PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Powdery mildew caused by Erysiphe polygoni is one of the main pathogens on mung bean that causes significant yield loss. This study determined the agronomic performance and physio-biochemical activities of twelve mung bean genotypes under powdery mildew infection. The experimental design was arranged in a completely randomized block design with three replicates. Initial disease symptoms appeared 14 days after planting (DAP) and then progressed to 31.7% in the moderate genotype (Sampeong) and 87.2% in the susceptible genotype (G2). The study suggested no significant correlation between chlorophyll contents and the severity of powdery mildew in mung bean genotypes; however, the disease negatively affected the yield in susceptible genotypes. Total phenolic and flavonoid contents in leaves showed a positive relationship with disease severity and mung bean resistance in the G6 genotype, in Vima 1. and Sampeong cultivars. Our findings showed that the phenolic compounds including phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) activities in the leaves were important factors for mung bean resistance to powdery mildew and this interaction impacted the growth and productivity of mung bean plants.