Assessment of genetic diversity in black gram [Vigna mungo (L.) Hepper] genotypes based on ISSR

A study was carried out among 22 black gram genotypes to study the genetic diversity using 20 ISSR primers. Screening of the primers revealed that only 15 out of the 20 primers produced amplification. A total of 84 amplified bands were obtained, out of which 72 were polymorphic 85.71 percent polymorphism. The total number of amplified bands varied between 1 (UBC-813 and UBC-878) and 9 (UBC-826) with an average of 5 bands per primer. The overall size of PCR amplified products ranged between 250 bp to 2000 bp. PIC values ranged from 0.00 to 0.51 with an average of 0.285 across all genotypes. Five unique bands were detected in four genotypes, out of which the genotype U-9 gave maximum number of distinct bands. The size of these unique bands ranged from 450 bp to 2000 bp. Based on the UPGMA derived dendrogram and PCA, the 22 genotypes could be divided into four main clusters. While Cluster I included 16 genotypes, the Clusters II, III and IV included two genotypes each. Genotypes IC-16511 and UTTARA, UH-177 and IPU2K-21, STY-2834 and UH-177 were found to be genetically distant from each other with a minimum similarity value of 0.42. The results are encouraging with the suggestion that the ISSR marker could prove to be a versatile tool in further screening of the Vigna germplasm pool for study of genetic divergence and the establishment of phylogenetic relationship amongst accessions.