Vegetos

Abstract

Molecular assessment of genetic diversity was done for 23 mungbean (Vigna radiata (L.) Wilczek) genotypes using ISSR marker system. Twenty ISSR primers were used in the study out of which thirteen primers enabled DNA amplification in all genotypes. A total of 75 amplified and reproducible amplicons were obtained from 13 primers, out of which 60 were found polymorphic. The total number of amplified bands varied between 2 (UBC-813) and 11 (UBC-810) with an average of 6.5 per primer. The overall size of PCR amplified products ranged between 200 to 2500 bp. PIC values ranged from 0.07 to 0.35 with an average value of 0.208 across all genotypes. Four unique bands were detected in four genotypes with 3 (UBC-818, UBC-820 and UBC-826) out of 13 ISSR primers. The genotype IC-393407 gave maximum number of distinct bands. The similarity indices between the 23 genotypes ranged from 0.38 to 0.94. The extent of diversity among genotypes was also estimated in relation to their source and a set of genotypes with narrow genetic bases developed from various region were identified. Based on a dendrogram generated through UPGMA method and PCA, most of the genotypes could be divided into two main clusters. Cluster I included twenty genotypes, while cluster II included three genotypes. The genotype GM-9925 lay apart from all the two clusters. A minimum similarity co-efficient of 0.38 was observed between genotypes GM-9925 and EC-398885 thereby indicating maximum genetic divergence. The Mantel statistical analysis (r = 0.92) also supported cluster analysis.