水分与氮素营养对辽春10号小麦旗叶光合作用的影响

在盆栽条件下,研究不同水分条件下氮素营养对辽春10号春小麦籽粒灌浆期旗叶光合特性的影响.结果表明,随着土壤水分状况的改善,春小麦的光合作用不断增强.土壤相对合水量低于45%时,施氮处理春小麦旗叶气孔导度、蒸腾速率和WUEleaf降低,胞间二氧化碳浓度升高,光合速率受非气孔因素制约而降低.当土壤相对含水量在45%～75%时,随着氮肥施用量的增加和土壤相对含水量的提高,春小麦旗叶的光合效率、气孔导度、蒸腾速率和WUEleaf不断增加,胞间二氧化碳浓度逐渐减小,气孔因素制约了光合效率的提高.当土壤相对含水量高于75%时,氮素营养对春小麦旗叶光合的促进作用减弱.

Effects of nitrogen nutrition on flag leaves photosynthesis of spring wheat Liaochun 10 under different relative soil water content

A pot experiment was conducted to study the effect of nitrogen nutrition on flag leaves photosynthesis at the tilling stage of spring wheat Liaochun 10 under different soil water content.The results showed that the photosynthesis of spring wheat was strengthened with the increasing of SRWC.Under the condition of the relative soil water content below 45 percent,the stomatal conductance,transpiration rate and WUEleaf in flag leaves decreased,while the intercellular CO2 concentration increased with the increasing N fertilizer.The decrease of photosynthesis rate was limited by non-stomatal factor.When the relative soil water content was between 45 and 75 percent,with the increasing of N fertilization and SRWC,photosynthesis rate,stomatal conductance,transpiration rate and WUEleaf increased,while intercellular CO2 concentration reduced.The increase of photosynthesis rate was limited by stomatal factor.The stimulative effects of nitrogen nutrition on flag leaves photosynthesis of spring wheat reduce under the condition of the relative soil water content beyond 75 percent.