氮、硫肥与灌浆后期高温胁迫对小麦籽粒产量和品质的影响

灌浆期高温胁迫通常导致小麦籽粒产量降低、品质变差.为了探索有效缓解高温胁迫不利影响的有效措施,在大田条件下,以济麦20为试验材料,运用后期高温棚增温的方法,研究了氮、硫肥与灌浆后期高温对小麦籽粒产量和品质的影响.结果表明:高温处理后小麦千粒质量、籽粒产量显著降低(19.7%～28.3%),蛋白质含量升高,蛋白质组分中不溶性谷蛋白含量下降,可溶性谷蛋白含量上升,面团形成时间和稳定时间缩短;氮肥追施比例由50%增加到70%,非高温处理的籽粒产量无显著变化,不溶性谷蛋白质含量和谷蛋白聚合指数(不溶性谷蛋白含量/可溶性谷蛋白含量)升高,面团形成时间和稳定时间延长;高温处理的千粒质量和籽粒产量因氮肥追施比例提高而提高(2.07%～3.58%),面团形成时间和稳定时间缩短;不论高温处理还是非高温处理,与追施硫肥相比,硫肥基施提高籽粒产量、谷蛋白聚合指数,延长面团形成时间和稳定时间;为了有效缓解灌浆后期高温对小麦籽粒产量和品质的不利影响,硫肥基施、氮肥施用基追比50%:50%是较为适宜的施肥模式.

Effects of high temperature stress at late grain-filling stage and nitrogen and sulfur fertilization on wheat grain yield and quality

High temperature stress at grain-filling stage often leads to reduced wheat grain yield and worsened grain quality.In order to find out effective measures to mitigate these adverse effects,a field trial with wheat variety Jimai 20 was conducted.High temperature stress at late grain-filling stage was created by plastic tunnel,and nitrogen and sulfur fertilizers were applied as basal and topdressing.The results showed that under high temperature stress,the grain yield and 1000-grain mass decreased significantly(from 19.7% to 28.3%),protein content increased,insoluble glutenin decreased while soluble glutenin increased,and the time for dough development and stabilization shortened.In the control(without high temperature stress),increasing nitrogen topdressing rate from 50% to 70% led to no significant change in grain yield but higher content of insoluble glutenin,higher polymerization index of glutenin(ratio of insoluble glutenin to soluble glutenin)and longer time for dough development and stabilization;while under high temperature stress,higher nitrogen topdressing rate resulted in a 2.07%-3.58% increase of grain yield and 1000-grain mass,and a shortened dough development and stabilization time.Compared with topdressing S,basal application of S increased the grain yield and glutenin polymerization index,and prolonged the dough development and stabilization time,whether high temperature stress existed or not.It was suggested that to mitigate the adverse effects of high temperature stress at late grain-filling stage on wheat grain yield and its quality,an appropriate fertilization mode could be a basal application of S fertilizer plus half basal applying and half topdressing N fertilizer.