34℃ 1—5天的热锻炼提高了小麦叶片的膜稳定性、超氧物歧化酶(SOD)和过氧化氢酶(CAT)的活性,耐热品种提高程度大大高于热敏感品种。同时热锻炼降低了小麦叶片的可溶性蛋白含量但提高了蛋白质的稳定性。34℃热锻炼后小麦叶片在50℃高温伤害处理过程中,耐热品种比热敏感品种保持有较高的SOD酶活性和较低的膜伤害(即高的膜稳定性)。可以认为,高温引起膜伤害是一个自由基伤害的过程,而SOD酶、CAT酶活性提高对膜的稳定性提高起了一定作用。 Heat treatment at 34 ℃ for 1-5 days increased membrane stability, superoxide dismutase (SOD) and catalase (CAT) activities of wheat leaves, and the increase of heat-tolerant cultivars was significantly higher than that of heat-sensitive cultivars. At the same time, hot exercise reduced the soluble protein content of wheat leaves but increased the protein stability. During heat injury at 34 ℃, the heat-tolerant cultivars maintained higher SOD activity and lower membrane injury (ie, higher membrane stability) than the heat-sensitive cultivars at 34 ℃. It can be considered that high temperature caused membrane injury is a free radical injury process, and SOD enzyme, CAT enzyme activity increased membrane stability played a role in improving.