Antioxidative Enzyme Responses against Fusarium wilt (Fusarium oxysporum f. sp. ciceris) in Chickpea Genotypes

Three wilt resistant chickpea genotypes viz., JG 24, BCP-2010-1 and GJG 0919 confirmed by field screening and also by activity profile of defense related enzymes were screened in normal and wilt sick soil for antioxidative enzymes at pre and post infection stages along with four wilt resistant and three wilt susceptible checks. The evaluation of antioxidative enzyme profile in normal and wilt sick soil of these chickpea genotypes exhibited a differential response. The activity of three antioxidative enzymes viz., APX (ascorbate peroxidase), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) increased significantly in wilt susceptible checks viz., JG 62, Vikas and at post infection stage. The non compatible interaction between wilt resistant genotype and pathogen demonstrated lesser increase. At preinfection stage mean APX activity did not vary significantly from normal soil to wilt sick soil, however significant increase was observed at post infection stage with 1.08 µmoles ascorbate oxidized mg-1 protein min-1 in normal soil to 1.75 µmoles ascorbate oxidized mg-1 protein min-1 in wilt sick soil. At the post infection stage the root APX activity increased significantly in wilt susceptible group of genotypes from 2.07 to 2.38 µmoles ascorbate oxidized mg-1 protein min-1 with mean percent increase of 97.94%. Though APX activity increased at post infection stage in wilt sick soil in the wilt resistant genotypes percent increase was from 33.03 to 57.64 with a mean percent increase of 40.4%. Same trend was recorded in GPX and SOD activity.