Effect of ascorbic acid on germination and activities of antioxidant enzymes of deteriorated safflower Goldasht cultivar seeds

In order to study the effect of ascorbic acid on germination and some physiologic characteristics of aged safflower an experiment was conducted as factorial arrangement in completely randomized design with three replications. Non-aged and aged (40 °C for 4, 6, 8 and 10 d) seeds of safflower were subjected to priming with ascorbic acid at concentrations of 0, 0.28 and 0.56 mM. In this research germination percentage and rate, seedling vigour, shoot and root length, shoot and root dry weight, malondialdehyde, catalase activity, superoxide dismutase activity and protein content measured. The results showed that germination and seedling growth decreased with aging increment. In all levels of aging, germination percentage and rate, shoot and root length, shoot and root dry weight increased at 0.28 mM ascorbic acid than other concentrations. Accelerated aging not only resulted in increased malondialdehyde, but also in decreased catalase activity, superoxide dismutase activity and protein content. Priming with 0.28 mM ascorbic acid decreased malondialdehyde after 12 hours imbibition, whereas increased catalase activity, superoxide dismutase activity and protein content under aging. The results suggest that aged safflower seeds priming with 0.28 mM ascorbic acid improves the germination and seedling growth by reducing membrane peroxidation and increasing the activities of catalase and superoxide dismutase enzymes after 12 hours imbibition.