Genetic diversity as assessed by ISSR markers in Blackgram (Vigna mungo (L.) Hepper)

An investigation was carried out on a collection of 23 blackgram genotypes involving 16 releasedvarieties, six pre release cultures and one wild species Vigna mungo var. silvestris to study the genetic diversityusing twelve ISSR primers. The number of alleles produced by different ISSR primers ranged from eight to 17with an average of 11.5 per primer and the level of polymorphism was found to be 82.05 percent. Similaritymeasures and clustering analyses were made using ISSR data. The resulting dendrogram distributed the 23blackgram genotypes into five main clusters. The highest genetic similarity coefficient was measured betweengenotypes CBG 671 and CBG 632. The results of PCoA were comparable to that of grouping based on UPGMAand 23 genotypes were grouped into four groups. Genotype Vigna mungo var. silvestris was placed separatelyfrom rest of the genotypes in both the analyses. Grouping of varieties using ISSR markers did not show anyrelevance to their pedigree. All the pre release cultures in one group revealed that only a portion of geneticvariation has been exploited. The results revealed that, genetic diversity is low among the varieties releasedfrom the respective institute and hence genotypes were grouped according to the research institutes from whichthey released. It suggests that the research institutes have to enlarge the genetic base for variety development.