Temperature stress caused cucumber membrane lipid peroxidation. After treatment of chilling or heat,malondialdehyde (MDA) contents and production rates of superoxide anion radicals (O -· 2) in the leaves increased.And those were negative correlation with resistance to the stress.Both ascorbic acid (AsA) content and activities of \{peroxidase\} (POD) and catalase (CAT) decreased after 2 days treatment.Superoxide dismutase (SOD) activities of lines with high resistance to chilling increased after chill...