Vol. 12, Issue 2 (2023)

An experiment was conducted to study the different biochemical constituents imparting resistance and susceptibility to rust of sorghum disease caused by Puccinia purpurea Cooke. For this, five rust resistant (R) and five rust susceptible (S) genotypes of sorghum were inoculated at 30 days after sowing (DAS) and studied at both 30 days after inoculation (DAI). Reduction in the chlorophyll a, chlorophyll b, total chlorophyll, soluble protein, reducing sugar, non reducing sugar, total sugar and phenol contents was found in inoculated S genotypes as compared with inoculated R genotypes. The total phenol content and enzymatic activities viz., peroxidase and polyphenol oxidase were decreased in R as well as S genotypes when challenged with sorghum rust, while increased levels of phenol, peroxidase and polyphenol oxidase activity were found more in R genotypes than S genotypes.