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为深入探讨水氮互作对冬小麦光合的影响机制,在温室盆栽条件下,以冬小麦品种陇育216为材料,分析了不同土壤水分和氮素条件下冬小麦叶片气体交换和叶绿素荧光参数的差异。结果表明,在水分胁迫(35%FWC)和正常水分供应(70%FWC)下,从9:00到17:00,中氮(5mmol·L-1)处理小麦叶片净光合速率(Pn)显著高于低氮(2mmol·L-1)。与正常水分供应相比,水分胁迫均降低了Pn、气孔导度(Gs)和蒸腾速率(Tr)。增施氮肥可提高水分胁迫下的Gs、Tr和Rd,消除水分胁迫对Gs、Vc,max、Jmax、TPU和Fv/Fm的负效应,降低了qP和ETR。说明适度施氮可促进水分胁迫下气体交换、光能利用以及PSII的光化学反应和电子传递,从而提高冬小麦光合和对水分缺乏的适应能力。
In order to further explore the mechanism of water and nitrogen interactions on photosynthesis of winter wheat, the greenhouse wheat varieties Longyou 216 were used to analyze the differences of gas exchange and chlorophyll fluorescence parameters of winter wheat under different soil water and nitrogen conditions. The results showed that net photosynthetic rate (Pn) of wheat leaves treated with medium nitrogen (5 mmol·L-1) was significantly increased from 9:00 to 17:00 under water stress (35% FWC) and normal water supply (70% FWC) Higher than low nitrogen (2mmol · L-1). Compared with normal water supply, water stress reduced Pn, stomatal conductance (Gs) and transpiration rate (Tr). The addition of nitrogen fertilizer increased the Gs, Tr and Rd under water stress, eliminated the negative effects of water stress on Gs, Vc, max, Jmax, TPU and Fv / Fm, and reduced qP and ETR. The results showed that moderate nitrogen application can promote the gas exchange, light energy utilization and the photochemical reaction and electron transfer of PSII under water stress so as to improve photosynthesis and water stress tolerance of winter wheat.