varieties through introgression of the identified regions. Nagina-22 (N 22), a selection from landrace Rajbhog in Nepal is a known drought tolerant traditional genotype. Three F3:4 RIL populations crossing N22 with three mega varieties IR64, MTU1010 and Swarna were developed to identify QTLs showing consistent effect against these three backgrounds. These populations were phenotyped for reproductive stage lowland drought in DS 2009. Polymorphism survey with 800 SSR markers revealed around 40% polymorphic markers. For N22/MTU1010 population, 130 markers equally spread throughout the genome have been selected for genotyping. Consistent effect of the regions controlling grain yield under drought in N22/MTU1010 population will be verified in the other two populations. Also, efficiency of bulk segregant analysis (BSA) and selective genotyping in identifying major QTLs for grain yield under drought as compared to whole population approach will be ascertained. Preliminary data indicates allele shifts towards N22 on chromosome 1 and 8.

P 6.56 - A priority breeding strategy approaching drought tolerant rice Wang H.Q.1 (wanghuaqi@cau.edu.cn), Kang D.M.1, Zhao D.L.2 1 China Agricultural University(CAU); 2 International Rice Research Institute (IRRI); To save water resource and sustain rice production in the world, developing drought tolerant rice is urgent and a strategical challenge. Unfortunately most of cultivars in rice are susceptible to drought. Using the biotechnology of exogenous gene transfer in rice breeding program for drought tolerance improvement is still difficulty, long way, and especially rare of successful case studies. The practice, experience and advance in drought tolerant rice breeding in China recent three decades showed that selecting drought tolerant variety from the existent lowland rice germplasm or derived its intermediate generations is very low probability and limited progress and that pedigree selection relying on nature mutation in drought tolerant rice is too slow to meet the demand for varies farmers. The successful case studies in China indicated that the most effective approach is the mode “L×U” i.e. improved lowland rice crossing with conventional upland rice cultivars. There is the possibility combined high yield potential in lowland rice with strong drought tolerance in conventional upland rice. Furthermore, the both the drought tolerance and yield potential are able to be over increased than the either parents by “L×U” breeding program. The mode “L×U” can be recognized as an available and priority technical strategy in drought tolerant rice breeding in the near future.

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P 6.57 - Genetic diversification of pearl millet landraces to combine drought adaptation with high yield in arid zone Yadav O.P. (opyadav21@yahoo.com)

Central Arid Zone Research Institute, Jodhpur 342 003 India. Pearl millet [Pennisetum glaucum (L.) R. Br.] is primary multi-purpose cereal crop in the arid zone of the north-western India meeting the need of food, feed and fodder. This region is one of the most marginal environments for arable agriculture in the world. Droughts of unpredictable intensity, duration and timing are the major production constraint of pearl millet in north western India. Hence drought-resilient traditional pearl millet landraces are commonly grown by farmers principally as a strategy to minimize the risk of crop failure. However, this strategy is at the cost of harvestable yields in more favourable years as landraces often fail to capitalize on the additional resources. Hence there exists a clear need to enhance pearl millet productivity but without sacrificing the critical adaptation to drought stress. Our breeding approach is based on genetic diversification of traditional landraces using elite exotic material to combine adaptation to arid zone environments from landraces with a higher grain yield potential from elite materials. A total of 44 crosses produced from 11 landraces and 12 elite populations have been evaluated under rainfed conditions of arid zone. The magnitude of heterosis for grain and stover yields in crosses between selected Indian landraces and African elite populations was measured as percent increase/decrease in cross performance over its landrace parent. Crosses showed an enhanced adaptation range beyond that of their parents. Mean heterosis in our studies was 12%-15% for grain and stover yields with individual crosses expressing up to 40% improvement over landrace parent. The expression of grain yield heterosis in best crosses was realized through differential expression of heterosis in various yield-contributing traits. Positive heterosis for biomass resulted into positive heterosis for both grain yield and stover yield. On the other hand, contradictory contribution of heterosis for harvest index on grain yield and stover yield heterosis was observed. Generally, only those crosses that had a combination of high heterosis for biomass with no negative heterosis for harvest index resulted into positive heterosis for grain and stover yields. Thus exploiting heterosis appeared effective and rapid way to amalgamate drought tolerance and high productivity in order to improve both grain yield and stover yield in pearl millet under marginal conditions of arid zone.

P 6.58 - Response of soybean mutant line to drought under in vitro culture Yuliasti (upikyuliasti@yahoo.com) Andhra Pradesh, Indonesia. Drought is one of the limiting factors for better plant performance and higher yield in Indonesia. In vitro screening for stress tolerance will have significance in identifying mutant with optimal stress tolerance and productivity. The objectives of this experiment were to determine response of soybean mutant line against polyethylene glycol (PEG 6000) in vitro condition. In vitro callus cultures of five mutant line and three soybean variety grown showed a reduction in callus growth during PEG 15% treatment as compare with the control. Addition of PEG 6000 15% in the medium elevated dry matter content compare with the control. Cotyledonary nodal explants subjected to 15% PEG treatments resulted in 55% reduction in callus induction G4 mutant line compare with the control. A linear and significant reduction in germination dry weight and dry matter were observe for mutant line as the concentration PEG 15%. Reduction of dry weight of seed germination of G4 mutant line (0.627 g) was stronger compare with the control (1.239 g). Our resulted can be used for in vitro screening.

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P 6.59 - Breeding drought resistance and high water use efficiency crop variety play an important role in global food and water security Zhang Z.B. (zzb@sjziam.ac.cn), Xu P. Center for Agriculture Resources Research, Institute of Genetics and Biological Development, Chinese Academy of Sciences. 286 Huaizhong Road, Shijiazhuang, Hebei 050021, China. There are many problems for food and water security in the world at present, global financial crises lead to less money invest to agriculture and water conservancy project, and as with the global warming, fresh water resource is shorting by less rainfall and much pollution, agriculture-use-water resource faces tough competition with city and population, so ‘more crop for every drip” is the only one way for agriculture, breeding drought resistance and high water use efficiency crop variety play an important role in global food and water security. Beside project-water-saving and agronomic-water-saving should be pay much attention, bio-water-saving should be stressed greatly in some developing and poor countries and regions in the world, because bio-water-saving need less money investment, but it is easily and widely applied in large areas, and has longer effect for water-saving and increase yield in arid and semiarid land. Meanwhile, we should pay more attention for enhancing crop water use efficiency and genetic high yield potential in some countries and regions with much water resources, for example in China, there are more food transfer from north to south at present, but there are more water resource in south than that of in north, so China government should change this situation, and encourage the farmer and agricultural industry plant high yield potential and high water use efficiency crop in south. In some developing countries and poor areas, because there is lack of higher yield crop variety, although there are much water resources, but crop yield is much lower, so breeding and introducing high yield and high water use efficiency crop is the key ways for food security. We should combing drought resistance genes with high water use efficiency genes and high yield genes by bio-technology in crop. We think that more study should be focuses on genetic improving crop water use efficiency for high yielding than drought tolerance, because there is urgent and great need for food from crop under limited water condition in the world.

P 6.60 - The use of an infrared thermometer to detect drought resistance of green couch grass (Cynodon sp.) genotypes collected from the world’s driest inhabited continent Zhou Y.1(yi.zhou@uqconnect.edu.au), Fukai S.1, Cao N.1, Ye C.R.1, Le T.1, Loch D.2, Godwin I.1, O’Brien C.1, Dunne R.1, Giles H.1, Wilson M.1, Halliday M.1, Lambrides C.1 1 The University of Queensland, School of Land Crop and Food Sciences, St Lucia, Australia; 2 Queensland Department of Primary Industries and Fisheries, Queensland, Australia. Increasing demand for scarce water resources in Australia has led to the selection of turfgrass genotypes with good drought resistance and the development of selection techniques. Generally plants grown in dry conditions close their stomata, reducing transpiration and increasing leaf temperature (Tleaf). We measured Tleaf of 52 genotypes of green couch (Bermuda) grass (Cynodon sp.) including 4 commercial varieties and 48 wild ecotypes collected across Australia in two experiments. In the first experiment, all genotypes were grown in polyvinyl chloride (PVC) tubes (40cm long × 10cm diameter) with three replications and clipping to 2cm weekly. Water was not provided after the time the entire canopy had been established in each pot. Survival period, green cover estimated through digital image analysis (DIA) and leaf relative water content (RWC) were used to classify 52 genotypes into drought resistance groups through cluster analysis. The high drought-resistant group (HDR) had lower daily evapotranspiration (ET) in the early stage of drought possibly resulting from lower stomatal conductance (higher Tleaf), and had higher daily ET (lower Tleaf) in the late stage of drought possibly resulting from more available soil water to maintain transpiration. Tleaf was negatively correlated to ET during the whole drought period, but poorly in the early stage (r = -0.47 to -0.56 p< 0.01) and highly in the late stage (r = -0.78 to -0.90 p<0.01). Tleaf was also negatively correlated to RWC and green cover in the late stage of dry-down, but not significantly in the early stage. In the pot experiment the differences between drought resistant groups for clipping dry matter and root dry matter (RDM) were not significant, but significant between genotypes. Genotypes (eight in all) that ranked in the high,

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moderate or low drought-resistant groups from the first experiment were planted in the field. Genotype 81-1 belonging to HDR and having largest RDM in the first experiment maintained lower Tleaf and presumably higher ET than the other 7 genotypes, possibly due to its large root system which could extract more water deep in the soil profile. In summary, in the pot experiment, Tleaf could indicate ET during dry conditions, and RWC and green cover in the late stage of drought. In the field, Tleaf was associated with RDM; however the best performing genotype in the pot experiment had medium RDM. More field experiments are in progress to evaluate this screening methodology for turfgrass research.

