Studies on antioxidants and peroxidase isoenzymes in seedlings of twelve cultivars with four different durations of flowering time in pigeon pea (Cajanus cajan (L.) Millspaugh)

Objective: The present study is an attempt to understand the role of enzymatic and non-enzymatic an- tioxidants as well as peroxidase isoenzymes in order to differentiate the four flowering durations of pigeon pea cultivars. Methods: The assay of superoxide dismutase, catalase, peroxidase, ascorbate oxidase, ascorbic acid, reduced glutathione, lipid peroxidation, protein and phenolic content was done for the evaluation of antioxidant activity. For peroxidase isozymes assay, native-PAGE was carried out with 10% acrylamide gels at 4 �C without SDS and b-mercaptoethanol. Results: Among all the cultivars ICP 15599, which is an extra-early flowering variety showed highest levels of both enzymatic and non-enzymatic antioxidants and least lipid peroxidation. Isoenzyme marker analysis of POD showed six common isoforms in all the 12 varieties and an additional isoform in ICP 15599. Conclusion: Among four different flowering durations extra-early group showed highest activity of enzymatic and non-enzymatic antioxidants, whereas lipid peroxidation was least. The peroxidase isozyme analysis showed there is no specific isoform for flowering time identification, but however there is one marker for extra-early cultivar (ICP 15599).