Assessment of Genetic diversity in Sesamum indicum by EST-SSR: problems and prospects

Aim of this study was to assess the genetic diversity in the cultivated sesame germplasm using expressed sequence tagged - simple sequence repeat (EST-SSR) markers. Of the thirty-four EST - SSRs tested nine revealed polymorphism. Four genomic - simple sequences repeat (G-SSR) tested additionally, however, showed almost cent percent polymorphism. In total there were sixty-seven EST SSR bands and thirty-seven G-SSR bands were obtained. PIC value of the polymorphic primers ranged from 0.45 to 0.85. Blast analysis of the primer sequence with the available sesame genome sequence revealed association of the chosen SSRs with gene regions encompassed with metabolic functions. The selected SSRs were found to spread over all the linkage groups excepting the linkage groups 9 and 13 of sesame available, with some of them associated with more than one linkage group. Lack of polymorphism for several of the SSRs confirmed that the genomic regions covered by them are highly conserved. It is concluded that inclusion of additional markers in the analysis may lead to a complete understanding of the genetic structure of Sesamum that would be useful in its breeding.