Biochemical Transformation in Brassica spp. due to Peronospora parasitica infection

Different healthy and infected plant parts i.e. cotyledon, leaf and inflorescence of three Brassica spp. i.e. B. juncea cv Varona (susceptible), B. carinata He 9–1 (moderately resistant) and B. napus NDBN-l (Resistant) infected with Peronospora parasitica were analysed for various biochemical parameters viz. nitrate reductase activity, chlorophyll, sugar, total protein, total phenol, total minerals and total free amino-acids content to observe the biochemical transformation in the infected plant parts of Brassica spp. It was observed that nitrate reductase activity, chlorophyll content, total sugar, total protein and total phenol content were decreased in all the infected plant parts of three Brassica spp. However, only chlorophyll content in inflorescence and total free amino acid content were increased in the infected plant parts of three Brassica species. Total minerals content did not differ in healthy and infected plant parts of three Brassica species. Increased and decreased pattern in biochemical parameters of the infected plant parts was maximum in susceptible followed by moderately resistant and resistant. The resistant species of Brassica showed little changes in the biochemical parameters due to infection.