Cross Species Amplification of Cowpea Derived Unigene-SSR Markers and Diversity Analysis in Black Gram [Vigna mungo (L.) Hepper]

Black gram [Vigna mungo (L.) Hepper] is an important legume crop in Asia, where it is a major source of dietary protein for its predominantly vegetarian population. Molecular breeding programme in this crop has made little progress due to lack of genomic resources. It largely depends on the sequence information available in the closely related taxa. Ninety-six cowpea derived unigene-SSR markers were tested for their cross species amplification in black gram. Forty-nine unigene-SSR primers showed cross species amplification and diversity among 42 black gram accessions were studied. Each unigene-SSR marker detected two to five alleles and 49 SSR primers collectively amplified 119 alleles in black gram with an average of 2.4 alleles/locus. The polymorphic information content (PIC) of the unigene-SSR markers ranged from 0.05 to 0.72 with an average of 0.41. Cluster analysis based on neighbor-joining method grouped the 42 accessions into three major clusters. The genetic closeness among the cultivars can be explained by the high degree of commonness in their pedigree. These unigene-SSR markers were also successful in detecting variation among 15 gamma ray induced mutants of black gram included in the present investigation. Functional categorization of these unigene-SSR markers corresponded to many genes with biological, cellular and molecular functions, and hence offers an opportunity to investigate the consequences of SSR polymorphism on gene functions and serves as valuable resource for black gram genetic analysis.