Characterization of Newly Identified Mung Bean [Vigna radiata (L.) Wilczek] Landraces for Yellow Mosaic Disease Resistance Using Morphological, Biochemical and Molecular Traits

Yellow mosaic virus (YMV) poses a major threat to mung bean cultivation by causing severe yield losses, making the development of resistant varieties crucial for stable production and food security. This study assessed 19 mung bean landraces under field and controlled environmental conditions. The DUS characterization of mung bean landraces confirmed their phenotypic distinctiveness, genetic uniformity, and stability across environments, while evaluation under YMV stress revealed significant variability in morphological and biochemical traits, with high-yielding landraces showing enhanced chlorophyll and phenol content. YMV response analysis identified 26% of the accessions as resistant and 21% as moderately resistant. Correlation analysis indicated a strong positive association between yield and phenol content (r = 0.943), a strong negative correlation with peroxidase activity (r = -0.932), and a moderate positive correlation with polyphenol oxidase (r = 0.705). Principal component analysis (PCA) indicated that the first three components explained 77.4% of variance. Molecular analysis showed polymorphism information content (PIC) values ranging from 0.32 to 0.89 with an average 0.67, indicating moderate to high polymorphism. Markers MAB128079 (0.89), MAB128135 (0.83), MB112A (0.75), and MBM-01589 (0.75) had high PIC values. Principal coordinate analysis (PCoA) grouped landraces by genetic makeup under YMV stress, with the first three axes explaining 62.1% of variation. Phylogenetic analysis supported these groupings, showing within-cluster similarity coefficients of 0.73-0.93, reflecting closer genetic relatedness within clusters than between them. The resistant landraces identified in this study hold potential as donors for breeding programs aimed at enhancing YMV resistance in mung bean crops.