Characterization of morpho-agronomic traits and powdery mildew resistance in mung bean (Vigna radiata)

Abstract

Background: Exploring genetic variation and screening for disease resistance is an important step in crop breeding initiatives but is lacking for many bean varieties including mung bean. The present study evaluated the diversity of 42 morpho-agronomic traits and screened mung bean genotypes for resistance to powdery mildew disease. A total of 132 mung bean and rice bean (R200) genotypes (as checks) were evaluated in an augmented incomplete block design across two cropping seasons. Pivot tables were used to analyse qualitative data, whereas the variation of 13 quantitative traits was examined using the generalized linear model (PROC GLM), agglomerative hierarchical clustering (AHC), and principal component analysis (PCA). Result: The genotypes displayed a wide variation for the majority of traits evaluated and significant differences were observed among genotypes, block effect, and between seasons. Similarly, the effects due to checks, genotypes, and genotypes and controls were significant. One mung bean (G32) genotype and one rice bean (R200) exhibited resistance to powdery mildew under field conditions. Principal component analysis revealed that the first four PCs explained 59.77% of the total variation among the genotypes studied. In addition, cluster analysis grouped all the genotypes into four major clusters. Conclusion: The trait variation recorded and resistance to powdery mildew disease provide valuable insight for developing breeding strategies especially with respect to reducing losses in mung bean and rice bean to powdery mildew.