Changes in seedling vigour and biochemical composition of soybean seeds under ambient temperature and refrigerated conditions of storage

Germination percentage, seedling vigour, total soluble sugars and starch, protein content, lipid composition, lipid peroxidation and activities of antioxidant enzymes were determined in soybean seeds at initial as well as after 90 and 180 days of storage (DOS). High germination percentage and vigour index was maintained for 180 days in seeds stored at refrigerated temperature. Total soluble sugars, reducing sugars and sucrose content decreased while that of starch increased at 180 DOS. There was a slight decrease in the oil content of the seeds stored in refrigerated or ambient conditions with marginal change in glycolipids, sterols, triglycerides and free fatty acid content during storage. Ageing enhanced lipid peroxidation and inhibited the activities of catalase and peroxidase. The increase in lipid peroxidation was lower in seeds stored in refrigerated conditions with corresponding decrease in the activities of catalase and peroxidase after 90 DOS. Based on the parameters recorded, the seeds stored in refrigerated conditions were found to be more vigorous than those at ambient temperature.