限水条件下灌水量对强筋小麦旗叶衰老特性和籽粒产量的影响

Influence of Irrigation Amount under Water Restriction on Flag Leaf Senescence Characteristics and Grain Yield of Strong-Gluten Wheat

为探究灌水量对强筋小麦花后旗叶衰老和籽粒产量的调控效应,以2个强筋小麦品种(中麦998和中麦1062)为供试材料,设置0 m^(3)·hm^(-2)(W_(0))、450 m^(3)·hm^(-2)(W_(1))和900 m^(3)·hm^(-2)(W_(2))3个灌水量(拔节期和开花期各灌水50%),分析了不同处理下小麦旗叶叶绿素含量、同化物含量、丙二醛含量、抗氧化酶活性、抗衰老激素含量、蛋白质含量和籽粒产量的差异。结果表明,增加灌水量可延缓强筋小麦花后旗叶衰老。灌浆前中期旗叶叶绿素含量在不同处理间无显著差异,灌浆后期叶绿素含量在W_(2)处理下最高。W_(2)处理下小麦旗叶可溶性糖含量显著高于其他处理;旗叶可溶性蛋白含量在花后0~21 d保持较高水平,在花后21~35 d含量逐渐下降,且W_(1)处理下花后21~35 d旗叶可溶性蛋白含量较W_(0)处理显著提高。灌水量对花后0~21 d强筋小麦旗叶中游离氨基酸含量无显著影响,而在灌浆后期以W_(2)处理最高;与W_(0)处理相比,增加灌水量可显著提高旗叶过氧化氢酶活性、过氧化物酶活性和生长素含量,显著降低丙二醛和脱落酸含量,并且显著延长测定酶活性和激素含量峰值出现时间。随灌水量的增加,籽粒蛋白质含量下降,但产量显著升高。总体来看,在本试验条件下,W_(2)处理(拔节水450 m^(3)·hm^(-2)+开花水450 m^(3)·hm^(-2))能够显著延缓强筋小麦旗叶衰老,在维持较高蛋白质含量同时,获得最高籽粒产量。

In order to investigate the effect of irrigation amount on post-flowering flag leaf senescence and grain yield of strong-gluten wheat,two varieties of strong-gluten wheat(Zhongmai 998 and Zhongmai 1062)were used in this study.Three irrigation amounts of 0 m^(3)·hm^(-2)(W_(0)),450 m^(3)·hm^(-2)(W_(1))and 900 m^(3)·hm^(-2)(W_(2))were set up(50%irrigation individually at jointing and flowering stages),and the chlorophyll content,assimilate content,malondialdehyde content,antioxidant enzyme activity of wheat flag leaves,and changes in anti-aging hormone content,protein content,and grain yield were analyzed under different treatments.The results showed that increasing irrigation amount could delay the flag leaf senescence of strong-gluten wheat after flowering.There was no significant difference in the chlorophyll content of flag leaves among different treatments before and at the middle stage of grain filling,while the chlorophyll content was highest under the W_(2)treatment at the later stage of grain filling.The soluble sugar content of wheat flag leaves under W_(2)treatment was significantly higher than that of other treatments.The soluble protein content of flag leaves remained at a high level from 0~21 d after flowering,and gradually decreased from 21~35 d after flowering.W_(1)treatment significantly increased the soluble protein content of flag leaves from 21~35 d after flowering compared to W_(0)treatment.The amount of irrigation had no significant effect on the content of free amino acids in flag leaves of strong-gluten wheat during 0~21 d after flowering,while W_(2)treatment had the highest content at the late filling stage.Compared with the W_(0)treatment,increasing irrigation amount could significantly increase the catalase activity,peroxidase activity,and auxin content of flag leaves;significantly reduce the content of malondialdehyde and abscisic acid,and significantly prolonged the peak time for measuring enzyme activity and hormone content.With the increase of irrigation amount,the protein content in grains decreased,but the yield significantly increased.Overall,under the conditions of this experiment,W_(2)treatment(irrigation at jointing 450 m^(3)·hm^(-2)+irrigation at flowering 450 m^(3)·hm^(-2))can significantly delay flag leaf senescence,maintain high protein content,and achieve the highest grain yield.