P 7.01 - Selection of wheat and rice genotypes for high agronomic water use efficiency in water scarce and salinity environments using the carbon isotope discrimination Adu-Gyamfi J.J.1 (j.adu-gyamfi@iaea.org), Kenzhebayeva S.2, Ram T.3, Nguyen M.L.4 1 FAO/IAEA Agricultural and Biotechnology Laboratory, International Atomic Energy Agency, Wagra-

mer Strasse 5, A-1400, Vienna, Austria; 2 Institute of Plant Physiology, Genetics and Bioengineering, Ulitsa Timiryazeva 45 480090 Almaty,

Kazakhstan; 3 Agricultural Research and Extension Unit, St Jean road, Quatre-Bornes, Mauritius; 4 Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic

Energy Agency, Wagramer Strasse 5, A-1400, Vienna, Austria. Plants discriminate against the heavy isotope of carbon (13C) during photosynthesis and hence the isotopic ratio of 13 C to 12C (Δ) in plant tissues is used as surrogate of water use efficiency (WUE), a function of plant stomatal openings. The technique commonly referred to as the carbon isotope discrimination (CID) is increasingly being used evaluates C3 plants with increased WUE in water scarce and saline environments. Although the relationship between CID and water and /or salt stress is well documented, few studies have examined the interactive effects of salinity and water on Δ. A two-year greenhouse experiment was conducted to assess the potential CID to evaluate and select wheat and rice varieties in combined soil salinity and water scarce environments. Four wheat varieties from Kazakhstan and two upland rice varieties from Sierra Leone were used. Six treatments including (i) control (water applied at field capacity throughout the experiment without salt treatment, (ii) drought 1 (D1, water applied at 30% FC at day 8 after thinning) (iii) drought 2 (D2, water applied at 30% FC at 50% booting) (iv) salt (S, 50mM or 10 dSm-1 applied 8 and 10 days after thinning in 2 splits) (v) drought 1 x salt interaction (D1 x S) and (vi) drought 2 x salt (D2 x S water stress and salt applied at 50% booting for wheat but at 60 days after sowing for rice and maize). For wheat, the D1 and the D1 x salt treatments resulted in a more drastic reduction in DM of spikes than all the other treatments suggesting that the pre-anthesis water stress contributed more to a reduction in DM than the salt stress treatment. The combined effect of water and salt stress resulted in low Δ values compared to the control (well-watered and no salt treatment). High DM was associated with high Δ suggesting that Δ provides an integrated measure of crop water productivity under water limiting conditions, however this relationship was greatly affected under the studied condition of combined salt and water stress environments for rice. The results suggest that selecting crop plants for their greater agronomic efficiency in a combined salt and water stress environments is complex and require further investigations in the field for different crops and soil nutrient conditions. The impacts of nitrogen and phosphorus fertiliser inputs on Δ in this study will also be presented.

P 7.02 - Dew is a major factor affecting the vegetation water use efficiency rather than a source of water in the eastern Mediterranean Ben-Asher J.1 (benasher@bgumail.bgu.ac.il), Alpert P.2 1 Jacob Blaustein Institute for Desert Research Ben Gurion University of the Negev, Israel; 2 Department of Geophysics and Planetary Sciences, Tel Aviv University, Israel. Modern scientists describe the dew mainly as a source of inspiration for poets rather than a source of water to plant since its amounts are negligible but sufficient to promote the spread of plant diseases. This, in contrast to ancients belief that dew is a great source of blessing.

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The purpose here is to re-examine the ecological importance of dew in arid and semi arid regions with a focus over the eastern Mediterranean. This re-evaluation was possible due to the use of PTM (Photosynthesis Transpiration Monitor) that is uniquely capable of continuous measurements of photosynthesis and transpiration. This concept is of particular importance under the prediction that global warming and its associated changes may combine to give some reductions in relative humidity that may be followed by a significant reduce in dew formation. Adana, Turkey was selected as an appropriate semi arid test ground with well documented meteorological data. We demonstrated here that dew formation provides humid environment that minimize transpiration when a significant morning gain from the night respiration that is induced high CO2 gradient. This results in an intensive carbon intake at a low water cost. . In particular it led to average water use efficiency (WUE) of 24.6 gr. CO2 per kg. water compare to 6.6 gr. CO2 per kg. water for unaffected plants. Thus the synergistic contribution of dew to WUE is clearly demonstrated and explains the ecological importance of dew. Moreover, preliminary estimations based on global warming output suggest reductions in the dew frequencies with a potential significant effect on the WUE; a fact not considered yet in the vast literature on global warming impacts.

P 7.03 - Under-utilized species of the genus corchorus in ethiopia: potential edible plant for dryland regions Benor S.1,2 (benor@ipk-gatersleben.de), Blattner F.R.1, Demissew S.2, Hammer K.3 1 Leibniz Institute of Plant Genetics and Crop Research (IPK), Corrensstraße 3, D-06466 Gatersleben,

Germany; 2 Department of Biology, Science Faculty, Addis Ababa University, P.O.Box, 1176 Addis Ababa,

Ethiopia; 3 Department of Agrobiodiversity, Institute of Crop Science, Kassel University, D-34109 Kassel, Germany. Today, most of the people in the world are fed by about few and widely common cultivated crops which are the main safeguard between mankind and starvation. However, reliance on A small number of food crops carries great risk, for monocultures are extremely vulnerable to catastrophic failure brought about biotic and abiotic factors. To help the rapidly increasing world population and combat food shortage in dry regions, it is timely to consider neglected or little-known plant species. Among many of the world’s wild plant resources, the genus Corchorus consists of important species classified as neglected and under-utilized vegetable crops. Ethiopia is recurrently affected by drought and efforts made to tackle food deficit via breeding dryland crops is still inadequate. Corchorus species are known to be drought tolerant and could be used as a supplement to the staple starchy-grain foods in dry areas. These species are also very good sources of proteins, fibres, vitamins and mineral nutrients. However, there is little information on the potential use of these leafy vegetables in the country. Ecogeographical and ethnobotanical studies on Corchorus were therefore conducted in dry areas of Ethiopia to investigate species ecological distribution, adaptation and their use in combating recurrent food deficit in dry seasons. The present study summarizes the potential use of Corchorus species as model and drought tolerant crop for dry regions and emphasizes on creating public awareness about these species as a cheap source of leafy vegetable which can diversify food sources, reduce malnutrition, and contribute to household income generation of the farming community.

P 7.04 - Identification and evaluation on the drought resistance of agronomic traits in new hybrid rice combinations Cheng J.F. (chjfkarl@163.com) College of agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China. Thirty new hybrid rice combinations were selected as experiment material and were planted in the dry land and wet land in this experiment. The agronomic traits (Tillering number, seedling height, plant height, panicle length, primary branches, secondary branches, panicle internode width, grain density and grain yield per plant) in new hybrid rice combinations were measured, and single and comprehensive identification and evaluation of new hybrid rice combinations were carried with fuzzy subordinate function value of drought response percentage (DRP)

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in the agronomic traits. The results showed that coefficient of variation (C.V.) in the agronomic traits of new hybrid rice combinations were different. C.V. of secondary branches both in the wetland and in the dryland were maximum and plant height in the wetland and panicle internode width in dryland were minimum. C.V. of the panicle internode width in the wetland was larger than that in the dry land, but C.V. of the others in the dry land were larger than those in the wetland. DRP of the agronomic traits in different new hybrid rice combinations were rather different; regarded them as the criterion of classification and evaluation, the results showed that types of drought resiatance in different new hybrid rice combinations were related with the agronomic traits. According to tillering number, panicle length and grain density, middle drought resistances of hybrid rice combinations were most, while the high and the low were few; according to primary branches, secondary branches, panicle internode width, and grain yield per plan, low drought resistances of hybrid rice combinations were most, while the middle and the high were few, especially when according to panicle internode width, middle drought resistance of hybrid rice combination was no; According to plant height, high drought resistances of hybrid rice combinations were most, while the low and the middle were few; according to seedling height, middle and low drought resistances of hybrid rice combinations were most, while the high were few. Fuzzy subordinate function value of DRP and comprehensive drought resistance of agronomic traits in different new hybrid rice combinations were different, regarded them as the criterion of classification and evaluation, middle and low drought resistances of hybrid rice combinations were most and the high were few with tillering number and secondary branches; Low, middle and high drought resistances of hybrid rice combinations were slightly same with seedling height; High and middle drought resistances of hybrid rice combinations were most and the low were few with plant height; Low drought resistances of hybrid rice combinations were most, while the high and the middle were few with panicle length, panicle internode width and grain yield per plant; Middle drought resistances of hybrid rice combinations were most, while the highs and the lows were few with primary branches, grain density and comprehensive drought resistance. The correlation and discrimination analyses indicated that markedly significant correlation between the DRP of secondary branches was the highest and discrimination percentage of types which were classified by secondary branches was the highest with 70%. Therefore, secondary branches were the indirect and dependable index as the identification and evaluation on drought resistance of hybrid rice.

P 7.05 - Revealing the yield impacts of organ-level quantitative trait loci associated with drought response in maize - A gene-to-phenotype modelling approach Chenu K.1,2(karine.chenu@dpi.qld.gov.au), Chapman S.C.3, Tardieu F.1, McLean G.2, Welcker C.1, Hammer G.L.4

1 INRA, UMR 759 LEPSE, 2 place Viala, 34060 Montpellier cedex 01, France; 2 APSRU, Primary Industries and Fisheries, Toowoomba, Qld 4350, Australia; 3 CSIRO Plant Industry, St Lucia, Qld 4072, Australia; 4 APSRU, School of Land, Crop and Food Sciences, University of Queensland, Brisbane, Qld 4072, Australia. Substantial genotype-environment (GxE) interactions make crop improvement for drought tolerance a major challenge for plant breeding. Part of the impact of drought on corn yield arises from reduction in leaf expansion that affects light interception and from reduction in silk expansion that affects grain set. Recently, quantitative trait loci (QTL) have been shown to be associated with responses of leaf and silk expansion to soil water status and evaporative demand. As part of understanding and exploiting GxE interactions for yield, we propose a modelling approach to bridge this gene-to-phenotype gap. In this study, we combined (i) a short-term model (hourly) of maize leaf expansion that captures the effects of genetic and environmental variations, with (ii) a new model co-ordinating the development of all leaves of a plant, and (iii) the APSIM crop model which takes account of the complex plant-crop-environment interactions at a daily time scale. The integrated model adequately predicted the profile of leaf area in 12 field situations with contrasting evaporative demand and soil water conditions, and it accurately simulated biomass accumulation and yield in 3 field situations. The model was used to evaluate the influence at the crop level of previously identified QTL for leaf and silk elongation. The yield of hypothetical recombinant inbred lines (RIL) was simulated for a range of climatic and drought conditions. QTL for faster leaf elongation increased crop yield under well-watered or pre-flowering deficit conditions, but reduced yield in terminal stress environments, as such ‘leafy’ genotypes prematurely exhausted their water supply. The QTL impact on yield was substantially enhanced by including pleiotropic effects of these QTL on silk elongation and on consequent grain set.

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Simulations with this relatively simple model demonstrated the difficulty of interpreting the genetic control of yield at crop level. The results highlight the potential of functional whole-plant modelling for bridging the gene-to-phenotype gap and for understanding GxE interactions for complex traits such as drought tolerance.

