水分调亏对冬小麦生理生态的影响

通过冬小麦盆栽试验，在不同时期给以不同的调亏灌溉处理，以研究不同生长时期水分亏缺和亏缺程度对冬小麦生理及生长特性的影响，为农田节水提供指导。冬小麦生长发育过程划分为4个阶段：返青—拔节初期，拔节—孕穗，孕穗—抽穗，开花—灌浆成熟。每个生育时期设置4个水分水平，结果表明：土壤水分调控对株高、叶面积、叶绿素含量、光合、蒸腾、水分利用效率等指标均有影响；水分胁迫使作物光合速率的峰值提前出现，这有助于胁迫处理的作物利用有限的土壤水分；蒸腾速率比光合速率对水分胁迫的反应更为敏感，更易受气孔调节的影响。

Effects of water stress on physiological and agronomic features of winter wheat

Pot experiments with four levels of soil moisture at different growing stages of winter wheat were carried out to study water stress on physiological and agronomic factors of winter wheat. The growing stage of winter wheat was divided into four stages: recovering-jointing, jointing-booting, booting-heading, flowering-maturing. Under different soil-water conditions, the physiological and agronomic factors of winter wheat were measured continually. The results show that water stress affected plant height, leaf area, chlorophyll content, photosynthesis, transpiration and water use efficiency (WUE). The time when the maximum points in diurnal change for leaf photosynthesis and transpiration rate appeared was earlier under water stress than that without water stress, which was beneficial for crop to use limited soil moisture more efficiently under stress condition. Transpiration was more sensitive to water stress than photosynthesis and transpiration rate was more readily controlled by stomatal conductance.