Effect of natural ageing on biochemical changes in relation to seed viability in okra(Abelmoschus esculentus)

Abstract

Effect of natural ageing on various storage enzymes, viz. peroxidase, catalase, superoxide dismutase (SOD), malondialdehyde (MDA) content and dehydrogenase activity (DHA) were studied during storage of seed in relation to seed viability and germination on three cultivars of okra, viz. ArkaAnamika, HisarUnnat and VarshaUphar. The present investigation revealed that the level of various enzymes have been studied so as to find the exact cause of seed deterioration. The activities of peroxidase, catalse, superoxide dismutase (SOD) and dehydrogenase activity (DHA) decreased whereas, malondialdehyde (MDA) content increased as the ageing period progressed in all the varieties. The cultivar VarshaUphar recorded higher activities of peroxidase, catalase, SOD and DHA and lower in MDA content among all the cultivars at the end of the storage period. In natural aged seed lot catalase and peroxidase activities decreased as the ageing progressed in all the three varieties, the rate of decreasing of both the enzymes activity was higher after 14 months of storage. Dehydrogenase activity was maximum up to 14 months of storage and after that it declined in terms of absorbance among all the varieties. It decreased at faster rate after 18 months of storage. During natural ageing no major changes in protein spectrum were recorded. No significant differences were observed in banding pattern of soluble proteins during ambient storage in all the three varieties. the germinability/viability of the seeds decreased as the ageing period progressed as a result of decreased in peroxidase, catalase, SOD and DHA activity and increased in MDA content in all the three varieties of okra.