关于氮素对高大气CO2浓度下C3植物光合作用适应现象的调节机理已有较为深入的研究,但对其光合作用适应现象的光合能量转化和分配机制缺乏系统分析。该文以大气CO2浓度和施氮量为处理手段,通过测定小麦(Triticum aestivum)抽穗期叶片的光合作用-胞间CO2浓度响应曲线以及荧光动力学参数来测算光合电子传递速率和分配去向,研究了长期高大气CO2浓度下小麦叶片光合电子传递和分配对施氮量的响应。结果表明,与正常大气CO2浓度处理相比,高大气CO2浓度下小麦叶片较多的激发能以热量的形式耗散,增施氮素可使更多的激发能向光化学反应方向的分配,降低光合能量的热耗散速率;大气CO2浓度升高后小麦叶片光化学淬灭系数无明显变化,高氮叶片的非光化学猝灭降低而低氮叶片明显升高,施氮促进PSII反应中心的开放比例,降低光能的热耗散;高大气CO2浓度下高氮叶片通过PSII反应中心的光合电子传递速率(JF)较高,而且参与光呼吸的非环式电子流速率(J0)显著降低,较正常大气CO2浓度处理的高氮叶片下降了88.40%,光合速率增加46.47%;高大气CO2浓度下小麦叶片JF-J0升高而J0/JF显著下降,光呼吸耗能被抑制,更多的光合电子分配至光合还原过程。因此,大气CO2浓度增高条件下,小麦叶片激发能的热耗散速率增加,但增施氮素后小麦叶片PSII反应中心开放比例提高,光化学速率增加,进入PSII反应中心的电子流速率明显升高,光呼吸作用被抑制,光合电子较多地进入光化学过程,这可能是高氮条件下光合作用适应性下调被缓解的一个原因。 The regulatory mechanism of nitrogen adaptation to photosynthesis of C3 plants under high atmospheric CO2 concentration has been studied in more depth, but there is no systematic analysis of photosynthetic energy conversion and allocation mechanisms for photosynthesis adaptation. In this paper, atmospheric CO2 concentration and nitrogen application rate were used as treatments to measure the photosynthetic electron transfer rate and distribution of photosynthesis-intercellular CO2 concentration response curve and fluorescence emission kinetic parameters of heading wheat (Triticum aestivum) Response of Photosynthetic Electron Transport and Partitioning of Wheat Leaves to Nitrogen Supply under Long - term High Atmospheric CO2 Concentration. The results showed that compared with normal atmospheric CO 2 treatment, more excitation energy of wheat leaves could be dissipated as heat in the high atmospheric CO 2 concentration. Increasing nitrogen could decrease the distribution of more excitation energy to the photochemical reaction direction The rate of heat dissipation of photosynthetic energy; the photochemical quenching coefficient of wheat leaves did not change significantly with the increase of atmospheric CO2 concentration, the non-photochemical quenching of high-nitrogen leaves decreased and the low-nitrogen leaves increased significantly. Nitrogen promoted the open ratio of PSII reaction center , And reduced the heat dissipation of light energy. The photosynthetic electron transfer rate (JF) of high nitrogen leaves through the PSII reaction center was higher under high atmospheric CO2 concentration, and the non-cyclic electron flow rate (J0) involved in photorespiration was significantly decreased Under high atmospheric CO2 concentration, the JF-J0 and J0 / JF of wheat leaves increased significantly, and the photosynthetic rate of photosynthesis decreased and the photosynthetic rate was increased by 88.40% and 0.45% respectively. Electrons are assigned to the photosynthetic reduction process. Therefore, under the condition of increasing atmospheric CO2 concentration, the heat dissipation rate of wheat leaf excitation energy increased, but the opening ratio of PSII reaction center of wheat leaves increased and the photochemical rate increased, and the electron flow rate into PSII reaction center was significantly increased , Photorespiration was inhibited and photosynthetic electrons were more likely to enter the photochemical process, which may be one of the reasons why the adaptive down-regulation of photosynthesis under high nitrogen conditions is alleviated.