P 7.06 - Response of moisture for several vines Duan B.H.1( dbhbac@sohu.com), Chen F.2, Han B.P.1, Li L.B.1 1 College of Plant Science and Technology，Beijing University of Agriculture,Beijing 102206, China; 2 College of Agronomy and Biotechnology，China Agricultural University，Beijing 100193, China. In recent years, along with exacerbation of global eco-environmental problem, ecological function of vegetation restoration and reconstruction has been one of ecological hotspots regarded by people. Photosynthetic gas exchange parameters has been researched on crop and economic forest centralized mostly. Research on variety rule of photosynthesis physiological index of Lianas was rather little under a series of soil moisture grads. Therefore, using, synthetically the theory of plant water use efficiency, and regarding Euonymus fortunei, Morden cvs.of Chlimbers and Ramblers, Lonicera japonica Thunb, Hedera neaplensis var. Sinensis as experimental materials, Study on vine water response. The results as follow: (1)Under the conditions of soil water stress, four types of vine are basically the same trend. Extent of soil water stress, Slow-growing plants, and even death; with increasing the relative permeability of the plasma membrane; lower chlorophyll content; but different species of soil water stress have significant differences in the response. (2)AB total chlorophyll content from high to low as follows: Hedera neaplensis var. Sinensis> Morden cvs.of Chlimbers and Ramblers> Euonymus fortunei> Lonicera japonica Thunb; Leaf water retention capacity from strong to weak are: Hedera neaplensis var. Sinensis ei >Euonymus fortun> Morden cvs.of Chlimbers and Ramblers> Lonicera japonica Thunb; Plant cell membrane injury rate from low to high as follows: Hedera neaplensis var. Sinensis> Euonymus fortunei> Morden cvs.of Chlimbers and Ramblers> Lonicera japonica Thunb. Come to the conclusion: they sort of drought resistance for the Hedera neaplensis var. Sinensis> Euonymus fortunei> Morden cvs.of Chlimbers and Ramblers> Lonicera japonica Thunb. In order to filter out the Hedera neaplensis var. Sinensis in arid conditions have a stronger endurance, suitable for promotion.

P 7.07 - Improving abiotic stress tolerance in soybean by the introduction of rd29A:AtDREB2A construct Engels C.1,2, Kanamori N.3, Fuganti R.1, Rodrigues F.A.1, Girotto L.1, Leite J.P.1, Rolla A.A.P.1, Marin S.R.R.1, Silveira C.A.1, Farias J.R.B.1, Neves de Oliveira M.C.1, Neumaier N.1, Abdelnoor R.V.1,

Marcelino F.C.1, Yamaguchi-Shinozaki K.3, Nepomuceno A.L.1(nepo@cnpso.embrapa.br)

1 Embrapa Soybean, Caixa Postal 231, CEP 86001-970 Londrina, PR, Brazil; 2 Londrina State University; Londrina, PR, Brazil; 3 JIRCAS (Japan International Research Center for Agriculture Science), Tsukuba, Japan. Drought is the main cause for annual oscillations in soybean production worldwide. Plants respond to water deficit conditions in molecular, physiological and morphological levels. Among the genes involved in water deficit responses, there are Transcription Factors (TF) such as AtDREB2A. AtDREB2A (Dehydration Responsive Element Binding protein) activates others genes linked to cellular defenses against dehydration, heat and saline stresses. One strategy to reduce yield losses is the development of tolerant cultivars. Thus, using biobalistics transformation method, the genetic construction rd29A:AtDREB2A was inserted in soybean embryos, cultivar BR16, aiming to improve drought and heat tolerance. PCR results showed a transformation efficiency of 54%, considering 920 tissue culture regenerated and PCR tested plants. Among 498 PCR positive plants, 341 died after transferring from tissue culture to vermiculite. During the transference from vermiculite to soil pots in the green house, 79 plants died. Seventy eight plants survived dropping transformation efficiency to 8.48%. Two of these positive events, P1397 and P2193, were chosen to be further studied. These plants were submitted to different water deficit stress treatment: leaves from T0 generation were placed in plates and submitted to dehydration at 0

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min (control), 30 min and 90 min, at 30 . After that the AtDREB2A TF gene expression was quantified by real ℃time PCR. Results showed that when events were compares to their control (0 min), event P1397 expressed DREB2A TF 172 and 109 fold at 30 and 90 min of dehydration treatment, respectively. Event P2193 showed 3.7 and 3.8 fold at 30 min and 90 min of water dehydration, respectively. These results demonstrated that the induction of rd29 stress inducible promoter occurred in both events. Additional studies are being conducted to obtain more data to confirm AtDREB2A effects on improving drought tolerance in soybean.

P 7.08 - Improving drought tolerance of sunflower Grieu P.1 (grieu@ensat.fr), Maury P.1, Debaeke P.1, Sarrafi A.2 1 Universite de Toulouse, INPT, UMR AGIR, ENSAT, F-31320 Castanet Tolosan, France; 2 Universite de Toulouse, INPT, SP2, ENSAT, F-31320 Castanet Tolosan, France. Sunflower is a valuable crop in dry conditions already removed on poor soils without irrigation. Sunflower is considered well-adapted to drought, although systematic analyses of the physiological bases of it, and purposeful attempts to breed for greater drought tolerance are still limited. Crop modelers and geneticists have developed a vision of their roles in plant breeding from their own perspective. However, to improve breeding efficiency, interdisciplinary collaboration becomes increasingly important. Opportunities for collaboration between crop modelers, ecophysiologists and geneticists are explored in this paper, to propose powerful tool to resolve genotype x environment interactions concerning sunflower subjected to drought. Several views of the integration of physiological responses will be discussed. The first looks at basic responses and considers how linkages can be strengthened by genotype or management (e.g., early sowing). The second introduces simulation modeling as a way to study genotype x environment interactions. The paper focuses on significant progress to the study of sunflower and to the integration of knowledge to assist plant improvement and crop management.

P 7.09 - Estimation of regional meteorological and hydrological drought characteristics Jahanbakhsh S.1 (s.jahanbakhsh@tabrizu.ac.ir), Hadiani M.2, Azar Z.N.3

1 Tabriz Universiy , Geographic Faculty; 2 Islamic Azad University, Qaemshahr Branch; 3 Islamic Azad University, Qaemshahr Branch. Information on regional drought characteristics provides critical information for adequate water resource management. This study introduces a method to calculate the probability of a specific area to be affected by a drought of a given severity and demonstrates its potential for calculating both meteorological and hydrological drought characteristics. The method is demonstrated using Mazandaran as a case study. The calculation procedure was applied to monthly precipitation and stream flow series separately, which were linearly transformed by the Empirical Orthogonal Functions (EOF) method. West of Mazandaran was divided into 260 grid-cells of 14 £ 17 km, and the monthly mean and the EOF-weight coefficients were interpolated by kriging. The frequency distributions of the first two (streamflow) or three (precipitation) amplitude functions were then derived. By performing simulations, amplitude functions corresponding to 1000 years of data were generated. Based on these simulated functions as well as interpolated mean and weight coefficients, long time series of precipitation and streamflow were simulated for each grid-cell. The probability distribution functions of the area covered by a drought and the drought deficit volumes were then derived and combined to produce drought severity – area – frequency curves. These curves allowed an estimation of the probability of an area of a certain extent to have a drought of a given severity, and thereby return periods could be assigned to historical drought events. A comparison of drought characteristics showed that streamflow droughts are less homogeneous over the region, less frequent and last for longer time periods than precipitation droughts.

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P 7.10 - The physiological response of two maize inbred lines under drought stress Jian M.1, 2, Zheng J.3, Wang J.H.1,2, Wang G.Y.3 (gywang@caas.net.cn) 1 Beijing key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 10093,

China;

2 Key Laboratory of Plant Genomics and Genetic Improvement, Ministry of Agriculture, China Agri- cultural University, Beijing 100093, China;

3 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Drought stress greatly affects plant growth and crop production. In order to survive, plants have adapted to execute a number of cellular and physiological responses during drought stress. In our lab, after screening dozens of maize inbred lines under drought treatment at the seedling stage, we identified drought-tolerant line Han21 and drought-sensitive line Ye478. In this study, the difference of the physiological responses between the two lines Han21 and Ye478 under drought stress at the seedling stage was investigated. The results of the relative water content (RWC) of the seedling leaves showed that the RWC of both inbred lines declined under drought stress, but the RWC of Han21 was always higher than that of Ye478 under drought stress. Relative electrical conductivity (REC) measurements indicated that the seedlings of Han21 showed lower REC under drought stress than Ye478. The results of trypan blue staining showed that spontaneous cell death was observed after moderate drought stress in Ye478, but not in Han21. Under severe drought stress, Han21 accumulated more proline and trehalose than Ye478, and the proline and trehalose content of Han21 decreased more quickly after re-watering than Ye478. Taken together, the lower degree of cell death and lower REC in Han21 indicated the better protection mechanism of cell membrane in Han21 than Ye478. And the more contents of proline and trehalose in Han21 may contribute to the better drought tolerance of Han21. Another purpose of this study is to establish the evaluation system for maize seedling under drought stress, and the results can be applied to QTL mapping of drought tolerance in maize.

P 7.11 - Agriculture and sustainable livelihood in drought prone areas using participatory geographical information systems (pGIS) Kumar A. (amiitk@gmail.com) Centre for the Study of Regional Development, Jawaharlal Nehru University, New Delhi, India. The sustainability of human-environment relationship depends upon resources use patterns. In order to study the perpetual drought conditions and growing demands of resources, the various aspects of agricultural practices, water use techniques and institutional settings to be taken into account. This study is an attempt to study the agricultural practices and change in resource availability. The traditional practices the societies of these regions have maintain the social and ecological resilience since early of civilization. The purpose of the study is to find out sustainability aspects of agriculture and related livelihood in these environments using participatory Geographical Information Systems (pGIS). Participatory GIS requires a combination of software tools for group decision support, individual decision support and geographic analysis and presentation. It can provide a better solution of many governance related issues of ownership, distribution, resource allocation and site determination. Participation of local community at different data inputs in GIS enables to produce a holistic and efficient output. It provides a new approach to manage the agricultural practice in drought conditions. It can monitor the impacts of policies and management plans on the natural resource base and livelihood strategies. In this way pGIS straightens democracy and also increases empowerment. Present paper has demonstrated the usability of participatory Geographical Information Systems (pGIS) in drought prone areas of Maharashtra state of India.

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P 7.12 - Effects of film mulching on soil ecological properties and pineapple plant growth in autumn and winter arid phase in Guangdong Liu C.H.1 (founderlch@126.com), Liu Y.1, Yi G.J.1, Tang X.L.1, Liao M.J.2

1 Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; 2 Centre of Agricultural Technology Extension of Zengcheng City, Guangzhou 511300, China. Pineapple is one of the important fruit trees in south China’s Guangdong province. But the pineapple growth is usually suffered from the arid condition and less rainfall in autumn and winter. Film mulching is a useful method to maintain the temperature and humidity condition in soil which has been reported in a few papers. In this trial, the pineapple cultivar ‘Australia Cayenne’ was used as material to study the effects of black film mulching on vegetative growth and soil ecological properties, and no mulching cultivation (open field) was treated as control. The results showed that film mulching improved the soil ecological condition where the pineapple planted and promoted the growth of pineapple. Film mulching slowed down the soil temperature’s rapid rising, decreased the highest temperature at noon, and increased the content of water in soil. Film mulching decreased the content of available nitrogen, phosphorus and potassium in soil in some degree, but increased the content of organic matter. Film mulching increased the number micro-organism in soil such as bacteria, fungi and actinomycetes. Film mulching increased the enzyme activity of soil such as urease, acid phosphatase, catalase in autumn and winter, but decreased the activity of prolease. Also, compared with control, film mulching promoted the plant growth of pineapple. The plant height, number of leaves and roots, fresh weight of plant above ground, fresh weight of roots, and activity of root were increased.

