中文摘要：

在大田超高产条件下,研究了氮磷肥配施对超高产冬小麦济麦22灌浆期光合日变化及产量的影响.结果表明：对照（不施氮磷肥）和低氮低磷处理（N、P分别为225和75 kg·hm^-2）的净光合速率（Pn）日变化均呈双峰曲线,有明显的光合＂午休＂现象,而合理的氮磷处理（N2P2,N、P分别为300和150 kg·hm^-2）可以减弱甚至使光合＂午休＂现象消失;＂午休＂现象的产生是气孔因素与非气孔因素共同作用的结果.随施肥量增加,小麦的Pn、气孔导度（Gs）、气孔限制值（Ls）和蒸腾速率（Tr）均逐渐增强.磷素对小麦光合作用的影响程度小于氮素,当施磷量超过150 kg·hm^-2时,小麦Pn随施磷量的增加程度有所减缓,甚至下降,各处理中以N2P2处理Pn、Gs和水分利用效率与对照差异最显著.表明氮肥对超高产小麦光合日变化有较大的调节作用,磷肥次之,而氮磷肥配施对Pn、Gs、Tr存在极显著的互作效应.当N、P分别为300和150 kg·hm^-2时有利于提高超高产冬小麦的Pn和产量.

英文摘要：

Taking super high-yielding wheat cultivar Jimai 22 as test material,a field experiment was conducted to study the effects of combined application of nitrogen （N） and phosphorus （P） on the diurnal variation of photosynthesis at grain-filling stage and the grain yield of the cultivar.In treatments CK （without N and P application） and low N/P application （ 225 kg N ·hm^-2 and 75 kg P ·hm^-2） ,the diurnal variation of net photosynthetic rate （ Pn） was presented as double-peak curve,and there existed obvious midday depression of photosynthesis.Under reasonable application of N/P （ 300 kg N·hm^-2 and 150 kg P ·hm^-2,treatment N2P2） ,the midday depression of photosynthesis weakened or even disappeared.Stomatal and non-stomatal limitations could be the causes of the midday depression.Increasing N and P supply increased the Pn,stomatal conductance （Gs） ,stomatal limitation value （ Ls） ,and transpiration rate （ Tr） .Fertilizer P had less effects on the photosynthesis,compared with fertilizer N.When the P supply was over 150 kg·hm^-2,the increment of Pn was alleviated and even decreased.Among the fertilization treatments,treatment N2P2 had the highest Pn,Gs,and water use efficiency,being significantly different from CK.It appeared that fertilizer N had greater regulatory effect on the diurnal variation of photosynthesis,compared with fertilizer P,while the combined application of N and P had significant co-effect on the Pn,Gs,and Tr.A combined application of 300 kg N ·hm^-2 and 150 kg P ·hm^-2 benefited the enhancement of Pn and grain yield.