中文摘要：

为了明确荒漠绿洲区不同灌溉定额对春小麦光合特性及产量的影响,通过田间观测试验,分析了6种不同灌水定额对春小麦的叶片净光合速率、蒸腾速率、气孔导度日变化以及子粒产量的影响。结果显示,高灌溉定额下（360、420、480 mm）,春小麦叶片净光合速率和蒸腾速率曲线的变化曲线呈单峰曲线变化,无＂午休＂现象,而低灌溉定额下（0、240、300 mm）光合速率呈双峰曲线,有＂午休＂现象,同时高灌溉定额处理下的气孔导度大于低灌溉定额处理;土壤含水量与全生育期春小麦光合速率之间的关系式呈二次曲线关系,当土壤含水量增加到约12%~13%时,光合速率达到最大临界值,而后出现下降。W4处理下的春小麦叶片净光合速率和蒸腾速率高于其它处理,子粒产量、千粒重和水分利用效率（WUE）也最大,是适宜该地区春小麦生长的最佳灌溉量。可见,过度灌溉抑制了春小麦的光合速率,导致减产。同时,降低了春小麦的水分利用效率,造成水资源的浪费。

英文摘要：

In order to define the effects of different irrigation quotas on photosynthetic characteristics and yield of spring wheat in desert oasis,through the field observation and experiment,has analyzed the effects of six different irrigation quotas on the leaf net photosynthetic rate,transpiration rate,daily change of stomatal conductivity and grain yield of spring wheat. The results showed that： Under high irrigation quotas（ 360 mm,420 mm and 480mm）,the change curves of the spring wheat leaf net photosynthetic rate and transpiration rate were showed unimodal curve change,and no ＂noon break＂phenomenon. But under the low irrigation quotas（ 0,240 mm and 300mm）,the photosynthetic rate was showed bimodal curve,and existed a ＂ lunch break＂ phenomenon. At the same time,the stomatal conductance by high irrigation quota treatments was greater than the low irrigation quota treatments. The relationship of soil water content on photosynthetic rate of spring wheat in whole growth period was showed the quadratic curve. The photosynthetic rate was reached the maximum critical value when the soil water content was increased to about 12% to 13%,and then it was declined. The leaf net photosynthetic rate,transpiration rate,grain yield,thousand grains weight and water use efficiency（ WUE） total were the biggest under W4 treatment,it was the optimal irrigation amount for spring wheat growth in this areas. So,excessive irrigation was restrained the photosynthetic rate of spring wheat,caused the yield decreas,reduced the WUE and caused the waste of water resources.