P 7.13 - Real-time spatial analysis of root water uptake in rhizotrons Lobet G.1 (guillaume.lobet@uclouvain.be), Javaux M.2, Pagès L.3, Draye X.1 1 Crop Physiology and Plant Breeding, Université catholique de Louvain, Croix du Sud 2-11, 1348

Louvain-la-Neuve, Belgium; 2 Dep. of Environmental Sciences and Land Use Planning, Université catholique de Louvain, Croix du

Sud 2-2, 1348 Louvain-la-Neuve, Belgium; 3 Plantes et systèmes horticoles, INRA, Domaine Saint Paul - Site Agroparc - 84914 Avignon Cedex 9,

France. Nowadays, drought is a major constraint on crop production and becomes increasingly prevalent. The availability of water for plants defines constraints for stomatal conductance (which affects photosynthesis and yield) and is critical at several sensitive phenological stages, such as flowering and grain filling (some may have irreversible effects). It is therefore important to improve the capacity of plants to use and uptake water in various environmental conditions. The availability of water is defined by (i) soil exploration (root architecture), (ii) conductivity of individual root segments and (iii) quantity and capacity of bulk-to-rhizosphere water flow. These factors must be considered simultaneously if we aim at tailoring root architecture to improve water stress tolerance. We propose a combination of tools based on thin 2D rhizotrons that allows both root architecture and soil water content to be monitored. This experimental platform is combined with two models. One generates a 3D root system with hydraulic conductivities of individual roots as a function of age, type… The second model (R-SWMS) simulates root water uptake and soil water transfer, based on 3D root and soil hydraulic propertie. This platform is used to study how various aspects of root systems dynamics (such as regulation by aquaporins or ABA, root architecture) interfere with root water uptake using a quantitative approach.

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P 7.14 - Plant design features that improve grain yield of sorghum under terminal drought stress Oosterom V. E. 1(erik.van.oosterom@uq.edu.au), Borrell A.2, Deifel K.1, Broad I.3, Hammer G.1

1 The University of Queensland, School of Land, Crop and Food Sciences, Qld 4072, Australia; 2

Queensland Primary Industries & Fisheries, DEEDI, Hermitage Research Station, Warwick Qld 4370 Australia;

3 Queensland Primary Industries & Fisheries, 203 Tor Street, Toowoomba, Qld 4370, Australia. The crop physiological basis of adaptation to post-anthesis drought stress of stay-green sorghum is not yet fully understood, but restricting pre-anthesis water use has been identified as an important mechanism. Plants with the stay-green trait exhibit greener leaves and stems during post-anthesis water deficit, compared with their senescent counterparts. The aim of this paper is to identify some of the crop physiological processes associated with drought adaptation of four sorghum hybrids that represented the B35 (A35 parent inbred line) and KS19 (RQL12 parent inbred line) sources of stay-green. The hybrids were grown as individual plants in five semi-controlled experiments under well-watered conditions (anthesis harvest) and post-anthesis drought (maturity harvest) and in two irrigated field experiments at two plant densities, all in south-east Queensland, Australia. Observations included leaf area dynamics, transpiration, transpiration efficiency (TE), leaf nitrogen (N), biomass, and grain yield. Under low plant density, both sources of stay-green restricted pre-anthesis plant size. RQL12 hybrids achieved this through early anthesis and a slight reduction in tillering. A35 hybrids had a high leaf appearance rate, which resulted in high early vigour of the main shoot and low tillering. As hybrids did not differ in TE, the smaller plant size reduced pre-anthesis water use. This minimized reductions in grain number under drought, and hence reductions in grain yield. Stay-green hybrids had a high leaf N content per unit leaf area, but this had no impact on leaf senescence under drought stress, which was predominantly driven by water availability. The B35 mechanism of drought adaptation appeared to have little advantage in environments where genotypic differences in tillering were poorly expressed, in particular if this was due to high temperatures early in the season. The drought escape mechanism of RQL12 hybrids through earliness, by contrast, was less dependent on environmental conditions. Plant breeders need to take these contrasting environmental responses into consideration when selecting stay-green QTLs for germplasm that is targeted for specific stress environments.

P 7.15 - Model assisted phenotyping of processes involved in rice response to drought: case study of a tropical japonica population during vegetative phase Rebolledo M.C. (maria-camila.rebolledo@cirad.fr), Forest M., Seranuch C., Soulié J.C., Rouan L., Dinkguhn M., Fabre D., Luquet D. CIRAD French Agricultural Research Center for International Development, Biological Systems: Agro-ecological Adaptation and Varietal Innovation. Montpellier, France. Tropical japonica rice is frequently exposed to drought in upland ecosystems. Its drought tolerance is poor compared to other crops but the group has great genetic, in part unexploited diversity in adaptations. Exploring the japonica’s phenotypic and genetic diversity for drought tolerance is thus crucial to breed rice for drought prone environments. Under such conditions, yield depends on drought timing and intensity along plant phenology. During the vegetative phase, drought affects vigour (leaf number and area, tillering, roots) and therefore resource acquisition. Plant adaptation to drought is a complex mix of physiological tolerance, phenology and morphology, all of which interact with each other and with environment, resulting in phenotypic plasticity. This involves variable regulation of source-sink relationships during morphogenesis (phyllochron, organ expansion, tillering), leaf senescence and transpiration. Studying this system requires dissection into simpler traits involving a smaller number of genes/alleles. However, trait dissection must also account for Genotype*Environment (GxE) interactions and trait plasticity. This is particularly difficult for process based traits that cannot be measured directly. In this context, modelling is relevant if used to dissect a complex system into elemental processes. Each process can be formalized as a response function, with parameters seen as being analogous to genes.

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The objective of this work is to explore the added value of using dynamic whole plant modelling to assist phenotyping plant response to drought, as a basis for a genetic association study. This work focuses on rice plant transpiration and morphogenesis processes evaluated on seedlings of a diverse sample of tropical japonicas. A greenhouse pot experiment was conducted at Cirad, Montpellier, on 203 japonica accessions with three replications and two treatments (irrigated and drought). Drought was imposed by dry-down from leaf-6 appearance until a targeted stress level was reached, as indicated by Fraction of Transpirable Soil Water (FTSW). FTSW and plant transpiration rates were monitored gravimetrically. At the same time a minimum set of morphological plant descriptors and climate were collected, in order to calibrate, for each genotype and in both well watered and stressed conditions, the corresponding modules of EcoMeristem plant growth model . This paper presents first results and discusses the discriminative power and the added value of model assisted phenotyping for the case of rice drought responses.

P 7.16 - Photovoltaic water pumping system–sustainable water irrigation technique under drought prone area Shehrawat P.S. (psshehrawat@hau.ernet.in), Kumar A., Godara A.K. Department of Agriculture Extension, CCS Haryana Agricultural University, Hisar-125004, India. Photovoltaic Systems based Power Plants have emerged as viable power sources for water pumping and are being increasingly used for meeting electrical energy needs in un-electrified locations. Photovoltaic-based water pumping system is eco-friendly in nature and pollution free technology can be more appropriate to the needs of the developing countries like India than solar/thermal energy conversion. The present study was conducted in, purposively, selected Hisar, Rohtak and Jhajjar districts of Haryana state. A total number of 282 respondents, i.e., 141 beneficiaries and 141 non-beneficiaries were interviewed in the sample for the study. The study revealed that due to adoption of PWPS in the Rabi season the maximum decrease in area was observed in wheat crop, whereas, the area under vegetable and horticulture was increased. The same trend was also observed during the Kharif season as the area under traditional crop namely cotton, rice and bajra were decreased, respectively. However, the area under vegetable, horticulture, sugar cane and jawar was increased. A significant majority of farmers had medium level of technical, general and overall knowledge by the adopted respondents. In case of non-adopted, as high as had low level of technical, general and overall knowledge. Majority of adopted and non-adopted respondents had favorable attitude towards PWPS. The PWPS adopted respondents reported that ‘This technology only works in less than 8 meters water table’, ‘High cost of PWPS’, ‘Lack of extension literature’ and ‘Lack of attention of mass media’ was found to be the most serious extension constraint by the adopted respondents, moreover the similar results were also obtained in case of non adopted respondents. Extension functionaries recommended that 16.25, 8.25, 7.58, 5.00, 4.50, 4.16 and 3.66 percent of area should be covered under vegetable, mushroom, horticulture, floriculture, spices, medicinal plants and fisheries, respectively, by PWPS adopted farmers who were having less than 5 acres land holding, while 12.16, 8.00, 5.50, 4.50, 3.16, 2.25 and 1.82 percent area under vegetable, horticulture, mushroom, floriculture, fisheries, spices and medicinal plants, respectively for 5 to 15 acres land holding and horticulture (9.67%),vegetable (8.16%), mushroom (3.17%), floriculture (2.75%), fisheries (2.25%), spices (2.00%) and medicinal plants (1.33%) for more than 15 acres land holding.

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P 7.17 - Root architecture of two sorghum varieties differ than drought stress tolerance Sine B.1 (bsinefr@yahoo.fr), Dao A.1, Chopart J.L.2, Muller B.1, 3

1 Training and Research Regional Center for Food Security and Dry Environments (CERAAS), BP 3320,

Thiès, Senegal; 2 Annual Cropping Systems Research Unit, CIRAD, 7 ch. de l’IRAT, 97410 St-Pierre, Réunion, France; 3 Integrative Crop Modeling Research Unit, CIRAD, avenue Agropolis, 34398 Montpellier CEDEX 5,

France. Root architecture of two sorghum varieties, fitted in Durra race and with different response in drought conditions, has been studied on hydroponic system, pot and in situ on field. These varieties have similar aerial agro-morphological characteristics in optimal growth conditions. In pre-flowering drought stress condition, tolerant variety (SSM1611), has a stable and higher yield than the non-tolerant one (IS16101). On hydroponics conditions and pot growth, varieties are studied at young stage. On field, observations concerned the whole plant cycle. Frequent observations of the aerial system have been made in all the trials, with counting of emerged leaves number and measuring stem height. Adventitious roots number and adventitious roots ranks number have been daily observed on hydroponic system and observations was not destructive. Spatial root disposition on stem was observed on hydroponic condition. On pot and field, these observations were destructive and realised once a week. Adventitious root and their different regions growth (basal none branched region, branched region, apical none branched region) were studied in hydroponic system and in pot. The distribution of the root length density according depth in situ condition was studied using passage model from root impacts to length density. Results show that, the development and the growth of aerial system are practically similar for both of varieties whatever trials conditions. However, for the root system there are some differences in favour of the drought stress tolerant varieties (SSM1611). All the trials showed that, SSM1611 presents a higher adventitious roots number and adventitious roots ranks number than IS16101. Adventitious roots number per rank varies according to the rank and the variety. The distribution of the adventitious roots around the stem seems to be leaded by the same low. Adventitious root of the same rank are balanced distribution around the stem. Until three roots per adventitious root rank, adventitious roots of two successive ranks are distributed in a complementary way around the stem. The growth of adventitious roots and their different regions ((basal none branched region, branched region, apical none branched region)e) present similarity for both of varieties. On hydroponic system, adventitious root length increase first time and then stop their growth to maximal level. However in pot, adventitious root growth seems to bee unlimited. SSM1611 variety reveals a root length density according to depth more important than IS16101 variety one in field. Adventitious roots number, adventitious roots ranks number, and root length density could constitute pertinent and easily accessible drought stress tolerance criterions.

