Evaluation of Genetic Diversity in Indian Mustard (Brassica juncea var. rugosa) Employing SSR Molecular Markers

Indian mustard (Brassica juncea var. rugosa) constitutes an authoritative group of mustard crops in India. Evaluation of genetic diversity is a vivacious component of mustard breeding programmes for efficient utilization of plant genetic resources. In present study, 77 microsatellite markers were employed to assess the genetic diversity of 75 Indian mustard genotypes. Results revealed positive amplification for all SSRs, with 21 SSRs exhibiting polymorphic amplicons. A total of 99 alleles, ranging from 3 to 5 with an average of 4.71 alleles per SSR marker were obtained. The major allele frequency varied between 0.26 (cnu/m616) and 0.56 (ENA28F) with an average value of 0.36. The average polymorphic information content (PIC) value was 0.67 and ranged between 0.43 (ENA28F) and 0.76 (gi258660710gbGT071338.1). Mean value of 0.72 was detected for each pair of SSR primers, with the gene diversity per locus ranging between 0.53 (ENA28F) and 0.79 (gi258660710gbGT071338.1). The dendrogram grouped the 75 genotypes into three main clusters or subpopulations based on Unweighted Neighbour-Joining technique. The study revealed better understanding of the genetic diversity among different Indian mustard genotypes using genomic-SSR markers that could be exploited for the genetic improvement of the crop.