Independent selection for seed free tryptophan content and vernalization response in chickpea domestication

Chickpea shows a distinct domestication trajectoryvis-a-vispod dehiscence andgrowth cycle mediated by vernalization insensitivity compared with its companionNear Eastern legumes. Our objectives were: (i) to map the quantitative trait loci(QTLs) associated with vernalization response and seed free tryptophan in domesti-cated9wild chickpea progeny and (ii) estimate the genetic correlation betweenvernalization response and free tryptophan content. A domesticated9wild chick-pea cross was used to document phenotypic segregation in both traits and to con-struct a skeletal genetic map for QTL detection. A number of vernalization responseand seed free tryptophan content QTLs were documented in both F2and F3gener-ations. No significant genetic correlation between these two traits was observed.Epistatic relationship between two free tryptophan loci was documented. It is evi-dent that selection for high seed tryptophan is easier to accomplish relative toselection for vernalization insensitivity. This suggests that the two traits were selected independently in antiquity, thereby corroborating earlier claims for con-scious selection processes associated with chickpea domestication