Assessment of Genetic Diversity for Cercospora Leaf Spot (CLS) Resistance in Mung Bean [Vigna radiata (L.) Wilczek] using SSR Markers

Abstract

Background: CLS causes severe yield loss in mung bean. To sustain mung bean health, it is vital to include alleles that may be useful in resisting CLS. Therefore, in the present study, 90 mung bean genotypes were included for assessing genetic diversity using 66 SSR markers for CLS resistance. Methods: The mung bean crop was regularly monitored for the presence of pathogen and development of CLS disease in natural field conditions during pre rabi 2018 and pre rabi 2019. CLS screening assessments of germplasms were carried out using a 1-5 rating scale. Total genomic DNA was isolated from the leaf samples of all the genotypes and SSR genotyping was performed. The genotyping data were analysed by using GenAlEx 6.51b2 and TASSEL 5.0 software programme for genetic diversity parameters. Result: A moderate molecular diversity was observed in the panel population as a wide variation in alleles showed a range of 80 bp to 300 bp with the average PIC value of 0.40. The maximum percentage of polymorphic loci was 75.76% in the resistance genotypes followed by 56.06% in moderately resistant genotypes. The percentages of Shannon information among and within the population were found to be 44% and 56%, respectively. The archaeopterx tree differentiated the panel population into two major clusters, i.e., cluster I and cluster II, which were again sub divided into different sub-clusters and sub-sub clusters. These findings indicate that, the mung bean germplasm panel used in the present study could enrich the local gene pool and provide information for CLS resistance breeding.