Morpho-biochemical and molecular characterization of new mung bean [Vigna radiata (L.) Wilczek] landraces for Cercospora leaf spot (CLS) disease resistance

Abstract

Mung bean production is significantly lowered by Cercospora leaf spot (CLS) in various parts of the globe. The most effective way to increase mung bean resilience to this stress is to identify new CLS resistance sources. Therefore, a panel population of 13 landraces along with 2 susceptible check cultivar, and 11 SSR markers were taken for the present experiment. Correlation analysis suggested significant relationships between the quantitative traits, retained resistance (Banapur local, and Kalampur local), and moderately resistance (Dikhitapada local, and Fakirpur local 1) to CLS. However, total chlorophyll content (TCL) showed strong positive correlations with phenolic content (PHE) (0.984), peroxidase activity (POX) (0.931), and polyphenol oxidase activity (PPO) (0.969). Moreover, PHE (−0.769) and POX (−0.867) were also found negatively correlated with CLS disease reaction. The eigenvalues from the principal component analysis (PCA) indicated the first three principal components collectively explained 84.88 % of the total variance. Molecular analysis of the panel population suggested a PIC value range from 0.30 to 0.88, with an average 0.696, and markers such as cp01713 (0.84), cp02181 (0.87), and CEDG147 (0.88) had higher PIC values. Principal coordinate analysis (PCoA) suggested capturing of 69.06 % of the total variance by the first three axes, and the landraces were categorizing into three clusters (cluster A, B and C). The genetic distances among the landraces ranged from 0 to 0.608, and phylogenetic tree differentiated them into three major clusters at respective Jaccard's similarity coefficient i.e., Cluster I (0.68), II (0.75) and III (0.83). Meanwhile, the resistance and moderately resistance landraces were observed in cluster A and cluster B, and in cluster II and cluster III respectively. The resistance landraces obtained from the present study could be used as potential donor for breeding process towards CLS resistance in mung bean.