1 • 3/21/11
Breeding strategies
Workshop Ethiopia
6-8th of December 2011
2 • 3/21/11
Breeding strategies on which crops?
Sorghum
Bean
Banana
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Sorghum
Area harvested of sorghum
Intensively grown in the borders between
Niger and Nigeria and in West India

Monfreda et al., 2008
Which are areas of high suitability
Current sorghum suitability
Ramirez-Villegas et al., 2011
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Sorghum x:
Genotype of high
temperature is
sensitive to
What’s the principal constraint for Sorghum?
Sorghum n:
Genotype of low
temperature is
sensitive to
2 main current climatic
constraints
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Sorghum suitability changes by 2030
Central Ethiopia
Uganda
SE Kenya
Tanzania
Negative impact: Central Ethiopia, Uganda, SE Kenya, Tanzania
 50-80% of suitability area could decrease in climatic suitability
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Adaptation before negative impacts
Simple strategies of adaptation to minimize sorghum yield losses
–
–
–
Delayed sowing to avoid water stress
Crop substitution
Expansion to new agriculturally suitable areas since some environments with
particularly low temperature will likely become suitable in the future, such as the
highlands of the semi-arid tropics.
HOWEVER
Biological adaptation of Sorghum are needed
-
The sorghum genetic pool contains a wide range of traits
Important abiotic traits in terms of sorghum adaptation in Sub-Saharan Africa and
India: growing cycle duration and drought tolerance.
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Banana
One of the world’s major food crops
Current banana suitability
Where banana suitable?
Most suitable area located in
tropical humid regions
 Coinciding with the current
distribution of the crop
Area harvested
 Low lands in Latin America,
the Caribbean, western Africa,
RDC, CAF and in southern
Asia
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What’s the major climate constraints for
banana?
: up to 20% of global
suitable areas: N India, N Myanmar, Laos, N
Vietnam, S Africa
Limited by low rainfall: Atlantic coast of Latin
America, northeastern Brazil, the Sahel, central
Tanzania
Major climate constraints in most areas =
WAF: West Africa, EAF: East Africa, CAF: Central Africa, IGP: Indo-Gangetic plains, AML: Latin America
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How will change the suitability of banana
in the future?
Prediction of Area positively impacted
Area limited by min temperature and rainfall will be favored
in the future
 East Africa, Southern Africa, Sub-tropical Brazil,
Paraguay, Northern Argentina,…
 Projected climate of the 2020s is expected to favor
increased banana production in some areas by up to 50%.
Prediction of Area negatively impacted
- South America
- West and central Africa
 Decrease of banana suitability due to
drought
 Poor fruit development
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How adapting the sector to climate change?
- Measures to manage impacts need to involve agronomic practices as
well as the development of more resilient hybrids and with fruit quality
that is acceptable to markets
 Increased tolerance of drought and temperature extremes,
- Banana resistant to Black Sigatoka which is the most widespread
disease of bananas
HOWEVER CC could
have positive impact
to reduce Black
Sigatoka. Black
Sigatoka will be less
suitable in the most
areas
11 • 3/21/11
Area harvested
Current bean suitability
Bean
The most important food legume in tropical Latin America
and East and southern Africa
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Which climatic constraint affects the most beans?
Major climate constraints:
heat stress
drought stress
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Changes in Beans Suitability
• Average global area of suitability for growing beans may be
reduced by 6.6% by 2020
• But wide range of change in suitability from -87% to +66%
across regions.
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•
Potential breeding strategies
Breeding drought resistance into bean
– 3.9 million ha of current bean area more suitable
– 6.7 million ha currently not suitable would be suitable
•
Breeding heat tolerance into bean
– 7.2 million ha of current bean area more suitable
– Increase highly suitable areas by some 54%
Expected impacts of breeding technologies in bean. Reduced susceptibility
to drought (left) and improved heat tolerance (right) were found to have the
greatest impact on suitable, marginal and unsuitable areas.
Drought resistance and
heat tolerance
= Important objectives for
genetic improvement
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Potential breeding strategies
• Adaptation to drought stress
– Fitting the right root system to each production environment:
Deeper root system – Root whorls – basal root
 Improved genotypes with vigorous root systems
– Stomatal control
– Improved photosynthate remobilization under stress
• Adaptation to heat stress
– Tepary bean “Sonora 32” (P. acutifolius) = more tolerant of
high temperature at germination
Tepary bean
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•
•
Beans and CC impact on fungal, viral
disease and insect pests
Changes of precipitation and temperature can lead to the emergence of
some diseases and alter the distribution and severity of pathogens and
diseases
Increase in precipitation in many African countries for the 2020s:
- Beans more affected by angular leaf spot (caused by Phaeoisariopsis
griseola): Rwanda, Burundi and some regions of Tanzania, Uganda, Kenya,
and Malawi
- Beans could be more affected by anthracnose (caused by Colletotrochum
lindemthianum): Rwanda, Burundi, Kenya
- Root rot disease ( Pythium and Fusarium spp.): Rwanda, Burundi, Kenya,
and Uganda
•
Regions affected by drought
- Less prone to attack from fungal pathogens
•
Whiteflies- regions affected by whiteflies
- Find bean germoplasm resistant to whiteflies
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Potential for crop improvement
• Research in Breeding for drought-resistant beans: CIATColombia, EMBRAPA-Brazil, INIFAP-Mexico, ZamoranoHonduras
 Mesoamerican gene pool, study based on grain yield under stress
 Primary source of genes for drought resistance = Race Durango
 Race G21212 express substantial remobilization of photosynthates to grain
under drought + well-filled grain under stress
• Common bean genotypes adapted to heat stress: G122, G5273,
BAN26, Brio, CELRK, HT20, Venture, Negro Argel
 But need better yield  High temperature tolerance may be the biggest
challenge of adapting to climate change
 For now: tepary bean (P.acutifolius) have the most useful traits for drought
and high temperature
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Comparison of changes in crop suitability in
specific region
West Africa: Changes in
suitability of Sorghum are
positive => Potential
adaptation= focus on
sorghum crop
 Need genetic
improvement for Banana
and Bean
19 • 3/21/11
Comparison of changes in crop suitability in
specific site
Uganda: Changes in
suitability of Banana are
positive => Potential
adaptation= focus on
banana crop in this area
 Need genetic
improvement for Bean and
Sorghum
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Comparison of changes in crop suitability in
specific site
Indo-Gangetic Plains:
Any of the 3 crops
would be positively
impacted by CC
 Need to find other
crops or search other
type of variety which
would be suitable in the
future climate