在田间池栽条件下，分别于小麦（品种：`济南17‘ 和 `鲁麦21‘）(Triticum aestivum cv. `Jinan17‘ and `Lumai21‘) 灌浆的前期（开花后1～10 d）, 中期（11～20 d）和 后期（21～30 d）进行了遮去50%光合有效辐射的试验，研究了产量和品质的变化及其生理 原因。主要结论如下：1）弱光条件下，光合物质生产均受到严重抑制，产量下降，容重降 低；植株的氮素积累量减少、向子粒分配的比例低，但子粒蛋白质含量、湿面筋含量升高，其中，子粒灌浆前期遮光升高的幅度最大。2）遮光后小麦子粒麦谷蛋白和醇溶蛋白含量均升高，但麦谷蛋白升高的幅度大于醇溶蛋白，使麦谷蛋白与醇溶蛋白的比例升高，麦谷蛋白大聚合体(GMP)含量 也升高，粉质仪参数也显著提高；子粒灌浆前期或中期遮光对上述指标的影响则较小，子粒 品质的形成与灌浆后期的光照条件关系更为密切。3）灌浆期相对较弱的光照强度对改善品质有利，但以降低产量为代价，两个品种的小麦所表现出的趋势基本一致。
Changes in the yields and quality, and the physiological response of w heat (Triticum aestivum cv. `Ji‘nan17‘ and `Lumai21‘) grown under low light intensities (50% PPFD) at different filling stages were studied. Wheat was p lanted in 2.5 m×2.0 m plots. The plots were shaded with white fabric that filtered 50% PPFD during three different filling stages: 1-10, 11-20, and 21-30 days afte r anth esis. Protein accumulation rate, nitrogen accumulation and distribution, kernel weight and yield, test weight, protein composition, protein content, wet gluten content, glutenin macropolymer (GMP) content, starch and protein quality were me asured. The results showed that under 50% PPFD, wheat yield and test weight deceased sharply (p<0.05), less nitrogen was distributed to kernels (p<0 .05), bu t protein content and wet gluten content increased significantly (p<0.05), esp ecially at the early filling stage. At the late filling stage, gliadin and glute nin content, glutenin macropolymer (GMP) content and glutenin/gliadin index incr eased significantly (p<0.05). Thus, farinogram parameters, such as water a bsor ption and dough stability time, improved at low light intensities (p<0.05) . Ho wever, these parameters changed only slightly during the early and middle fillin g stages (p>0.05), which suggested that the late filling stage is an impor tant stage during which light intensity influences protein quality. Shading or lower light intensity improved wheat quality, but yields decreased sharply, especiall y during the early grain filling stage. The two varieties, `Ji‘nan17‘ and `Lumai 2 1‘, showed similar responses to light levels at the different filling stages. Th erefore, future investigations should be conducted to resolve the conflict betwe en differences in yield and quality.