Molecular Mapping of Drought Tolerance Genes in Cowpea (Vigna unguiculata L. Walp).

Cowpea (Vigna unguiculata L. Walp) is a leguminous crop that many people around the world rely on to meet their basic nutritional needs. Both humans and livestock consume the protein and fiber rich grain and vegetative matter of the cowpea plant. Water stress affects this crop like many other crops; by reducing total biomass and grain yields. Genotypes of cowpea have been identified that contain genes that confer tolerance to drought.  In order to map the quantitative trait loci  (QTL) associated with the drought tolerance traits, a recombinant inbred line population (RIL) was created from the parental genotypes IT98K-476-8 and ‘Golden Eye Cream’ (GEC). This population was phenotypically analyzed for drought response. The genes conferring the drought tolerance were mapped using restriction site-associated DNA sequencing (RAD-seq) and SNP markers closely linked to the genes of interest were identified.  With this knowledge of the underlying genetics regulating drought tolerance in cowpea, molecular tools can be created which will further help in the breeding of more drought tolerant species.