Abstract: Two winter wheat cultivars differing in the overwintering survival rate were used as the trial materials to investigate the effects of soil water contents on the freezing tolerant abilities of winter wheat during winter season. The gradient of the soil water contents was designed as follows: 15%±2%, 30%±2%, 45%±2% and control (CK, 35%~40%), which converted into soil relative water contents as 22.4%~29.3%, 48.3%~55.2%, 60.7%~69.1% and 74.1%~81.0%, respectively. And some physiological and biochemical traits were measured. The results showed that the malondialdehyde (MDA) contents and soluble protein contents increased with soil water content decreasing. And superoxide dismutase (SOD), catalase (POD) and glutathione (GSH) values rose under severe drought(15%±2%) treatment. The winter wheat cultivar with freezing tolerance has higher values in SOD, POD, GSH and AsA, as well as stronger ability for active oxygen removal than the cold sensitive one. The soil water content of 35.0%~ 40.0% before the soil frozen-up has more benefit to the overwintering survival of winter wheat.

Key words: Soil water content, Winter wheat, Physiological and biochemical characteristics

摘要： 为明确冬小麦越冬期间土壤水分对其抗寒性的影响，以返青率存在差异的两份冬小麦品种为试验材料，对其进行水分梯度试验，共设置土壤绝对含水量的15%±2%、30%±2%和45%±2%和对照（CK，35%~40%）4个水分处理，其土壤相对含水量分别为22.4%~29.3%、48.3%~55.2%、60.7%~69.1%和74.1%~81.0%，对一些与抗寒性相关的生理生化指标进行测定。结果表明，水分胁迫会引起丙二醛（MDA）和可溶性蛋白含量升高；重度干旱（15%±2%）会引起超氧化物歧化酶（SOD）、过氧化氢酶（POD）、谷胱甘肽（GSH）值升高。抗寒性强的品种其平均SOD、POD、GSH和AsA值高于抗寒性弱的品种，其活性氧清除能力强，封冻前土壤绝对含水量为35%~40%更有利于冬小麦的安全越冬。

关键词: 土壤含水量, 冬小麦, 生理生化特性