P 7.18 - Enhancing food security through maintenance of crop biodiversity and integrating resource pulses in rainfed areas of India –An overview Singh A.K.1 (awnindrakumar@gmail.com), Singh P.2, Singh V.B.3

Sher-e-Kashmir University of Agricultural Sciences & Technology - Jammu, Chatha, Jammu – 180 009 (J&K), India. The concept of sustainable agriculture involves the evolution of a new type of agriculture rich in technology and information with successful management of available agricultural commodities as well as crop genetic resources, to satisfy the challenging human needs. The crop biodiversity which is a key dimension of any sustainable agriculture strategy provides sustainable production of food, biological support to production and ecosystem services. Management of crop biodiversity through resource pulses, which represent a major component of rainfed agriculture with economic importance have developed and used for millennia to provide food and livelihood security for billions of people. Effective induction of pulses under rainfed agriculture is crucial for obtaining high returns from a production system and is the basis of farming which forms a large part of terrestrial biodiversity, not least in rainfed. Rainfed agro-ecosystem is characterized by limited and variable rainfall that supplies resources in

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pulses. Resource pulsing suggests specific mechanisms by which rainfall variability might contribute to the maintenance of high species diversity in the rainfed regions. The present concept concentrated on various attributes of pulses viz. physiological, morphological and life-history traits that facilitate plant survival and growth in strongly limited variable environments which promote diversity through species differences. The variability among pulses in rainfed agro-ecosystem where maximum pulses are cultivated does not reduce the importance of species interactions in structuring communities. But instead axes of ecological differentiation between species that facilitate their coexistence. Pulses of rainfed also influenced higher tropic levels and entire food webs. Better understanding of low rainfall affects the diversity, species composition and dynamics of rainfed environments can contribute to solving environmental problems streaming from land use and global climatic changes. Pulse crops are poised to play a much greater role in diversifying cropping system in the rainfed areas. Therefore, there is an urgent need for research programme on comparative adaptation among pulse crop remains poorly understands; best management practices and key production risks remain incomplete characterization. Knowledge of rainfall effects of pulse crops in the rainfed areas remains imprecise and inadequate and finally genetic improvement for early maturity, increased yield and improved harvestibilty, biotic and abiotic resistance that can invigorate productivity, so as to ensure that the declining share of food grain crop area gets compensated.

P 7.19 - Screening for improved drought tolerance in the mutant germplasm of leafy amaranth (Amaranthus tricolor) Slabbert M.M.1 (slabbertmm@tut.ac.za), Jansen van Rensburg W.S.2

1 Tshwane University of Technology, P/B X680, Pretoria, 0001, South Africa; 2 Vegetable and Ornamental Plant Institute, ARC-Roodeplaat, Pretoria, 0001 South Africa. Amaranthus is a green leafy vegetable which is considered to be an important source of food and nutrition in resource poor communities. Both the seed and leaves provide a considerable amount of protein, minerals and vitamins to the diet of especially rural people. Although these plants are adapted to rural areas in which they are grown, harsh environmental conditions such as drought have a tremendous impact on quality and yield. In South Africa, where drought is a severe problem, tolerance to drought stress of important food crops such as African leafy vegetables is of great value. The development of tolerant genotypes of neglected vegetable crops that could contribute to food production in rural areas is bound to become increasingly important. Mutation techniques offer several choices, alone or in combination with in vitro and field techniques, for enhancing the improvement of specific characteristics in crop plants. During this study the use of tissue culture techniques, physiological screening methods and field trials in combination with induced mutations was investigated as part of a breeding program to develop leafy Amaranthus genotypes with improved drought tolerance). A. tricolor was selected for further development through mutation breeding technology, and physical mutagens were used. After the dosimetry determination, 48 000 dormant seeds of the parent variety were irradiated at 160Gy. Screening for early drought tolerance involved the screening of seedlings, where M2, M3 and M4 progenies were systematically planted and screened in wooden boxes over a period of three years. The eight M5 progenies selected for improved drought tolerance were screened for relative water content (RWC). Both the wooden box technique and RWC allows us to use screening methods that are both relatively cheap and easy to use, but still give reliable answers concerning drought tolerance in amaranth seedlings and mature plants, respectively. On-farm amaranth cultivation was introduced to various urban and rural farmers in South Africa by the Division Crop Sciences, ARC-Roodeplaat. This was necessary since communities are used to harvest wild amaranth from the field, and not cultivating it in gardens. Two farmers have been identified through community participation for commercial propagation. Demonstration units were established on approximately 60 other farms. The eight putative mutant lines were subjected to three years dry land field evaluation, and community acceptance and palatability were tested.

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P 7.20 - Optimal irrigation scheduling using crop growth simulation model for reservoir irrigation systems under water deficit condition Soundharajan B., Sudheer K.P.(bsoundharagan@smail.iitm.a.in)

Department of Civil Engineering, Indian Institute of Technology Madras, Chennai-600 036 India. Optimisation of irrigation water is an important issue in agricultural production for maximising the yield from the limited water availability. The great challenge for the coming decades will be the task of increasing food production with less water, particularly in countries with limited water and land resources. In India, while agricultural water supply is increasingly limited, many reservoir irrigation systems are routinely operated according to meeting full demand condition (maximum supply), and lack appropriate procedures to adjust the water release at different times along the crop growing season and cropping pattern based on water availability. Consequently, crop production as well as irrigated area are reduced. However, imposing certain level of water stress to the crop in such a way that yield reduction is not significant, will increase the area to be irrigated and total crop return from the available limited water. Optimal irrigation scheduling under deficit conditions is highly complex since it depends on the interaction of irrigation system, soil properties, nature and weather condition, growth stage of the crop and effect of water stress on crop yield reduction etc. Recent developments in crop growth simulation models have given the opportunities for simulating the crop growth under the given soil, weather and management conditions in the field. In this research work, a novel approach for deficit irrigation water management is proposed using crop growth simulation model in an optimisation framework for developing optimal irrigation scheduling and cropping pattern. The simulation-optimisation framework is integrated with reservoir simulation for operating a reservoir for irrigation purpose. ORYZA2000, rice (Oryza sativa) growth model is used for simulating the rice crop in a Genetic algorithm (GA) optimisation framework for developing deficit irrigation management plans. The proposed simulation-optimisation model is applied to a real case study of parallel reservoirs irrigation system, to develop weekly optimal irrigation schedules, weekly reservoir releases for the crop season and irrigated area for the combined reservoir system and the results were compared with existing reservoir operating policy (weekly reservoir releases and cropping area) of operating the reservoirs separately. Generally the results are encouraging and the simulation-optimisation framework can be applied for planning level reservoir operation under water deficit problems.

P 7.21 - A high throughput, cost effective, and all-stage DNA extraction protocol for sorghum (Sorghum bicolor) Sweeney P., Adugna A. (asfaw123@rediffmail.com), Snow A. Post-Doctoral Researcher Department of Evolution, Ecology and Organismal Biology The Ohio State University, USA. A new DNA extraction protocol has been optimized for field studies of sorghum. The protocol uses the Whatman FTATM plant saver card and/or cards made of Whatman ordinary filter paper. Both types of cards were tested for extracting DNA from mature wild sorghum plants in the field and from seedlings in the greenhouse. This method was optimized for sampling wild sorghum populations in remote areas of Ethiopia for studies of genetic diversity at microsatellite loci. A solution eluted from a disc of 6mm diameter, punched from a well soaked card, is adequate to run up to 50 PCR amplifications. The resulting DNA was run on a 3% agarose gel stained with ethidium bromide and viewed under UV transilluminator. Both types of cards were equally effective for extracting genomic DNA for PCR-based analyses. Extracting genomic DNA from mature plants in situ is particularly attractive for sampling at sites that are far from the laboratory where samples are analyzed. Moreover, highly skilled personnel are not required to collect DNA samples using this protocol. The Whatman FTATM card is much more expensive than the ordinary Whatman filter paper. Therefore, without compromising efficiency, the lower cost filter paper is recommended for DNA extraction, especially for institutions in developing countries.

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P 7.22 - Management of late rainy season drought by using extra-early soybean genotype ‘MACS 330’ and its agronomic manipulation for high yield Taware S.P. (tawaresoy@yahoo.co.in), Halvankar G.B., Varghese P. All-Agharkar Research Institute, G. G. Agarkar Road, Pune 411004, Maharashtra, India. In India soybean [Glycine max (L.)Merrill] is mostly grown in rainy season (June to October). The cultivars used for sowing are harvested within 85 to 110 days (mid-late to late maturity). Early maturing varieties generally gave lower yields due to short vegetative growth period than mid-late and late varieties. However, when there are water stress conditions in the months of September and October due to early withdrawal of monsoon rains there is severe reduction in yield of mid-late and late varieties due to poor pod filling. Under such conditions early / extra early varieties perform better than mid-late and late varieties. Agronomic manipulation for early / extra early varieties helps to maximize the seed yield. In the present study, an extra early maturing soybean genotype – ‘MACS 330’ with average of 73 days required for days to mature was evaluated for its performance under different fertilizer doses (F1= 20:60:40 NPK/ha & F2= 30:90:60 NPK/ha), plant densities (P1=0.45, P2=0.60, P3=0.75 & P4= 0.90 million plants/ha) and row to row spacing (S1=22.5, S2=30.0 & S3=45.0 cm) and their combinations in split-split plot design in rainy seasons of 2006 & 2007. Pooled analysis indicated maximum seed yield of 2728 kg/ha in F2P4S3 followed by F2P3S3 (2648 kg/ha), F2P4S2 (2566 kg/ha) and F2P4S1 (2468 kg/ha). F2 (2418 kg/ha) showed significantly higher yield over F1 (2107 kg/ha). Seed yield in different plant density levels indicated progressive significant increase at every level (i.e. P4>P3>P2>P1). P4 recorded maximum seed yield of 2485 kg/ha. Row to row spacing, however, showed non-significant differences among 3 spacing distances. But row to row spacing had significant influence on seed yield in its interactions with fertilizer doses and plant densities. Also the three way interaction of 3 agronomic factors was significant for seed yield. Thus extra early genotypes of soybean can be used in management of late rainy season drought (as drought escape mechanism) when combined with manipulation of agronomic factors like fertilizer dose, row to row spacing and plant density.

