Molecular Characterization and Assessment of Genetic Diversity in Sesame (Sesamum indicum L.) Germplasm Collection Using ISSR Markers

Sesame (Sesamum indicum L.) is an important oilseed crop. Breeding programs in this crop are mostly based on selection hybridizations, and mutations. The present studies were conducted to establish genetic diversity in a morphologically and geographically diverse sesame germplasm (94 accessions). This was achieved through DNA polymorphism generated by a set of 34 confirmed polymorphic inter-simple sequence repeat (ISSR) markers. Allelic data were subjected to neighbor-joining-based clustering analysis using Paleontological Statistics (PAST) software version 2.11. The resultant dendrogram assigned the 94 genotypes to five clusters, all of mixed heritage. The dendrogram did not suggest any correspondence among pedigree, breeding center, or geographical origin of the accessions. Natural out-crossing in germplasm collection has possibly resulted in overlapping diversity patterns. It is suggested that sesame maintenance breeding should be carried out in areas either with minimal natural out-crossing or with selfing in areas where forced self-seed set is possible.