水分胁迫下施氮量对春小麦旗叶生理特性的影响

Effect of Nitrogen Application Rate on Physiological Characteristics in Flag Leaf of Spring Wheat under Water Stress

【目的】研究在水分胁迫下施氮量对抗旱春小麦品种花后旗叶生理特性的影响。【方法】在大田试验条件下，以抗旱春小麦新品种新旱688为实验材料。以大田常规灌水为对照，以全生育期灌水两次为胁迫；采用0、150、300和450kg／hm。四种氮处理，研究水分胁迫下氮肥用量对新旱688主要生理特性的影响。【结果】水分胁迫下，在一定的施氮范围内叶片中Chl（a＋b）、Chla、Chlb、全N含量随着施氮量的增加而增加，Chla／Chlb值随着施氮量的增加逐渐减小。在0—300kg／hm。施氮范围内净光合速率升高，胞间CO2浓度降低，当施氮量达到450kg／hm2时，胞间CO2浓度开始升高，光合速率反而下降。干旱时适当施氮有利于可溶性糖的积累，在150kg／hm2氮素水平时可溶性糖积累量高于其他氮素水平。【结论】水分胁迫下，适当施用氮肥有利于小麦花后旗叶生理特性的改善。

[ Objective ] The project aims to study the effect of nitrogen rate on flag leaf physiological char- acteristics by using Xinhan 688, a new variety of drought - resistance in the field experiment after flowering un- der water stress. [ Method ] Conventional irrigation drought stress in the whole growth period, and others to study the effect of nitrogen fertilizer and irrigation was taken as the control and two times of irrigation as were nitrogen application rate with 0,150,300,450 kg,/ha on physiological characteristics in Xinhan 688 [ Result] The content of Chl （a ＋ b）, Chla, Chlb, total N of leaf varied with nitrogen rate under drought stress in certain nitrogen application rate, the ratio of Chla/Chlb gradually decreased with increasing amount of nitrogen. The net photosynthetic rate was increased, and the intercellular CO2 concentration was decreased in the range of 0 -300 kg/ha nitrogen. When nitrogen rate reached to 450 kg/ha, the intercellular CO2 concentration began to in- crease, but the photosynthetic rate decreased. The high nitrogen in drought were generally most effective in the accumulation of soluble sugar, and the accumulation of soluble sugar with 150 kg/ha nitrogen was higher than that of other treatments. [ Conclusion ] The nitrogen application of different nitrogen levels had effect on the physiological characteristics of wheat flag leaf after anthesis under water stress.