灌浆期增温对小麦籽粒结实及品质的双向效应及与施氮量的关系

Pros and Cons Effect of Warming on Wheat Grain Yield and Quality during Grain Filling

为了解长江流域小麦灌浆期的"高温逼熟"效应,采用新近发明的田间可移动式增温设施,在大田条件下于开花后对小麦进行了连续21d的"偏高"温度处理(冠层平均增温5.6℃),并调查高温胁迫下小麦籽粒结实和品质的变化及与氮素营养的关系。结果表明,高温胁迫后,在施氮0、135、180和225kg·hm-2条件下,小麦穗粒数较对照(自然温度)分别减少-6.0%、10.7%、11.3%、11.6%,千粒重分别下降15.7%、18.9%、23.5%、15.7%;籽粒蛋白质含量分别增加了22.4%、27.5%、28.3%、19.6%,湿面筋含量和沉降值分别提高了14.6%、17.1%、17.7%、18.1%和23.4%、17.5%、29.0%、21.8%,面团的形成时间和稳定时间分别延长了12.1%、259.5%、398.2%、322.6%和172.2%、232.5%、220.1%、72.2%。高温与施氮的互作效应只在蛋白质含量、吸水率、面团形成时间和稳定时间上达到显著或极显著水平,适量施氮会增强高温对蛋白质含量、面团形成时间和稳定时间的提高作用,减弱高温对吸水率的降低效应。可见,开花后连续高温对小麦籽粒结实和粒重产生负面影响,但对品质具有一定的改善效应。

In order to verify the＂heat-forced maturity＂of wheat during the grain filling stage in Yangtze River valley,the materials were continuously treated at 21days＇ ＂moderate-high temperature＂by the movable heating facility after anthesis in the field.Field components,quality of wheat and their relationship with nitrogen fertilizer under high temperature were investigated.Compared to the control,the grain number per spike and thousand kernel weight of the high treatments decreased by-6.0%,10.7%,11.3%,11.6% and 15.7%,18.9%,23.5%,15.7% under the nitrogen application amaunts of0,135,180 and 225kg·hm-2,respectively,and the protein content increased by 22.4%,27.5%,28.3% and 19.6%,respectively.Moreover,the content of wet gluten and sedimentation value increased by 14.6%,17.1%,17.7%,18.1% and 23.4%,17.5%,29.0%,21.8%,respectively,and ex-tended dough development and stability time increased by 12.1%,259.5%,398.2%,322.6% and172.2%,232.5%,220.1%,72.2%,respectively.The high temperature and nitrogen fertilizer application had significant effects on protein content,water absorption and dough development and stability time.Proper amount of nitrogen fertilizer enlarged the effects of high temperature on protein content and dough development and stability time,yet decreased the effects of high temperature on water absorption.It can be concluded that continuously high temperature after anthesis has negative effects on grain development and grain weight,but has positive effects on wheat quality.