不同水氮耦合对小麦旗叶主要光合特性的影响

在防雨水泥池栽条件下,以周麦18和济麦20为研究材料,研究水氮耦合对小麦旗叶主要光合特性的影响.试验结果表明:当土壤相对含水量低于40%时,施氮处理小麦旗叶气孔导度降低,胞间CO2浓度升高,光合速率受非气孔因素制约而降低;当土壤相对含水量为45%~75%时,随着氮肥施用量的增加,小麦旗叶的光合速率、气孔导度不断增加,胞间CO2浓度逐渐减小,气孔因素制约了光合速率的提高;当土壤相对含水量高于75%时,氮素营养对小麦旗叶光合特性的促进作用减弱.

Effect of Water and Nitrogen Interaction on Main Photosynthetic Characteristics in Flag Leaves of Wheat

Effects of water and nitrogen interaction on main photosynthetic characteristics of wheat variety Zhoumai 18 and Jimai 20 were studied by pool cultivation under the rain proof shelter. The results showed that when the relative soil moisture content was below 40%, stomatal conductance of flag leaves decreased, while moisture intercellular CO_2 concentration increased with the increasing N fertilizer. The decrease of photosynthesis rate was limited by non-stomatal factor. When the relative soil moisture content was between 45% and 75%, with the increasing of N fertilization and SRWC, photosynthesis rate and stomatal conductance of flag leaves increased, while intercellular CO_2 concentration reduced. Increase in photosynthesis rate was limited by stomatal factor. Stimulative effects of nitrogen nutrition on flag leaves photosynthesis of wheat reduced when the relative soil moisture content was higher than 75%.