Abstract:

In order to find the relationship between chilling sensitivity and activities of antioxidant enzymes of postharvest tomato fruits, two cultivars of postharvest tomato fruits, Santiam (Solanum lycopersicum L. cv. Santiam) and Lichun (Solanum lycopersicum L. cv. Lichun), were treated with short-time (24 h) or long-time (20 d) chilling stress, and the changes in activities of antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) during chilling stress were measured. It was found that chilling tolerance of tomato cultivars could be indicated obviously by activities of the four enzymes, and a positive relationship was observed between them. Activities of CAT, POD and SOD could distinctively reflect chilling tolerance diversity (p < 0.05) between the two cultivars within 4－24 h under chilling stress. Conclusively, cold tolerance of postharvest tomato fruits can be fast and effectively judged from activities of the antioxidant enzymes.

Key words: antioxidant enzyme, chilling injury, cold tolerance, oxidative stress, tomato fruit