穗期高温对玉米子粒灌浆生理及产量的影响

为揭示玉米穗期高温胁迫对子粒灌浆生理及产量的影响,以耐热型玉米品种郑单958和热敏感型玉米品种先玉335为试验材料,研究了第9片叶完全展开至抽雄期高温对玉米子粒灌浆特性、淀粉合成酶活性、激素含量和产量的影响。结果表明,穗期高温处理,郑单958和先玉335的产量分别比对照降低了11.14%和25.40%;2个品种的粒重和灌浆前期的灌浆速率降低,到达最大灌浆速率的时间延迟,灌浆速率最大时的生长量减小,活跃灌浆期延长;灌浆前期子粒淀粉合成酶活性降低;高温对先玉335的影响明显高于对郑单958。高温处理后,2个品种子粒中的生长素、玉米素核苷和赤霉素含量变化趋势一致,均表现为灌浆初期降低,灌浆后期升高,脱落酸含量表现则相反。

The Effects of High Temperature at Spike Stage on Grain-Filling Physiology and Yield of Maize

To reveal the effects of high temperature stress at spike stage on grain-filling physiology and yield of maize, the temperature non-sensitive variety Zhengdan 958 and temperature sensitive variety Xianyu 335 were used as the experimental materials in this study. The results showed that the grain yields of Zhengdan 958 and Xianyu 335 decreased by 11.14% and 25.40%, respectively, compared with the control under high temperature at spike stage. High temperature treatment reduced the grain weight and the grain-filling rate at the early filling stage, delayed the time to reach the maximum filling rate, reduced growth of the maximum filling rate, increased the active filling period and reduced starch synthase activity at the early grain-filling stage of two maize varieties. The effects of high temperature treatment on Xianyu 335 was significantly higher than that of Zhengdan 958. The contents of auxin (IAA), zeatin riboside (ZR) and gibberellin (GA) in two maize varieties showed the same trend after high temperature treatment, which showed that the contents of IAA, ZR and GA decreased at the early filling stage and increased at the late filling stage, while the abscisic acid content followed the opposite trend.