脱驯化对寒地冬小麦抗寒性影响的探析

寒地冬小麦的安全越冬受制于 3个外界因素， 分别是低温驯化程度、 越冬期间温度、 以及返青期温度。为分析低温驯化对冬小麦抗寒性的影响， 笔者以抗寒性不同的 2个冬小麦品种为材料， 在其生长的低温驯化阶段分别对其进行脱驯化及低温处理， 测定不同处理下冬小麦植株的成活率及保护酶活性。研究结果得出， 10℃脱驯化处理 2天对植株造成的伤害较 20℃脱驯化 2天显著降低； 抗寒品种 ‘东农冬麦 1号’ 只有在 11月 10日发生 10℃脱驯化 2天其成活率显著降低， 而不抗寒品种在 10月 26日发生10℃脱驯化 2天其成活率为 50%； 20℃脱驯化 2天再-12℃ 3天处理， 抗寒品种在 10月 31日后其成活率低于 50%， 相同处理下不抗寒品种所有时期成活率均低于 50%。抗寒品种经历 20℃脱驯化 2 天后再经历-12℃ 1天低温植株的 SOD酶活性达到最高。由此得出， 低温驯化期发生脱驯化冬小麦植株的成活率降低。

Impact Analysis of De-acclimation on Cold Resistance of Winter Wheat in Frigid Region

There are three external factors limiting the safe wintering of winter wheat, which are the degree of cold-acclimation, the temperature of wintering period and the temperature of returning green stage. In order to understand the impact of cold-acclimation on cold resistance of winter wheat, 2 varieties with different cold resistance were used as materials, de-acclimation and low-temperature treatment were conducted in the lowtemperature acclimation stage, the plants survival rate and antioxidant enzymes activities were examined. The results showed that the injury degree of plant with two days of 10℃ de-acclimation treatment was significantly lower than that of 20℃. The survival rate of cold resistance variety (DM1) dropped significantly only with two days of 10℃ de-acclimation on November 10, while the survival rate of cold sensitive variety was 50% with two days of 10℃ de-acclimation on October 26. After October 31, the survival rate of cold resistance variety was less than 50% with two days of 20℃ de- acclimation and then three days of - 12℃ . Under the same treatment, the survival rate of cold- sensitive variety was less than 50% during all the stages. The highest activity of SOD enzyme in cold resistance variety was obtained with two days of 20℃ de-acclimation and then one day of - 12℃ . The survival rate of winter wheat was decreased by cold de- acclimation during coldacclimation period.