Genetic tools and knowledge for cassava productivity and special uses

1. What is the status of cassava production and how did we get here?

2. Lessons learned along the way3. Where do we want to go from here?4. What are the tools, knowledge and systems that we

going to employ to get us there?

Intercropping

Weeds

Degraded soils

Traditional cultivation

Fundamental for food security

Low fertility

Low but stable yields

Development of management packages and new varieties for high and efficient productivity has a history of almost 40 years in IARCs and longer in

some NARS

Management + Genetic Improvement

Commercial planting in sub-humid conditions

Commercial planting in acid soils

Well managed cassava

Fundamental for income generation and rural development

1. Status of technology

• Applied breeding techniques well established• Flow of improved varieties for many regions and

markets• Optimum management packages (soils/agronomy)

defined for many regions and systems• Steady yield increases in many countries• Molecular tools advancing rapidly

Global yield trends (t/ha) for cassava

1961 1970 1980 1990 2000 20090.0

5.0

10.0

15.0

20.0

25.0

Asia

AmericasWorld

Africa

Source: FAOSTAT

Yield trends (t/ha) in six cassava-producing countries

1961 1970 1980 1990 2000 20090.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

Source: FAOSTAT

India

Thailand

BrazilColombiaNigeria

DR Congo

Yield trends - overview

• 30-40 t/ha is possible under very good management in many environments

• 70-80 t/ha is possible in exceptional conditions

• Cassava is rapidly diverging into a traditional crop for food security and an industrial crop

However . . . • Many people believed that by the 90s,

national programs would be able to take over most breeding functions and IARCs could focus on upstream and strategic research; trait discovery for deployment by NARS.

• By the mid 90s, the effects of cutbacks in the system were becoming evident

New Cassava pests and diseases

• Mealy bug• Whitefly• Other

diseases

Emerging problems for Cassava in Asia: The need for continued vigilance

Critical contributions of the Americas

• Diversity of cultivated cassava• Diversity of wild species• Diversity of pests and diseases• Diversity of bio-control agents

New challenges: Impact of climate change oncassava suitable environments

Global cassava suitability will increase5.1% on average by 2050… but many major areas of current production suffer negative impacts

Source: A. Jarvis, CIAT

2. Lessons learned An overview

• Sustained investment in research pays off• +/- 20-year lag between initial research investment and

substantial returns for breeding + management technology• Genetic improvement and management contribute more or

less equally to yield gains• Integration of production and market demand . . . markets drive intensified management• Most countries are not anywhere close to yield potential• There is no status quo – the world evolves and research

efforts need to keep up

What do we want to be able to offer in the next 20 years?

• to growers• to processors and consumers

What do research organizations need to do to deliver these products?

3. Where to from here?

3. What growers need

• High yield potential in a wide range of environments• Effective management of biotic and abiotic constraints• Cost-effective, eco-efficient crop and soil management

practices

• Plant traits that enable efficient management• Efficient propagation systems• Root traits with a ready market

3. What processors and consumers need

• Year-round access to a uniform, quality product at a fair price

• Specific starch traits• Good post-harvest storage• Ease of processing (root form, peel traits, fibre

content)• High efficiency of conversion (according to specific

end-uses)

4. How are we going to get there?Challenges and Opportunities

• “Africa has only 70 scientists per million inhabitants compared to 4380 scientists per million inhabitants in Japan”

Dr Papa Abdoulaye Seck, Director General of the

Africa Rice Center (WARDA)

4. How are we going to get there? Challenges and Opportunities for the research community

4. How are we going to get there?Challenges and Opportunities for the research community

• Serious decline in funding in last 20 years• Many once-strong NARS cassava programs have made

serious cutbacks in personnel and operations• Training of the new generation has lagged• Few national programs able to produce/manage crosses

(About 50,000 – 100,000 seeds managed for every successful new variety developed)

• In CGIAR – the trend away from interdisciplinary core-funded teams to special projects

• Limited private sector support in most countries

4. How are we going to get there?Challenges and Opportunities for the research community

• Train young staff with advanced degrees• Commit to long term support for research• A system that fully integrates management and

genetic improvement• A system that fully integrates molecular tools with

plant breeding• Work to develop market demand

Research efforts to increase cassava productivityGenebanks: The principal resource for breeding

