中文摘要：

通过设置不同滴灌量的田间试验,研究了南疆春小麦光合特性和产量对水分的响应。结果表明：限量滴灌（轻度亏缺和重度亏缺）造成麦田土壤水分亏缺,单叶光合速率（Pn）和群体光合速率（CAP）降低,在扬花期单叶蒸腾速率（Tr）和群体呼吸速率（CR）也均低于适量灌水处理,同时限量滴灌处理单叶光合速率日变化中的＂午休＂现象明显,影响了叶片同化功能;过量灌溉造成小麦营养体增长过快,Pn、CAP、CR、叶源量（CLSC）虽然较高,但后期下降快,不利于有效产量形成,生产效率低;适宜滴灌处理（3 750 m3/hm2）的单叶、群体光合性能均处于优化状态,在生育后期（灌浆期）能较长时间保持高的Pn、WUE、CAP、CR和CLSC等,保证了籽粒发育和灌浆的养分需求,产量最高。

英文摘要：

The response of photosynthetic characteristics and yield of spring wheat to different drip irrigation amount was studied and the results showed that,limited drip irrigation（mild deficiency and serious deficiency） caused soil moisture deficit in wheat field,the single leaf photosynthetic speed（Pn） and the canopy apparent photosynthesis（CAP） reduced,and at flowering stage,the single leaf transpiration rate（Tr） and the canopy respiration rate（CR） were also lower than those in moderate drip irrigation.The diurnal variation of Pn in limited drip irrigation treatment had a distinct ＂nap＂ that significantly influenced assimilation function of leaves.The excessive irrigating accelerated vegetative growth,Pn,CAP,CR and canopy leaf source capacity（CLSC） were higher,but soon dropped quickly in later period, which did not favor yield forming efficiently.In suitable drip irrigation treatment（3 750 m3/hm2）, because the photosynthetic functions of single leaf and canopy were at optimized condition,Pn,WUE,CAP,CR and CLSC maintained higher lever in later period（filling stage） that guaranteed nutrient demand of grain growing and grouting,so the yield was the highest.