施氮量对小麦旗叶光合速率和光化学效率、籽粒产量与蛋白质含量的影响

Effect of Nitrogen Fertilizer Rate on Photosynthetic Rate and Photochemical Efficiency of Flag Leaf,Grain Yield and Protein Content of Winter Wheat

为给小麦高产高效栽培提供依据，在大田高产条件下，研究了施氮量对开花后小麦旗叶光合速率和光化学效率、旗叶和籽粒蔗糖含量及籽粒产量和蛋白质含量的影响。结果表明，适量施氮有利于提高灌浆中、后期的旗叶光合速率、旗叶PSU实际光化学效率，以及灌浆末期旗叶PSⅡ最大光化学效率；施氯过多不仅不能继续提高旗叶光合速率，而且使PSⅡ实际光化学效率降低。施氮有利于提高旗叶蔗糖含量，促进灌浆前期籽粒中蔗糖的供应；施氮较多的处理中，灌浆后期有较多蔗糖滞留于旗叶中，致使施氮处理间籽粒蔗糖含量无显著差异。与不施氮的处理相比较，施氮105～195kg·ha^-1显著提高籽粒产量，施氮105～240kg·ha^-1显著提高籽粒蛋白质含量；继续增施氮肥至285kg·ha^-1籽粒蛋白质含量、粒重和籽粒产量均降低。综合考虑籽粒产量和蛋白质含量，施氮量以150～195kg·ha^-1为宜。

A field experiment was conducted on high-yielding conditions to evaluate the effects of nitrogen fertilizer rate on changes of photosynthetic rate and photochemical efficiency in flag leaf, changes of sucrose content in flag leaf and grain after anthesis, and grain yield and protein content of winter wheat. The application of nitrogen fertilizer would increase photosynthetic rate and photochemical efficiency of ФPS Ⅱ in flag leaf during the mid and late filling stage, increase the ratio of Fv/Fm at the end of grain filling stage. With the application of excessive nitrogen, the photosynthetic rate do not increase and photochemical efficiency of ФPSⅡ decrease. The application of nitrogen fertilizer would increase sucrose content in flag leaf and promote sucrose supply in grain during early filling stages. During late filling stages, the nitrogen application at high rate would increase the amount of sucrose left in flag leaf, so the differences of sucrose content in grains among treatments of different nitrogen application rate were not significant. Compared with no nitrogen applied, the nitrogen application rate at 105～195 kg·ha^-1 increased grain yield significantly and the nitrogen application rate at 105～240 kg·ha^-1 increased protein content significantly. When the nitrogen application rate increased to 285 kg·ha^-1, grain weight, grain yield and protein content decreased. With the yield and protein content were concerned, the nitrogen application rate at 105～240 kg·ha^-1 was recommended.