Antioxidant Response Of Brassica Plants In Protection Against Alternaria Brassicicola

In current study eleven Brassica genotypes, with diverse range of response to Alternaria black spot disease (ABSD), were evaluated to assess the role of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in disease resistance. Post-infectional POD and SOD activities increased the resistance in genotypes. Genotype BC9 accumulated highest POD and SOD activity, while lowest was observed in susceptible genotype BC1, which showed maximum ABSD incidence. The significant (p?0.01) negative correlation was found between pre- and post-infectional POD, SOD activities and percent disease index (%DI). In contrast, post-infectional CAT activity was lower than pre-infectional CAT activity except in genotype BC3. So, there was non-significant correlation between pre- and post-infection CAT activity and % DI. It can be proposed that CAT may have not significant role in disease resistance and it is predicted that such CAT activity is due to its enzyme inhibition by ABSD. Correlative evidence established the role of POD and SOD in black spot disease resistance in Brassica. The SOD and POD activities can be utilized as biochemical markers in screening of Brassica germplasm to differentiate resistant genotypes against ABSD.