Post-infectional phenolic changes in maize due to Rhizoctonia solani f. sp. sasakii causing banded leaf and sheath blight

A basic study was undertaken to find out the possible role of the phenolics involved in resistance against banded leaf and sheath blight of maize. The phenolic content in all cultivars of maize increased after infection. This increase was more pronounced in resistant cultivars as compared to susceptible cultivars. The highest increase (32.14%) in accumulation of phenolics was noticed in diseased leaves of genotype BVM-4 infected with the Rf isolate. Accumulation of total phenol in diseased leaves of 10 genotypes against 5 isolates of R. solani varied from 119.67 to 160.33 μg/g fresh weight and in healthy leaves 111.66-124.33 μg/g fresh weight. Further analysis of the data revealed that the disease severity was negatively correlated with the accumulation of phenol having coefficient of correlation r = -0.83.