水稻冠层不同高度光合有效辐射动态与叶片光合作用特性研究  

Dynamics of Photosynthetic Active Radiation and Photosynthetic Characteristics of Rice Leaves at Two Canopy Heights

作　　者：朱婷 康辉星 柯心然 张炎 ZHU Ting;KANG Huixing;KE Xinran;ZHANG Yan(Institute of Ecology,College of Urban and Environmental Sciences,Peking University,Beijing 100871)

机构地区：[1]北京大学城市与环境学院生态学系,北京100871

出　　处：《北京大学学报（自然科学版）》2021年第4期723-732,共10页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：北京大学植物功能生态学重点研究团队建设项目(7101302307);国家自然科学基金(41530533);北京大学城市与环境科学学院重点实验室项目(7100602014)资助。

摘　　要：在当前CO_(2)环境以及600μmol/mol air的开顶箱中,测量水稻冠层离水田泥土45 cm和90 cm处光合有效辐射的变动以及叶片的动态光合速率,探讨高CO_(2)环境下光强变动与光合作用关系的潜在变化。结果表明:1)水稻冠层90 cm处的平均光强是45 cm处的3~4倍,但晴天光强的时间变异系数比45 cm处低55%~60%;2)上部叶片有更高的饱和光合速率以及照后CO_(2)固定,下部叶片有较高的低光光合速率;3)高CO_(2)开顶箱冠层内部的光衰减百分比倾向于增大,上,下叶片的光合能力差异增大。因此,冠层不同高度的光环境可能同时影响叶片的稳定态和动态光合特性,高CO_(2)可能加大由不同冠层光环境差异造成的光合特性差异。The purpose of this study is to explore the potential changes in the relationship between dynamic light and photosynthesis in high CO_(2)environment,so as to provide scientific support for coping with global changes.We characterized dynamic light environment at two heights within rice canopy and dynamic photosynthetic response of leaves at each height(about 45 cm or 90 cm high from the soil of paddy field)in an open canopy and within an open top chamber(OTC)with a high CO_(2)of 600μmol/mol air.The result showed that the averaged photosynthetic photon flux density incident at 90 cm height above the paddy field was 3-4 times higher than that at 45 cm height,but the coefficient of temporal variation in light received at 90 cm height was 55%-60%smaller than that of the lower layer.Flag leaves at 90 cm height showed higher saturated photosynthetic rate and more post-illumination CO_(2)fixation,while leaves at 45 cm height showed higher photosynthetic rate under low light.In the high CO_(2)OTC,light attenuation percentage in canopy tended to increase,compared with leaves outside the OTC;the difference between assimilation rates at the two heights also increased within the OTC.These results suggested that not only the steady-state photosynthetic rate,but also the dynamic photosynthesis in rice leaves may have altered in different ways at different canopy heights,which is to be further influenced by CO_(2)environment.

关 键 词：动态光合 CO_(2)升高 光驯化 水稻 

分 类 号：S511[农业科学—作物学]