施氮量对开花期超高产小麦旗叶CO2响应曲线的影响

为给未来大气CO2浓度升高条件下超高产小麦的氮肥管理提供技术支撑,在大田条件下利用LI-6400便携式光合作用测定仪,采用开放式气路测定了不同CO2浓度下小麦旗叶的净光合速率(Pn)、气孔导度(Gs)、胞问CO2浓度(Ci)、蒸腾速率(Tr)、水分利用效率(WUE)等相关指标,分析了施氮量对开花期起高产小麦旗叶CO2响应曲线的影响.结果表明,氮素对开花期超高产小麦旗叶的CO2响应有较大的调节作用,随着外界CO2农度的升高,小麦旗叶的先合参数Pn、WUE,逐渐上升并在800 μmol CO2·mol-1左右趋于稳定.但施氮量在375kg/ha条件下Pn、WUE反而较施氮量为300 kg/ha的降低.说明在合理的施氮范围内,施氮和提高外界CO2浓度能通过增强小麦旗叶对胞间CO2的利用能力来提高光舍速率、降低蒸腾速率、提高水分利用效率,从而改善旗叶的光合性能.

Effects of Different Amount of Nitrogen Supply on the CO2-response Curve in Flag Leaves of Superhigh-yield Winter Wheat at Flowering Stage

The effects of nitrogen supply on the CO2-response curve in flag leaves of superhigh-yield winter wheat at flowering stage were studied under field conditions to provide scientific and technological support for nitrogen management of the superhigh-yield winter wheat.The net photosynthesis rate(Pn),intercellular CO2 concentration(Ci),stomatal conductance(Gs)and transpiration rate(Tr)in superhigh-yield winter wheat were measured using LI-6400 Portable Photosynthesis System with an open flow gas exchange syste...