P 7.23 - Large-scale screening for drought tolerance at vegetative stage as revealed by biomass measured under water-stressed and well-watered environments, compared with other selection criteria Xu Y.B.1(y.xu@cgiar.org), Lu Y.L.1,2, Hao Z.F.1,3, Gao S.B.2, Zhang S.H.3, Li J.S.4, Vivek B.S.5, Magorokosho C.6, Mugo S.7, Makumbi D.7, Taba S.1, Crossa J.1, Araus J.L.1, Crouch J.H.1

1 Genetic Resource Program, International Maize and Wheat Improvement Center (CIMMYT), Km 45, Carretera, Mexico-Veracruz, El Batan, Texcoco, Mexico;

2 Maize Research Institute, Sichuan Agricultural University, Ya’an, Sichuan 625014, China; 3 Institute of Crop Science, Chinese Academy of Agricultural Sciences, National Key Facilities for Crop

Genetic Resources and Improvement, Beijing 100081, China; 4 National Maize Improvement Center of China, China Agricultural University, Beijing 100094, China; 5 CIMMYT Int., C/o ICRISAT, Patancheru-502324, Greater Hyderabad, (A.P.), India; 6 CIMMYT, 12.5 Km peg Mazowe Road, P.O. Box MP163, Mount Pleasant, Harare, Zimbabwe; 7 CIMMYT, PO Box 1041, Village Market-00621, Nairobi, Kenya. A total of 550 lines collected from breeding programs across the world were evaluated under both well-watered and water-stressed environments (each with two replications) during the 2008 dry season at Tlaltizapan (State of Morelos, Mexico). Water stress at vegetative and flowering stages was imposed by stopping irrigation for four weeks at 6-leaf stage and 2 weeks prior to anthesis, respectively. Vegetative stage screening was based on multiple measurements of biomass before and after the drought stress was applied using the normalized difference vegetation index (NDVI) measured with a portable spectroradiometer (GreenSeeker). Other drought tolerance- related selection criteria evaluated include anthesis-silking interval (ASI), leaf senescence, chlorophyll content, root capacitance, final grain yield and drought tolerance index (DTI, final grain yield under stressed condition compared with the well-watered). Under both well-watered and water-stressed conditions, NDVI was significantly

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positively correlated with chlorophyll content and final grain yield, while negatively correlated with leaf senescence. However, there was no significant correlation of NDVI with ASI or root capacitance. The relative NDVI measurements for the water-stressed environment compared to the well-watered environment did not show a significant relationship with any other selection criteria. In addition, none of the selection criteria were significantly correlated with DTI. Selection index was constructed for drought tolerance based on multiple traits. The 45 lines with the best level of drought tolerance produced an average of more than 700 kernels per plot. All the tested lines have been genotyped using two single nucleotide polymorphism chips each containing 1536 markers. Linkage and linkage disequilibrium mapping for drought tolerance has been carried out and are presented by Lu et al and Hao et al (this conference).

P 7.24 - Molecular variation and phenotypic mutation of upland rice exposing to the space environment Yu S.W.1 (ysw@sagc.org.cn), Luo H.C.1,2, Yu X.Q.1, Mei H.W.1, Luo L.J.1,2

1 Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Germsperm Resources Division (Shanghai), National Key Laboratory of Crop Genetic Improvement, Shanghai 201106, China;

2 Huazhong Agricultural University, Wuhan 430070, China. With the development of space technologies and requirements of human space exploration, the spaceflight has been taken more and more attentions in breeding programs of plant. In these studies, we tried to understand the molecular mechanism of mutation induced by cosmic radiation in rice. Huhan 3 and Huhan 7 are two varieties of upland rice developed by Shanghai Agrobiological Gene Center. To investigate the mechanism and the biological influence of spaceflight induced mutations, the seeds of two rice cultivars were sent to the space with two recoverable spaceships (Shenzhou V and Shenzhou VI) respectively. The seeds samples after staying at space about 1 days and 5 days were take back and propagated to 7 and 5 generations (M7 and M5), respectively. Through observation of agronomic traits and morphology, plant height, heading date, seed shape and awn were shown wider segregation. Identification of drought-resistant capability showed the capability of three mutants was distinctly weakened. Additional, the protein and amylose studied also revealed the biological influence in these mutants. And rice quality of a few mutant were also improved. The SSR/ EST-SSR, InDel and AFLP markers were used to detect the genomic mutation. Sequence analysis of the polymorphism fragments indicated that mutation pattern was very complex, including insertion, deletion, conversion, transversion and their combinations. The most of mutation loci occurred at the 3’ or 5’-end of the fragment in the simple sequence repeat fragment. In some mutants, there were multiple mutation loci through SSR analysis. And based on the mutation genes, the RT-PCR analysis showed that the part of mutations affect the corresponding gene expression. Our results showed that the complex space environment can induce mutation in molecular level resulting in the physiological and morphological changes in rice.

P 8.01 - A new method to select the drought resistance azuki bean germplasm Chen X. (cx@jaas.ac.cn), Gu H.P., Zhang H.M. Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China. 120 azuki bean germplasms were selected from different regions of China, to study the selection of drought- resistance and photooxidation -resistance geamplasms. At first, the azuki bean varieties were planted under the water-manpower-controlled environment in the block. After that, excised azuki bean leaves were submerged in the water, in which CO2 was being low (5 μmol/L), O2 was being low (350 μmol/L). The leaves were irradiated overhead with strong sunshine at 30-35 ℃.The grades of the photooxidation were determined according to the declining rates of the leaves color. The correlation confficient between drought-resistance and photooxidation-resistance was calculated, r =0.792**. This results showed that they had a significant positive correlation between the drought-resistance and photooxidation-resistance in azuki bean. So we suggested that, the detecting technique for photooxidation- resistance may be used as a reference method for identification of drought-resistance gramplasms in azuki bean.

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At last, we found many of these varieties were mid-resistance to photooxidation, resistant and non-resistant varieties were a few. Azuki bean germplasms origin from dry area such as Shan Xi and Tian Jin province seemed more resistant to drought and photooxidation condition compare with that of came from any other provinces.

P 8.02 - Adoption of maize varieties and correlated yield response in dryland farming – a case study of rajasthan (India) Gupta V. (vijaya298@gmail.com) Dry land agriculture in India is characterized by low and unstable production dependent on the natural precipitation. Even if the entire irrigation potential of India is developed by 2010 A.D., about 50 percent of the arable land would remain rain fed (Michael, 1990). It accounts for nearly 70 percent (102 million hectare) of the total cultivated area of 143 million hectare. It contributes 42 percent of the total food grain production of the country, which includes most of the coarse grains, 60 percent of rice, 40 percent of wheat, and 75 percent of the pulses, oilseeds and cotton. In India, where 78% of total production of maize (Zea mays L.) is coming from the dry land tract, it ranks fifth in area, fourth in production and third in productivity among cereals. Maize production in the country has gone up from 4.1 million tonnes in 1960-1961 to 12.5 million tonnes in 2001-2002, also the total area under maize cultivation from 4.4 million ha to 6.6 million ha during this period. This spectacular national level growth in production can be attributed to an increase in its yield. The maize yield has increased from 6.27 q/ha to 19.63 q/ha during this period. Still we are far below than the world average yield of 27.80 q/ha. In terms of world acreage, India stands only next to the USA, Brazil, China and Mexico, whereas with regard to production it ranks eleventh. In Rajasthan state of India, maize occupies a significant position and contributes around 9% of the total maize production in the country after Karnataka, Uttar Pradesh, Bihar, Madhaya Pradesh and Andhra Pradesh. In Rajasthan it is mainly grown in Udaipur, Banswara, Chittorgarh, Dungarpur, Sirohi and Bhilwara districts. There are numerous factors responsible for the low maize yield of 10.47 q/ha in Rajasthan much below than the national average of 19.63 q/ha. There is a long way to go for the poorly endowed resource farmers of the dry farming tracts of Rajasthan who have not yet been able to benefit fully from the fruits of new innovations in maize production. This paper attempts to examine the yield differences across the maize varieties and across dry and the irrigated fields and analyses the factors responsible for such differences in the agriculturally less developed and drought prone states like Rajasthan.

P 8.03 - Spectral reflectance of wheat recombinant inbred lines: a computational modelling study Han L.Q.1,2, Hanan J.3, Dreccer M.F.1 (Fernanda.Dreccer@csiro.au)

1 CSIRO Plant Industry, Cooper Laboratory, Warrego Highway, Gatton, QLD 4343, Australia; 2 The University of Queensland, School of Information Technology and Electrical Engineering, Brisbane,

QLD 4072, Australia; 3 The University of Queensland, Centre for Biological Information Technology, Brisbane, QLD 4072,

Australia. To understand how specific genetic characteristics make plants better suited to drought requires following complex traits through different stages of plant development and under different conditions. Spectral reflectance is a non-invasive technology that has a role in identifying and discriminating for traits in a breeding context, by allowing several traits to be surveyed in a single measurement. Using a single genotype, this technology has been used to simultaneously survey canopy cover, N and water status of the crop. In this study, we integrate computational modelling approaches to simulate the complex interactions between wheat crop architecture and the light environment. A model of wheat development was parameterised for six recombinant inbred lines differing in tillering capacity and stem carbohydrate accumulation, incorporating measurements of the spectral reflectance of wheat organs such as internode, sheath, leaf blade, peduncle and spike. The model is interfaced with a quasi-Monte Carlo light model to simulate a remote spectral reflectance measurement taken in the field. Virtual experiments were run to study the effect of field of view versus crop height, effect of sensor height at selected ages, and effect of architectural differences between the recombinant inbred lines. Similarities and differences based on structural

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variation are examined and the implications for the utilisation of spectral reflectance in closely related breeding materials discussed.

P 8.04 - Increase of size and elongation of roots by Salicylic acid Larqué-Saavedra A.1 (larque@cicy.mx), Martín-Mex R.2, Nexticapán-Garcés A.2, Vergara-Yoisura S.1, Gutiérrez-Rendón M.1 1 Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, Calle 43 No. 130.

Chuburná de Hidalgo. 97200. Mérida, Yucatán, México; 2 Laboratorio GeMBio, Centro de Investigación Científica de Yucatán, Calle 43 No. 130. Chuburná de

Hidalgo. 97200. Mérida, Yucatán, México. Root size plays an important role in plants to overcome or reduced the effect of water stress. The activity of Salicylic Acid (SA) in promoting the elongation of root of intact plants was described in this laboratory since 1998. The present investigation has revealed that the promotion of root growth can be achieved in horticultural plants. Experiments were performed with intact seedlings of tomato (Lycopersicon esculentum Mill.) which were sprayed with low concentrations of SA. Plants were treated at 9 and 13 days after the emergence and 7 days after words they were harvested. Concentrations of 1.0, 0.01 and 0.0001 μM were tested in comparison with a water control. The results indicate that 1 μM SA has a significant effect as to increase of root perimeter, root area and the root length was increased by 43% in comparison with that of the control ass. A dosis response curve pattern is presented. This finding can be used to induce deeper and bigger roots to enhance the uptake of water and nutrients when plants are under water stress.

