Assessing trends in genetic diversity to inform in situ conservation strategies for crop wild relatives Thormann I, Fiorino E, Dulloo ME 4th International Symposium on Plant Genetic Resources: Genetic Resources for Climate Change at 29th International Horticultural Congress, 17 - 22 August 2014, Brisbane, Australia

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Crop wild relatives are increasingly important for present and future agricultural development, as theyprovide adapted genes and traits for crop improvement, even more so under changing climate.

(Hajjar and Hodgkin 2007; Maxted et al. 2012, McCouch, 2013; Dempewolf et al, 2014, etc)

Crop wild relatives (CWR)

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• To allow for crop wild relatives populations to continue to evolve in their natural habitats and adapt to changing environmental conditions;

• To capture the evolving traits in crop wild relatives that might be useful for plant breeders and farmer for current and future use

Why is in situ conservation of crop wild relatives important?

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• Overview of diversity and current conservation/threat status • Prior knowledge about population structure, demography,

distribution of genetic diversity in target species across their areas of occurrence;

• Access to these information is important to develop in situ conservation strategies management plans and Strategic Action Plans

• Inform policymakers of what conservation interventions are required for effective management and monitoring of target populations

Developing in situ conservation strategies

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• Requires knowledge about existing diversity • Temporal dimension: at least 3 data points are needed or

historical information known• Potential sources:

Plant germplasm collectionscan provide past snapshotsof diversity and data for re-collection for assessmentof current diversity

• One example: Bioversity International’s collecting missions database

Assessing and monitoring trends and loss in genetic diversity

http://bioversity.github.io/geosite/

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• 27% of collected samples are wild species

• 25% of trips collected only wild species

• Passport data and collecting mission reports for most samples available

Bioversity International collecting missions database

• 1000 collecting trips between 1975 and 2012• 226,618 samples collected, of which ca. 85% between 1975-

1995

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• 60,000 (27%) of collected samples are wild species collected from 115 different countries

• 73% of wild samples are geo-referenced

• Numerous examples of – groups of species collected from

the same country– single species collected from

several countries

Crop wild relatives’ samples in Bioversity International’s Collecting Database

53.20%

10.40%

9.40%

7.60%

7.60%

11.80%

Forages Cereals Legumes

Roots and Tubers Vegetables Others

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CWR samples in Bioversity International’s Collecting Missions Database

Note: shows only species for which more than 50 geo-referenced samples were collected during a collecting trip

Group of species collected from same country: forage legumes in Syria

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CWR samples in Bioversity International’s Collecting Missions Database

Note: shows only species for which more than 50 geo-referenced samples were collected during a collecting trip

Single species collected from several countries: Prosopis africana in Africa

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Potential applications Fills data gap for CWR diversity assessment studies

Unique link between original passport data, additional collecting documentation and genebank accession numbers allows to:

• Identify coherent set of samples/sites collected at the same time/way (historic snapshot of diversity)

• Re-visit old collecting sites and re-sample CWR

• Retrieve original material in genebanks

• Assess temporal variation in genetic diversity and current vulnerability and threat

• Inform conservation actions

• Comparative studies among species and different eco-geographic realities

• Investigate effects of climate change

Original passport data

corresponding genebank accession

original collecting

documentation

• No changes in varietal diversity at national level• Significant shift in adaptive traits: shorter life cycle, reduction in plant

and spike size

Example

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• In 2012 re-visited the sites where wild barley and LRs were collected in 1981– Verified collecting sites based on

coordinates and location description– Re-collected wild barley from 32 old sites– Collecting of wild barley samples also from

additional sites in reserves– Re-collected landraces from 26 old sites

Successful implementation: re-collection of barley in Jordan

Verification with Google earth and gazetteers

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Tracking of 1981 samples: distribution and conservation of samples in genebanks

ICARDASyria

NordGenSweden

NCAREJordan

July 1982LR in1981; CWR in 1982; about 50-60 g/acc

repatriation after 1996; 100 seeds/acc?

R = 1- 2LR in 1985 or 1996;CWR in 1994. R = 2 for some CWR

R = 0never integrated in collection, kept in freezers

R = 0

R = regeneration or multiplication cyclesLR = landraceCWR = crop wild relative

IPKGermany

transfer in 2012

Jordan?

??

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Common garden in IPK – growing season 2013

• Growing season 2013

• Wild barley and landrace samples from 1981and 2012 + 5 control accessions

• Leaf tissue and phenotypic trait data collectionon 16 individuals per accession

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Preliminary results from re-collecting trip and common garden

• In most sites wild barley populations are still there, however – at the Eastern border of the collecting area some sites have become too dry

(both for wild barley and landraces)– Small residual populations where barley cultivation is abandoned due to land

use change or change from cereal cultivation to orchards– Barley still growing on field margins of barley fields like in 1981

• Wild barley populations thrive better in disturbed habitats, significantly smaller in undisturbed habitats.

• Wild barley populations are taller and have more tillers in 1981 compared to 2012

• Growth habit is prevalently prostrate in 1981 while intermediate growth habit dominates in 2012 samples.

• No significant difference in days to heading and maturity

• Molecular markers studies on all the samples and accessions are currently ongoing

Thank you