Overcoming interspecific barriers in Sorghum and molecular characterization of the derivatives

Crop improvement in sorghum has progressed extensively availing the variation available in the primary gene pool of S. bicolor. Crossing further, the yield plateau can be accomplished by bringing in the genes from tertiary gene pool into the cultivated gene pool. Earlier efforts for wide hybridization in sorghum with tertiary gene pool were not successful due to inhibition of wild pollen germination on the stigma of cultivated species. In the current study, elite lines of cultivated Sorghum species were pollinated with wild species using different floral treatments. The results showed that spray with the synthetic auxin, 2,4-dichlorophenoxyacetic acid, has promoted the seed set. Overall, 76% crosses showed seed set, but many seeds were underdeveloped and deformed. F₁ progeny showed traits of both cultivated and wild parents. Hybrids were confirmed through PCR analysis. Many (80%) F₁ plants were sterile, and 20% of F₁s were advanced to F₂ generation. Wide variation was observed in F₂ progeny, and the phenotype selections were made and are being evaluated in the field.