Vol. 11, Issue 11 (2022)

Author(s):
Suryakanth, Venkatesh, NS Pankaja, J Mahadeva, Umashankar and Milan Gowda

Abstract:
The cowpea genotypes showing immune, resistant, moderately resistant, moderately susceptible, susceptible and highly susceptible reaction to the rust pathogen (Uromyces phaseoli var. vignae (Barcl.) Arth.) were used to study the biochemical variations due to its infection. Various biochemical parameters viz., total phenols, total sugars, protein content, total chlorophyll, peroxidase, phenylalanine ammonia lyase and β1, 3-glucanase activity were assessed. The results revealed that the amount of these biochemical components were significantly higher in leaves of diseased and healthy plants of resistant genotypes compared to other genotypes. However, excepting total sugars and total chlorophyll content all the other parameters were high in infected genotypes compared to healthy genotypes. Further, among the resistant genotypes the total phenols, total sugars, proteins, total chlorophyll, peroxidase, PAL and β 1, 3-glucanse content was highest in the resistant genotypes viz., EC-17058-1-1 (6.341 mg/g of fresh wt.), MFC-08-14 (3.887 mg/g of fresh wt.), MFC-08-14 (5.547mg/g of fresh wt.), KBC-2(1.733 mg/g of fresh weight),MFC-08-14(1.379 Absmin-1g^-1), EC-17058-1-1 (152 µmol of trans cinnamic acid min-1 g-1) and EC-17058-1-1 (31 µg of glucanase released g-1 fresh wt.) respectively. Whereas, least amount of these components was recorded in highly susceptible genotype C-152. Correlation study showed that all the biochemical parameters viz., total phenols, proteins, total sugars, total chlorophyll content, peroxidase, PAL and β 1, 3- glucanase enzyme activities were negatively correlated with disease severity of cowpea rust.