P 8.05 - Methodology of investigations and practice of Si fertilization in the drought regions Matichenkov V.V.1 (vvmatichenkov@rambler.ru), Bocharnikova E.A.2 1 Institute Basic Biological Problems Russian Academy of Sciences, Institutskaja str. 2, Pushchino,

142290 Russian Federation; 2 Institute Physical-Chemical and Biological Problems in Soil Science Russian Academy of Sciences,

Institutskaja str. 2, Pushchino, 142290 Russian Federation. Interest in silicon and its role in the biology of plants has been constantly increasing during the past decades. Results of numerous studies demonstrate the importance of this element in the formation of plant defense against biogenic and abiogenic adverse ambient factors. However, only the total plant content of Si is analyzed. Actually, in soil solutions and plant tissue are permanently presented the mono- and polysilicic acids and organo-silicon compounds, which have a high chemical and biological activity. Methods for determination of the soluble Si in the soil and plant sap were elaborated and tested for various soil and plants. New information about behavior of mono- and polysilicic acids, interaction of soluble forms of Si with other organic and inorganic components was obtained. The methodology for investigation of the role and function of Si in plants under water stress has several specific points. Planetary problem of fresh water deficiency [the most of which is used for irrigation] can, in part, be solved by corrective application of silicon fertilizers, because the ‘activated’ silicon facilitates decrease of irrigation water amount on 30%–50% without diminution of quantitative and qualitative crops characteristics. Natural source of Si is more profitable, compare with using Si-rich industrial by-products, which can initiate secondary chemical pollution. The special technique for testing of Si-rich materials was elaborated and tested. This technique give possibility to determine the most effective and prospective sources of Si rich materials, which can be use as Si fertilizers.

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P 8.06 - Enhancing the livelihoods of dryland farmers through integrated crop production technologies Raman R. (ramanr_ag@rediffmail.com) Department of Agronomy, Faculty of Agriculture, Annamalai University, Annamalai Nagar, 608 002, Tamil Nadu, India. Dryland Agriculture is practiced in most of the arid and semi-arid areas. It is the main stay of 80 million inhabitants of the Semi Arid Tropics. These inhabitants rely on traditionally organized and fragile agricultural system for livelihood. In Worldwide 615 million hectares of land area under rainfed agriculture. Dryland agriculture is always a challengeable one, since crop management depends on monsoon rains in this land. The main problems of these regions are low rainfall and meager availability of irrigation water. A major portion of rainfall is lost in unproductive losses like evaporation, deep drainage and seepage, thereby leaving a very small amount of water for crop use. Dryland regions are home to large number of poor people and they are custodians of globally important environmental resources. Degradation of these lands will have a negative impact on the environment and the agricultural and bio diversity of eco systems. Most of the dry lands are typified by highly fragile natural resource base, the rainfall is low, and soils are often coarse textured sandy and inherently low in fertility, organic matter, water holding capacity and are easily susceptible to wind and water erosion. Challenges to feed and to fulfill the needs of a growing population in a sustainable way require a better and more comprehensive insight into ecologically sound crop production process, especially in fragile environments of resources poor countries. Sustainable integrated crop management strategies are urgently needed for the protection, preservation, reclamation or rehabilitation of dry lands. Selection of suitable agro-technologies, cropping system is of immense value in drylands. This involves the development of integrated crop production technologies system that consider the combined impacts of soil type, local climate, tillage practice, crop rotation, soil management, choice of crops, integrated farming system, fertility cover and catch crops and strategies for managing water, crop residue and weeds. Technologies are available by which we can increase the yield to a greater extent without any additional investment. Advances in agronomic conservation technologies continue to provide the greatest opportunity to achieve sustainability and profitability in dryland agriculture.

P 8.07 - Phenotyping platform at ciat: improving abiotic stress tolerance of crops and forages in the tropics Rane J. (j.rane@cgiar.org), Rao I., Ishitani M., Tohme J. International Centre for Tropical Agriculture (CIAT, Cali, Colombia). Ever increasing demand for food, predicted global climate changes and rising cost of fertilizers are likely to place agro-ecosystems in a more precarious situation in the near future. Less favored environments are expected to be crucial for future agricultural production while favorable environments have to rely on reduced inputs. CIAT and its partners visualize that improved tolerance to abiotic stresses (drought, low soil fertility, soil acidity) in its mandate crops viz., beans, cassava, rice and tropical forages would be the key for eco-efficient agriculture in tropics. While conventional breeding for abiotic stress tolerance is constrained by complexities in tolerance mechanisms and adoption of traits for screening, new hopes are emerging from advances in genomic research. Molecular biology tools are more efficient now than ever before. However, the knowledge about gene-trait association is the major bottle neck. Through phenomics, CIAT aims to enhance its capacity to complement genomic research and conventional breeding. With a generic permit from Colombian government, CIAT has been uniquely positioned to evaluate gene technology in rice and cassava. CIAT has scaled up its phenotyping facilities for evaluation of gene technology to improve water use efficiency in rice in confined field. Gene technology is being evaluated for the first time for improving drought tolerance of upland rice of Latin America at CIAT, Palmira, Colombia. As an alternative genomic strategy, CIAT aims at robust Marker Assisted Selection(MAS)

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approach to improve water use efficiency in beans, cassava, rice and forages through a high throughput phenotyping in controlled environments and at different field sites. The phenotyping platform will feature automated acquisition of data on plant response to managed stress and high throughput analysis of images obtained from sophisticated visible, infrared and x-ray camera with custom made advanced software that can facilitate field phenotyping and trait phenotyping. Phenotyping platform will be used to characterize available unique genetic materials such as CSSL of rice to develop more efficient genetic markers and to identify superior parental lines with enhanced water use efficiency in its mandate crops. This renewed strategy is largely oriented towards delivering genome knowledge from laboratories to field to realize research impact for eco-efficient agriculture.

P 8.08 - Agricultural landuse planning based on terrain characteristics using remote sensing and geographic information system in the lower river benue floodplain, Nigeria Uchua K.A. (kennuchua@yahoo.co.uk) National Centre for Remote Sensing, P.M.B 2136, Jos, Nigeria. In order to meet the increasing demand for food, the farming community needs to have a good knowledge of landuse and land cover of the area. This can be achieved with optimal success using space technology which has the ability to provide rapid, timely, accurate and reliable data within a given time framework. This necessitated a study on agricultural landuse planning on the basis of terrain characteristics including slope, soil, drainage and erosion parameters using satellite remote sensing and GIS technologies in the Lower River Benue Floodplain, Nigeria. The area is located between Latitudes 7o 13’N and 8o00’N, and Longitudes 8o 00’E and 9o 00’E with a total basin area of 7685.28 km2 and a population figure of 947,138 people (NPC, 2006). A combination of digital data, collateral data as well as attribute datasets were integrated and manipulated in a GIS environment using appropriate software packages. This paved the way for the generation of the land use / land cover map, physiographic-soil map, the drainage map, slope map, together with detail morphometric analysis which led to the prioritization of the sub-watersheds from least priority (alluvial plains) to high priority (pediments) ratings. The integration of the results of slope, physiography, landuse as well as morphometric analysis using the FAO/USDA classification schemes led to the genaration of land capability maps, whereas the appraisal of the lands of the various sub-watersheds in terms of their suitability for the cultivation of paddy (rice) crop in turn revealed that the alluvial floodplain and valley fills are highly and moderately suitable for rice cultivation respectively in the Lower River Benue basin. It has become increasingly apparent that computer based GIS and satellite remote sensing data can provide the environment for effective land capability mapping and suitability evaluation for crop production as a stepping stone for sustained landuse planning targeted at addressing issues of agricultural intensification, food security and poverty reduction in Nigeria.

P 8.09 - A lysimetric system to comprehensively assess the root water supply and other yield components in crops Vadez V. (v.vadez@cgiar.org), Kumar P.R., Krishnamurthy L. International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, 502 324, Andhra Pradesh, India. Most studies on roots have used time consuming methods to assess rooting differences, limiting their use in breeding, and providing “static” data that did not reveal their highly dynamic nature. Here we report a novel system where water uptake, rather than root morphology, is measured in a lysimeters, i.e. PVC tubes filled with soil and mimicking a real soil profile. The system allows a precise, in-vivo, and high throughput assessment of the components of the yield architecture (T, TE, HI) and assess their respective contribution on yield under a range of imposed water stresses. Several experiments included the assessment of the groundnut reference collection, part of the sorghum reference collection, and pearl millet materials introgressed with a terminal drought tolerance QTL. Among the salient results we found that transpiration efficiency varied largely in groundnut in that system and was positively associated with pod yield under terminal drought conditions. Groundnut and sorghum germplasm varied a lot in the total amount of water extracted from the soil profile. However, an experiment with fewer groundnut

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genotypes showed that more than the total water extracted, the pattern of water extraction from the soil profile varied among the genotypes and mattered most for pod yield: High water extraction within the 24 days following stress imposition was negatively related to pod yield (r2 = 0.36). By contrast, water extraction between 24 and 56 days after stress imposition, i.e. a period corresponding to pod filling was positively related to a higher pod yield (r2 = 0.33). In sorghum also there were large differences in these kinetics of water extraction, and relations with yield. The importance of the pattern of water extraction was also confirmed in pearl millet lines differing for a terminal drought tolerance QTL, where tolerant and sensitive lines extracted similar amount of water from about 4 weeks after sowing until maturity. However, tolerant lines extracted less water before and during flowering while more water during grain filling than the sensitive lines. The differences in water involved, usually less than 1-2 L per plants would represent a mere 10-20 mm of water on a field basis and would be difficult to detect with regular root measurements. This fully validates the value of our approach to look at root functionality rather than root morphology to gain further insight on their role to adapt to water limitation.

P 8.10 - Association study on drought-resistance and water-sensitivity of spring wheat Wu Z.L.1 (wzl4545@163.com), Lu Y.H.2, Fan L.1, Cai X.L.3, Li J.F.1, Fan Z.R.1, Zhang Y.Q.1 1 Institute of Nuclear & Biological Technologies, Xinjiang Academy of Agricultural Sciences, Urumqi

830000, China; 2 Plant Genomics Research Unit, INRA, Evry F91057, France; 3 Agricultural Sciences Institute of Xinjiang Farm 7th Division, Kuitun 833200, China. Xinjiang, China is the farthest wheat production region from ocean on earth with a typical arid climate. The annual precipitation is less than 200mm on the average. Usually, wheat production relies on irrigation. During 2004 and 2005, we studied the drought resistance and water sensitivity of 21 spring wheat varieties under the condition of water stress and full irrigation. The results showed that Xinchun2, Xinchun6, Xinchun7 and Xinchun10 were not only strong drought resistant but also quite sensitive to the soil moisture improvement. In fact, the planting area of Xinchun2 was the largest in Xinjiang from 1986 to 1995. Its productivity was 7.5 t/ha. The planting area of Xinchun6 was the largest in Xinjiang from 1996 up to the present. Its productivity was 9-10 t/ha. Xinchun10 was main cultivated variety in Tuokexun county where it is extremely hot with the most serious dry and hot wind in Xinjiang. Results also showed that there was a high significant positive correlation between drought resistance and water sensitivity among spring wheat varieties. But Xinchun11 was a special variety with low drought resistance and high sensitivity to the soil moisture improvement. Practically, Xinchun11 has been extensively planted in some counties where there are preferable irrigation condition and slight dry and hot wind. Its productivity was 9-10 t/ha. So that Xinchun11 has become a leading spring wheat variety. In the past, most of the researches about drought resistance rarely concerned water sensitivity. In fact, crop sensitivity to the soil moisture improvement is one of the most important physiological traits.