Cassava Biodiversity

Wild Manihot species are unique sources of genes that could be used through breeding with marker assisted selection, and/or genetic transformation

BUT:search first in M. esculenta

M. Bonierbale

Cassava Genomics ToolsMapping Tools

- Several mapping populations linked to breeding- ~ 450SSRS, 301 AFLP-RFLPs, 17 Genes- MAS for CMD and Post Harvest Deterioration- New gene based microsatellite markers identified at CIAT (1391) in

2008 and at USDA –IITA (846) in 2009- SNP markers being developed at CIAT, U. Arizona, U. Maryland and

U. Pretoria

BAC Libraries- 3 libraries with 5X, 10X, and 11X coverage- Deposited at Clemson Genome Center- Used so far by CIAT and EMBRAPA

Cost of whole genome sequencingView in 2009

1995

1998

2005

2010

2015

10,000,000,000

1,000,000,000

100,000,000

10,000,000

1,000,000

100,000

10,000

1,000

100

May 19, 2009: $1 Per Gene, Knome Launches $24,500

Genome Service1000 $ Genome

Adopted from Chan(2005), Mutation research.573:23-50)

June, 2007: Watson Genome -$2 Million. 454 technology

Complete Genomics (2009 ) - $5,000

• Organizational• Technical

4. The way forward

4. Organizational

• Move from project mode to integrated program mode for core activities (basic breeding, agronomy, pest management)

• Participatory centralization for germplasm management• A world genebank that can be freely exchanged (also technical)• Revitalize national program capacity in conservation, breeding and

“seed” systems• A molecular platform that includes broad developing country

participation (e.g. the Integrated Breeding Platform of GCP)• Involve private sector to a greater extent

Building capacity for sustainable success!

4. Technical

• Breeding capacity

• Phenotypic characterization

• Access to genomics facilities

• Bioinformatics capacities

• Low cost rapid propagation expertise

• Capacity to transfer genes from cassava to specific genotypes (cisgenic products)

• Development of transgenic products and how to manage the whole process

• Access to biosafety fields

Rapidly Evolving Technologies

Phenomics Genotyping GM Microarray Proteomics Sequencing

CGIAR and Regional Infrastructures

Reducing costsAccess to technologies

Accelerate breeding

Integration with germplasm banks

Integration with breeding

Breeding can be made much more efficient , but . . .

The need for multi-location, multi-year advanced testing (3 yrs?) places a lower limit.

Traits for added value

Variation in crude protein content of roots of 133 cassava clones

Fuente: Teresa Sánchez

1.00

1.20

1.40

1.60

1.80

2.00

2.20

2.40

2.60

2.80

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97 101 105 109 113 117 121 125 129 133

Sq

rt (%

pro

tein

)

Genotype

1.4

2.0

2.6

3.2

4.0

4.8

5.8

7.8

Crud

e pr

otei

n co

nten

t (%

) DM

bas

is Farmers produce cassava with 30% added value. Stronger market demand

Reducción en el deterioro fisiológico de postcosecha enel híbrido inter-específico M. esculenta x M. walkerae

(14 días luego de la cosecha)

MCOL 1505: 27.8%

MBRA 337: 9.48%

CM 523-7: 51.9%

CW 429-1: 0%

Fuente: C. Egesi

Average % amylose in the starch: 0.0-2.9%

Fuente: Fernando Calle / Nelson Morante

“Waxy” maize has an added value of about 30% in the marketplace

Stems

“Waxy” cassava

Fuente : José A. Arroyave

Normal grains

Small grains

Grains with cavities

Ease of access for enzymes

Reduction in fermentation costs

Summary:What’s limiting progress in breeding?

• Low support to NARS/CGIAR for cassava R&D• Constraints on international shipment of

germplasm (esp. LA to Africa)• Integration of molecular tools with field breeding• Success with dihaploid technology – trait

discovery; deleterious recessives; breeding systems• Ability to induce flowering – produce more crosses• Regulatory environment for transgenics• Targeted gene insertion via cisgenics

How?

• Developing capacity in national programs• A long-term vision within the CG• Developing markets that drive demand• Public-private alliances• North-South collaboration

TEAMS + TOOLS + TIME

THE VISION: Harvesting the sun -- A multi-purpose crop that meets the needs of food security and income generation for growers . . . and food, feed, fuel and diverse industrial uses in the marketplace, through eco-efficient management systems.