麦秸翻压还田对隔茬冬小麦旗叶抗性的生理效应

Physiological effects of ploughing wheat straw under soil on flag-leaf resistance of winter wheat under wheat-summer corn rotation

为了揭示秸秆翻压还田对冬小麦旗叶叶片衰老及抗性指标的变化规律,试验设置4个小麦秸秆翻压还田量(0、4500、6000、7500kg/hm2),测定分析了冬小麦旗叶叶绿素含量、光合速率、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性及可溶性蛋白质含量等抗性指标。结果表明,秸秆还田可明显减缓冬小麦植株衰老过程中叶片叶绿素的降解和光合速率下降,并有效调节叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)活性下降、可溶性蛋白质含量下降和丙二醛(MDA)含量的增加,延缓了冬小麦生育后期叶片的衰老;通过对各抗性指标与光合速率的相关性分析表明,各抗性指标在抑制冬小麦衰老过程中的作用大小依次为:丙二醛>可溶性蛋白质>POD活性>SOD的活性(丙二醛-0.999**;可溶性蛋白质0.997**;POD活性0.976*;SOD活性0.954*)。综合各处理的抗性指标得出,处理Ⅲ(6000kg/hm2)在提高作物后期抗逆性能力方面表现较好,处理Ⅳ(7500kg/hm2)表现较差。

To study the physiological effects of ploughing wheat straw under soil on the senescence and resistant parameters of the flag leaves of winter wheat under wheat-summer corn rotation, the experiment investigated the chlorophyll contents, photosynthetic rates, MDA contents, SOD and POD activities and solvable protein contents in the flag leaves of Winter indicated that ploughing wheat straw under soil could remarkably slow down the declines in the chlorophyll contents and photosynthetic rates, inhibit the reductions in the SOD and POD activities and the increases in the MDA contents in the leaves of wheat plants during senescence so as to delay leaf senescence of wheat during late growth; the correlations of different resistant parameters with the photosynthetic rates indicated that during the senescence of winter wheat, the antiaging contribution of different resistant parameters increased in the order of MDA content 〉 solvable protein content 〉 POD activity 〉 SOD activity（ with correlation coefficients standing at - 0.999 ; 0.997, 0.976 and 0.954, respectively）. Among all treatments, ploughing wheat straw under soil had the most favorable effect at the rate of 6000 kg wheat straw / hm2 and the least favorable effect at the rate of 7500 kg wheat straw/hm2.