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AA Abbasov M. P5.01 Abdelhamid M.T. P3.01 Abdolrahmani B. P2.01 Abebe G. P2.02 Adibifard N. P3.02 Adu-Gyamfi J.J. P7.01 Afshari R.T. P4.01 Ahamadi J. P5.02 Ahmad S.T. P4.02 P4.03 Ahmadi S.H. P2.03 Alganesh Tesema G. P6.01 Al-Khateeb S.A. P3.03 Amamou A. P5.03 Amudha K. P6.02 Anithakumari A.M P5.04 Araus J.L. L4.09 Arunyanark A. P6.03 Asfaw A. P5.05 Atlin G.N. L6.02 Audebert A. P6.04 Awan S. P4.04

BB Babu R.C. P6.05 Badu-Apraku B. L6.16 Bantte K. P5.06 Barary M. P3.04 Barthakur S. P4.05 Bazargani M.M. P4.06 Bchini H. P3.05 Beena R. P5.07 Ben-Asher J. P7.02 Bencivenni C. P5.08 Beneventi M.A. P4.07 Bennett D. L6.04 Benor S. P7.03 Berger B. L7.06 Birru G.A. P2.04 Blum A. L9.01 Boken V.K. P2.05 Boopathi N.M. P6.06

Borrell A.K. L5.03 Boyer J.S. L9.02 Brestič M. P4.08 Bueno C.S. P3.06 Byrne P.F. P5.09

CC Cabrera-Bosquet L. L7.11 Çakir M. P5.10 Chapman S.C. L6.13 Chaves M.M. L4.07 Chen X. P5.11 P8.01 Cheng J.F. P7.04 Chenu K. L7.05 P6.07 P7.05 Christopher J.T. P5.12 Conaty W.C. P2.06 Condon A.G. L6.07

DD Daneshian J. P3.07 Daneshmand A. P2.07 Davies B. L8.02 P4.09 Deguchi T. P3.08 Diop N.N. P5.13 Dodd I.C. L3.10 Dodig D. P6.08 Dreccer M.F. P4.10 Drikvand R. P6.09 Du T.S. L2.07 Duan B.H. P7.06

EE Eberius M. P6.10 Eini O. P4.11 Engels C. P7.07

FF Falalou H. P5.14 Fang X.W. L3.03 Farquhar G. L1.01 Faye I. P6.11 Fayyaz F. P3.09 Feng F.J. P3.10 Fereres E. L2.06 Flagella Z. P4.12

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Foulkes J. L7.04 Fu Z.Y. P4.13 P3.11 Fujii M. P3.12

GG Gan Y.T. P2.08 P2.09 Ghamarnia H. P2.10 Ghanem M.E. P3.13 Ghobadi M. P3.14 Girdthai T. P6.12 P6.13 Govaerts B. L8.03 Gowda R.P. V. P3.15 Granot G. L5.04 Grieu P. P7.08 Guan D.M. P4.14 P6.14 Guan Y.S. P6.15 Guo Z.S. P2.11 Gupta V. P8.02

HH Habash D.Z. L4.14 Habibi D. P3.16 Haghighi L. P3.17 Hammer G. L7.01 Han L.Q. P8.03 Hao Z.F. P5.15 P5.16 Hauptvogel P. P4.15 He J. P3.18 Heard J. L5.05 Henry A. P3.19 Hittalmani S. P6.16 Hochholdinger F. L3.07 Hossain M.A. P4.16 Hossain M. I. P2.12 Hu S.P. P5.17 Hu X.J. P4.17 Hua H.P. L5.07 Huang C.Y. L7.08 Hummel I. L4.01 Hussain S. P3.20

II Imene T. P4.18 Inagaki M. P3.21

Islam M. R. P2.13 Iwama K. P6.17 Iwasa T. P6.18

JJ Jahanbakhsh S. P7.09 James R. L7.09 Javid M.G. P4.19 Jensen N.L. P4.20 Jia W.S. P4.47 Jian M. P7.10 Jing R.L. L6.05

KK Kamoshita A. P5.19 Kang Y. P4.21 Kano M. L3.08 Kato Y. L2.09 Katsura K. P2.14 Kenzhebayeva S.S. P6.19 Kershanskaya O.I. P4.22 Khan N. P4.23 Kholová J. P5.20 Khowaja F.S L4.05 Kijoji A.A. P3.23 Kim Y.H. P4.24 Kirkegaard J. L2.02 Klein J. D. P3.24 Kottapalli K.R. L 4.15 Krugman T. P4.25 Kumar A. P7.11 Kumar J. P6.20 Kumar P.R. P3.25 Kumar S. P5.21

LL Labhilili M. P5.22 Lal J.P. P6.21 Landi P. P5.23 Lang N.T. P5.24 Langridge P. L8.01 Larqué-Saavedra A. P8.04 Latiri K. P2.15 P3.26 Levi A. L6.03

238

Li J.T. P4.26 Li Z.K. L 5.01 Liang Y.L. P3.27 Liu C.H. P7.12 Liu F.L. L3.05 Liu H.Y. P5.25 Liu S.H. P4.27 Liu X.M. P6.22 Liu Z.C. P5.26 Lobet G. P7.13 Lü L.H. P1.01 Lu Y.L. P5.27 Luo L.J. L5.02

MM Ma Z.M. P2.16 Maccaferri M. L5.09 Mafi-Moghaddam S. P5.28 Magorokosho C. P6.23 Mahmood-ul-Hassan M.A. P2.17 Makdis F. P6.24 Mäkelä P. P3.28 Makumbi D. P6.25 Malidareh A.G. P2.18 Mamedova A.D. P6.26 Manavalan L.P. P6.27 Mao X.G. P4.28 Maragatham N. P2.19 Matichenkov V.V. P8.05 Maurel C. L4.12 Menkir A. P6.28 Merewitz E. P4.29 Meseka S.K. P6.29 Messina C. L7.02 Min Q.U. P5.29 Mirassón H. P2.20 Missihoun T.D. P5.30 Mitchell J.H. P3.29 Mkamilo G. P6.30 Mohammadi-Nejad G. P3.30 Molinari H.B.C. P4.30 Moragues M. P3.31

Munjal R. L4.08 Munyiri S.W. P6.31 Mushtaq R. P4.31 Muza O. P2.21

NN Nagaveni B.H. P4.32 Naji M.Z. P6.32 Nakhoda B. P3.32 P3.33 Naredo M.E.B. P5.31 Nejad S.D.B. P2.22 P3.34 Nemati I. P3.35 Nethra N. P5.32 Nguyen H.T. P5.33 Nhlane G. P6.33 Nsarellah N. P6.34 Nucci E.D. P3.36

OO Ober E.S. L7.10 Odilavadze T.V. P2.23 Okami M. P3.37 Oliver M. L4.13 Omar S.A. P2.24 P6.35 Oosterom v. E. P7.14 Outoukarte I. P6.36 P3.38 Ozfidan C. P4.33

PP Pan Y.J. P5.34 Parameshwarappa K.G. P6.37 Parry M.A.J. L4.02 P4.34 Patil K.G. P6.38 Patil S.B. P6.39 Paytas M. P3.39 Peleg Z. P4.35 Peng S.Q. L1.03 Pérez-Pastor A. P2.25 Plauborg F. L2.03 Ponnuswamy K. P2.26 P2.27 Poornima R. P6.40 Puangbut D. P6.41

QQ Qu M. P4.36

239

RR Rachaputi R.C.N. L6.15 Rafiei M. P3.40 Ramachandrappa B.K L2.04 Raman R. P3.41 P8.06 Ramegowda H.V. P4.37 Rane J. P8.07 Rangaiah S. P6.42 Rao I.M. L6.14 Rashidi V. P6.43 Rebetzke G.J. L6.01 Rebolledo M.C. P7.15 Rivero R.M. L4.10 Rodrigues F.A. P5.35

SS Sadeghi S.M. P6.44 Saeed M. P5.36 Sage R. L1.04 Saif A.A. P6.45 Salunkhe A.S. P6.46 Samdaliri M. P3.42 Sarkar K. K. P3.43 Sayar R. P6.47 Sehgal D. P5.37 Sellamuthu R. P5.38 Senthil A. P6.48 Serraj R. L7.03 Setter T.L. P4.38 Shamsi K. P2.28 P3.22 Shan L. L2.05 Shanker A.K. P4.39 Sharma A.D. P4.40 Sharma A.K. P6.49 Sharma P.C. P6.50 Sharp R.E. L3.06 Shashidhar H.E. L6.08 Shehrawat P.S. P7.16 Shinde S.S. P5.39 Shu L.B. P5.40 Sine B. P7.17 Singh A.K. P6.51 P7.18

Slabbert M.M. P7.19 Soud A.R. P5.41 Soundharajan B. P7.20 Spencer M.M. P4.41 Sreenivasulu N. L6.12 Steduto P. L2.01 Steele K.A. P6.52 Suárez R. P4.42 P5.42 Suji K.K. P6.53 Sweeney P. P7.21

TT Tahir M. P4.43 Tarafdar P.K. P2.29 Tardieu F. L3.01 Taware S.P. P7.22 Thompson A.J. L3.09 Tikle A.N. P6.54

UU Uchua K.A. P8.08

VV Vadez V. P3.44 P8.09 Valentinuz O. P3.45 Valliyodan B. L5.06 Vankova R. L3.11 Varillas m.A. P4.44 Venuprasad R. L6.09 Vikram P. P6.55

WW Wade L. L3.04 Wang C.M. P5.43 Wang C.X. P4.45 Wang D. P5.44 Wang H.Q. P6.56 Wang J.K. P5.45 Wang J.X. P3.46 P3.47 Wang M.C. P2.30 Wang Y. P4.46 Wang Y.S. P3.48 Waraich E.A. L2.08 White C.A. P3.49 Wilson P. B. P4.48

240

Wu Z.L. P8.10

XX Xiang C.B. L4.06 Xin Z.G. P3.50 Xiong L.Z. L7.07 Xu C.P. L4.11 Xu W. P4.49 Xu Y.B. L6.10 P7.23 Xu Z.S. P4.50

YY Yadav O.P. P6.57 Yadav R.S. L6.06 Yan J. P4.51 Yan J.B. L6.11 Yang D.L. L5.08 Yang J.C. L3.02 P3.51 Yang Y.Y. P2.31 Yousfi S. P4.52 Yu S.W. P7.24 Yuliasti P6.58

ZZ Zarei G. P3.52 Zhang H.Y. P4.53 Zhang J.A. P5.18 Zhang Q.F. L1.02 Zhang Z.B. P6.59 Zheng T.Q. P5.46 Zhou Y. P6.60 Zhu J.K. L4.03 Zhu K. P2.32