单 位：
井冈山大学生命科学学院;井冈山大学数理学院;温州市农业科学研究院
关键词：
光响应机理模型;光能利用效率;水分利用效率;大豆;CO2浓度
摘 要：
CO_2是光合作用的原料和底物,影响着光合作用的进程和光合产物的数量.利用Li-6400-40B同时测量大豆叶片在不同CO_2浓度(300、400、500和600μmol·mol-1)下的光合电子传递速率和光合作用对光的响应曲线,并用构建的光合作用对光响应机理模型拟合这些光响应曲线,获得大豆叶片一系列的光合参数、生理生态参数和捕光色素分子的物理参数.结果表明:电子利用效率、最大电子传递速率和最大净光合速率随CO_2浓度的升高而增加;光补偿点和暗呼吸速率随CO_2浓度的升高而下降;光能利用效率和内禀(瞬时)水分利用效率随CO_2浓度的升高而增加,不同CO_2浓度下的最大光能利用效率和最大内禀(瞬时)水分利用效率之间存在显著差异,但不同CO_2浓度下的最大羧化效率的差异不显著.CO_2浓度的大小对光合作用中原初光反应存在一定程度的影响,即高CO_2浓度有利于减小捕光色素分子处于最低激发态的最小平均寿命,以提高光能传递的速度及增加大豆光合电子流的利用效率.
译 名：
Photosynthetic physio-ecological characteristics in soybean leaves at different CO_2 concentrations
作 者：
YE Zi-piao;KANG Hua-jing;DUAN Shi-hua;WANG Yi-juan;College of Maths &Physics,Jinggangshan University;Wenzhou Academy of Agricul-tural Sciences;School of Life Sciences,Jinggangshan University;
关键词：
mechanistic model of light-response;;light-use efficiency;;water-use efficiency;;soybean;;CO2 concentration
摘 要：
The availability of CO_2,a substrate for photosynthesis,affects the photosynthesis process and photosynthate production. Using the Li-6400-40 B,we measured the photosynthetic electron transport rate and the photosynthetic light-response curves of soybean( Glycine max) leaves at different CO_2 concentrations( 300,400,500 and 600 μmol ·mol~(-1)). By fitting these parameters with a mechanistic model characterizing the light response of photosynthesis,we obtained a series of photosynthetic parameters,eco-physiological parameters,as well as the physical parameters of photosynthetic pigments. The results showed that the electronic use efficiency,maximum electron transport rate,and maximum net photosynthetic rate increased with the increase of CO_2 concentration.The light compensation point and dark respiration rate decreased with the increase of CO_2 concentration. In addition, the light-use efficiency and intrinsic( instantaneous) water-use efficiency increased with the increase of CO_2 concentration,and their values differed significantly among different CO_2 concentrations. There was no significant difference on the maximum carboxylation efficiency among different CO_2 concentrations. Those results suggested that CO_2 concentration could affect the primary light reaction of photosynthesis in soybean leaves, and thus higher CO_2 concentration could decrease the minimum average lifespan of excitons at the lowest excited state,which would enhance the velocity of light energy transport and the use efficiency of photosynthetic electron flow.
