越冬期低温对冬小麦叶片生理特性的影响

Effects of Low Temperature on Physiological Indexes in Leaves of Different Winter Wheat Varieties in Over-wintering Stage

为筛选能反映不同品种小麦应对低温响应的生理指标,以周麦18、周麦21、新麦208和偃展41104个品种为材料,研究越冬期低温对冬小麦叶片生理特性的影响。结果表明:随胁迫温度的降低,小麦叶片可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量呈先升后降变化趋势,其含量随温度变化曲线均可用三次函数方程进行拟合;叶片SOD活性呈先升后降变化趋势,叶片MDA含量持续上升,其含量随温度变化曲线可用二次函数方程进行拟合;叶片POD活性的动态变化表现出品种间差异,随温度的降低,周麦21叶片POD活性持续降低,而周麦18、新麦208和偃展4110则持续增加。在测定的6个生理指标中,脯氨酸含量和MDA含量在4个品种间变化趋势一致,可以作为反映越冬期冬小麦应对低温响应能力的抗性指标。

In order to select reasonable physiological indexes which could reflect the response capabili- ty to low temperature of different winter wheat varieties, 4 winter wheat varieties were chosen as experimental materials, including Zhoumai-18, Zhoumai-21, Xinmai-208 and Yanzhan-4110. In overwintering stage, the wheat plants were treated in laboratory with low temperature. And the effects of low temperature on physiological indexes in leaves were studied. The results showed that, the content of soluble sugar, soluble protein and free proline tended to rise at beginning and then declined as temperature fell down. The fitted equation of their variation tendency could be described as cubic function. With the stress temperature decreased, SOD activity increased and then decreased, while the content of MDA increased continuously. Meanwhile, the variation trend of SOD activity and MDA content with low temperature could be fitted with quadratic function. There was a variation on POD activity in leaves among the 4 varieties. As the temperature dropped, POD activity of Zhoumai-21 declined while Zhoumai-18, Xinmai-208 and Yanzhan-4110 ascended. Among the 6 indexes discussed in this paper, proline content these two indexes could be in overwintering stage. and MDA content showed the chosen as the indicators in low similar tendency among the 4 varieties. So, temperature-resistant identification of wheat in overwintering stage.