Morphological and physiological adaptation mechanisms of sorghum to latudinal and precipitation gradients in Mali By Alhassan Lansah Abdulai PhD Student University of Hohenheim Under the Framework of the Project Developing rice and sorghum crop adaptation strategies for climate change in vulnerable environments in Africa – RISOCAS

Outline of Presentation Climate Change Issues Predicted Trends of Climate Change Predictions Being Experienced Sorghum Issues Objectives Expected outputs Methodology

Climate Change Issues  Climate change threatens staple food production and human livelihood, particularly in vulnerable environments of Africa.  Food supply and income of local farmers are dwindling, thus worsening the states of both poverty and hunger in these areas.  Article 2 of the Kyoto Protocol raises concerns about effects of climate change on the production, access, and distribution of food.

Predicted trends of impacts on agriculture  warming is very likely to be higher in Africa than the global mean (IPCC, 2007)  Benefits may accrue for temperate agriculture (FAO 2002)  Tropical agriculture may suffer (FAO 2002)  Global inequities in production potential may deepen (FAO 2002).

Predictions being experienced  Increased variability of seasonal rainfall amount and distribution (IPCC 2001; Fischer et al., 2002; Wang 2005)  Increased occurrence of (and vulnerability of crops to) drought and flooding (IPCC 2001; Fischer et al., 2002; Wang 2005).  Optimal crop growing zones have shifted and regional food production potentials altered under this forecast (UNEP, 2006).

Sorghum Issues  Rainfed sorghum is one very important source of staple small-grain cereals in Sub-Saharan Africa.  Seasonal climatic patterns influence the phenology, growth, water use and attainable yield of sorghum  Locally adapted genotypes are currently available  Unpredictability of the changing climate calls for new and adapted genotypes  Appropriate crop calendars and management options for the altered conditions required for minimal effects of biophysical risk factors

Genotypic traits of adaptations investigated Phenology of sorghum (including photoperiodism) Carbohydrate partitioning Physiological drought and salinity Morphological responses to drought and salinity Genotype x Environment interactions Full range of adaptation mechanisms under full range of expected climate change scenarios not addressed yet.

Plant survival hinges directly on water economy under such conditions Mechanisms for water acquisition and reducing water loss need to determined Roots play an important role in water and nutrient acquisition Leaves play an important role in water loss Knowledge of the following are essential changes in root morphology of sorghum in response to water- and/or temperature-related stress.

Alterations in leaf-level gas exchange in response to water- and/or temperature-related stress Patterns of assimilate partitioning with particular focus on root properties under water- and/or temperature-related stress

Specific Objectives of the work Investigate the possible genotypic adaptations to diverse environments Determine the patterns of assimialte partitioning under diverse environments Quantify changes in root morphology under different environments Characterize the genotype-specific leaf level responses to different climates

Expected outputs:  Patterns of assimilate partitioning with particular focus on root properties under water stress identified for at least 10 sorghum genotypes  Genotype-specific, leaf level stress responses particularly stomatal conductance and photosynthesis characterized.

Methodology Field trials will be established with staggered planting dates replicated in 2 years at the various sites to provide a large diversity of weather patterns for the crops, needed to capture the diversity of potential climate change scenarios Focus on morphological adaptations for water acquisition and/or reduction of water loss in rainfed sorghum.

Morphological adaptations comprise  deeper rooting under water deficit conditions, reduction of transpiring plant surfaces,  stay-green syndrome. Adaptations in carbohydrate allocation are important for these traits. 10 genotypes will be investigated (these are still being assembled)

Sites  Segou (Cinzana),  Bamako (Sotuba),  Sikasso (Farrako) To represent latitudinal and precipitation gradients Planting dates  Segou 4 (June-September  Bamako 4 (June to September)  Sikasso 6 (May to October)

Weather Parameters to be monitored Precipitation Air temperature Solar radiation Air humidity Wind speed Monitoring Soil moisture on all plots Tube Probe TDR Calculation of seasonal dynamics of plant available. Bare soil evaporation will be monitored by mini- lysimeters.

Phenological phases to be recorded. Germination Tillering Panicle initiation Internode elongation Booting Head Exsertion Flowering, Physiological maturity

Other Parameters to be recorded at each site Phyllochron Plant height Above-ground biomass (separated into prop roots, stem, leaf and inflorescence) Below ground biomass Specific leaf area Yield (including yield components and harvest index).

Dry matter partitioning will be determined in 4-week intervals for all genotypes and plots. Belowground net primary productivity, rooting intensity and depth of rooting will be determined from soil auger samples and mesh bags. Leaf samples for 12 C/ 13 C analyses will be taken  5-leaf-stage,  panicle initiation,  early flowering.

stomatal conductance photosynthesis SPAD leaf water potential leaf area (for all the leaf levels).