灌水对节水小麦“衡观35”产量、蛋白质含量及光合性能的影响

水分是限制小麦产量和品质提高的关键因素。为探究不同时期灌水对冬小麦产量、农艺性状、籽粒品质及光合性能的影响，在自动防雨水肥控制池中设置4个春季水分处理：不灌水(对照，W1)、仅拔节期灌水1050m³/hm²(W2)、仅开花期灌水1050m³/hm²(W3)和拔节期525m³/hm²⁺开花期525m³/hm²(W4)。结果表明，W1处理籽粒蛋白质含量最高，W2处理蛋白质产量最高，W3处理籽粒产量最高，W4处理光合性能最稳定。与W1处理相比，灌水影响小麦旗叶的光合性能，使其净光合速率、气孔导度、胞间CO₂浓度和蒸腾速率增大；拔节期灌水可增加叶片叶绿素含量，促进植株干物质积累，提高籽粒蛋白质产量，通过增加单位面积穗数和穗粒数而增加生物产量；开花期灌水促进籽粒长、宽增大，增大库容量，通过增加粒重而提高籽粒产量。通过比较拔节期灌水后至开花期未灌水前W1、W4和W2处理发现，灌水使最大净光合速率和光饱和...

Effects of Irrigation on Yield,Protein Content and Photosynthetic Performance of Water-Saving Wheat “Hengguan 35”

Water is the key factor limiting the improvement of wheat yield and quality. In order to explore the effects of irrigation in different periods on winter wheat yield, agronomic characteristics, grain quality and photosynthetic performance, four water treatments were set under conditions of automatic rain-proof shelter that water and fertilizer were controlled: no watering (control treatment, W1), water 1050m³/ha at jointing stage (W2), water 1050m³/ha at flowering stage (W3), and water 525m³/ha at jointing stage + 525m³/ha at flowering stage (W4). The results showed that, the grain protein content of W1 treatment, the protein yield of W2 treatment and the grain yield of W3 treatment were the highest. W4 treatment had the most stable photosynthetic performance. Compared with W1 treatment, irrigation affected the photosynthetic performance of wheat flag leaves, increased its net photosynthetic rate, stomatal conductance, intercellular CO₂ concentration and transpiration rate. Irrigation at jointing stage increased leaf chlorophyll content, dry matter accumulation and grain protein yield, and increased biological yield by increasing the number of spikes and grains per spike. Irrigation at flowering stage could increase grain length and width, increase sink capacity, and increase grain yield by increasing weight. By comparing W1, W4 and W2 treatments after irrigation at jointing stage and before irrigation at flowering stage, it was found that irrigation increased the maximum net photosynthetic rate and light saturation point, decreased the dark respiration rate, and the flag leaf was more adapted to strong light, but could not further increase the photosynthetic efficiency, and the weakening range of flag leaf adaptation to strong light increased with time. With the same amount of irrigation, irrigation only once at flowering stage or twice at jointing stage and flowering stage could prevent the decline of photosynthetic performance and the early- senescence of leaves at the later stage. Therefore, attention should be paid to the role of water in different growth periods in production, and irrigation should be carried out in time according to the actual precipitation and production demand.