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