在高肥条件下，研究了不同水氮组合对强筋小麦品种济麦20籽粒产量、蛋白质含量、蛋白质组分和籽粒品质的影响。结果表明影响小麦籽粒品质的主导因素是灌水。相同施氮水平下，各灌水处理的籽粒蛋白质含量、单体蛋白含量均显著低于不灌水处理，但不同灌水处理间无显著差异。随灌水次数增加，不溶性谷蛋白(高分子量谷蛋白)含量呈下降趋势，可溶性谷蛋白(低分子量谷蛋白)含量呈上升趋势，谷蛋白聚合指数（不溶性谷蛋白含量/谷蛋白总量）降低，粉质仪参数（面团稳定时间和形成时间）也相应降低，表明灌水次数增加导致籽粒品质变劣的主要原因是不溶性谷蛋白积累减少。施氮168 kg/hm2条件下，氮肥拔节期全量追施处理的籽粒产量不降低，而其籽粒品质显著优于分次施肥处理（50%基施、50%拔节期追施），且与240 kg N/hm2分次施用处理差异不显著。因此，在高产水平下，氮肥全量追施可作为兼顾籽粒产量和品质的推荐运筹模式。
Many studies have indicated that irrigation and nitrogen fertilizer are the major factors influencing wheat quality. Protein content, protein composition and size distribution of glutenin in wheat grain are significantly modified by the rate and timing of nitrogen fertilizer. It is also found that irrigation has diluting effect on grain quality and this effect is lessened by more nitrogen application. Although the respective effect of irrigation and nitrogen fertilizer on wheat quality has been extensively studied, especially in arid area and under low yield condition, it is little known about the coupling effects of irrigation and nitrogen on wheat quality under high yield condition. In this experiment, with a new method of protein fraction extraction, the effect of different irrigation and nitrogen application regimes on grain yield, protein content, protein composition and grain quality of Jimai 20 (a winter wheat cultivar with strong gluten) was investigated on high fertility soil in order to find the optimal regime of irrigation and nitrogen with high grain yield and excellent quality. The result indicated that irrigation was a crucial factor influencing grain quality. The contents of grain protein and monomeric protein in irrigation treatments were significantly lower than these in non-irrigation treatment, but there were no significant differences among irrigation treatments. Soluble glutenin (low molecular weight glutenin) content was increased while insoluble glutenin (high molecular weight glutenin) content and polymerization index (insoluble glutenin/total glutenin) were reduced as irrigation frequency added. In addition, both dough development time and stability time had the same tendency as insoluble glutenin and polymerization index, which suggested retarded formation and accumulation of insoluble glutenin was the major reason of worsen grain quality with added irrigation frequency. Compared with N split application (50% of total N fertilizer was applied at preplanting and the remainder at jointing), N fertilizer totally top-dressed at jointing led to significantly improved grain quality and similar grain yield. Therefore, it is proposed that N fertilizer can be totally top-dressed at jointing under high yield condition for the sake of high grain yield and excellent quality.
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