Posted on Dec 01, 2009
This proposal is focused on supporting increases in the yield and yield stability of sorghum through research, specifically on the topic of development and deployment of water management and water use efficiency. The decision to grow sorghum is frequently based on its drought tolerance. The importance of drought tolerance in agriculture is likely to grow—agriculture uses 69% of the world’s available water supply, and 46% of available water in the USA. Many parts of the world, including some parts of the USA, face “water scarce” conditions in the future. The development of drought-resistant crops by conventional breeding has been hampered by low heritability, and by large ‘genotype x environment’ interactions. Conventional sorghum breeding has only utilized a small subset of the available germplasm—we hypothesize that a substantial degree of phenotypic variation in responses to drought exists and remains among a broad sampling of sorghum genotypes.
The proposed activities build upon a detailed physiological and agronomic characterization of a ‘diversity panel’ of 384 geneotypes that broadly samples worldwide sorghum diversity, let by our cooperators H. Upadhyaya (germplasm curator), v. Vadez (plant physiologist), and C. T. Hash (sorghum breeder) at ICRISAT. Numerouse –omics approaches offer the means to develop testable hypotheses about possible relationships between specific genes or gene families and drought response. Our work will identify specific genes, DNA markers, and possibly even nucleotides, that are diagnostic of particular drought responses.
These DNA markers may accelerate progress in sorghum improvement through either marker-assisted selection or through identification of specific genes that make singularly large contributions to sorghum drought tolerance. Because the diversity panel to be studied broadly samples worldwide sorghum diversity, molecular-level results are expected to have a very broad relevance to the sorghum gene pool generally, and phenotypic results are expected to identify a broad sampling of drought tolerant germplasm, different subsets of which are likely to be adaptable to different regions. The benefits of using such germplasm lines might be determined quickly, by their evaluation in hybrid combinations with wiedly-used inbreds already adapted to respective target regions.