Effect of low temperature stress on some physiological and biochemical characteristics of Chinese cabbage in field

Under low temperature stress, the contents of osmosis adjustment matter (OAM), malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), perｏoxidase (POD),catalase (CAT) enzymes in Chinese cabbage leaves were determined. The results show that the contents of OAM, such as the soluble protein, soluble sugar, free proline increase with the temperature decreasing, but the activities of SOD, POD and CAT increase at first and then decrease. The contents of OAM among different Chinese cabbage cultivars are different.The contents of OAM of “Qiuzhenbai No. 16” and “Chundawang" are higher than those of others, which shows they have strong resistance to low temperature. Higher OAM content and higher activities of SOD, POD, and CAT are the intrinsically physiological and biochemical characteristics of Chinese cabbage to resist low temperature.