5种光响应模型对小叶杨的适用性分析

The applicability analysis of five light response curves of photosynthesis in Populus simonii

采用Li-6400光合仪测定CO2400μmol·mol-1条件下小叶杨的光响应数据。分别采用直角双曲线修正模型、二次多项式模型、直角双曲线模型、非直角双曲线模型及指数模型对光响应曲线进行拟合,探讨5种模型对小叶杨的适用性。结果表明:直角双曲线、非直角双曲线及指数模型不能处理光抑制部分的光响应数据,且得到的最大净光合速率大于实测值,光饱和点远小于实测值;二次多项式虽能处理光抑制部分的光响应数据,但得到的光合参数有悖常识;直角双曲线修正模型不仅能处理光抑制部分的光响应数据,且拟合得到的各项光合参数均与实际相符,是拟合小叶杨光响应曲线的最适宜模型。

The light response data of Populus simonii were measured by Li-6400 at concentration of CO2400 μmol·mol-1.Modified rectangular hyperbola model,quadratic polynomial model,rectangular hyperbola model,non-rectangular hyperbola model and exponential model were used to fit the light response curves of Populus simonii,and the applicability of these five models to the Populus simonii were discussed. The results indicated that rectangular hyperbola model,non-rectangular hyperbola model and exponential model were incapable of dealing with the light response data of photoinhibition,and the calculated maximum net photosynthetic rates were bigger than the measured value,besides,the the calculated light saturation points were far lower than the measured;Although,the quadratic polynomial model can process data of photoinhibition,the resulting photosynthetic parameters were contrary to common sense;Rectangular hyperbola model not only could process light response data under photoinhibition,but also could get photosynthetic parameters which was conformity with reality.