不同温度对钩栗光响应曲线拟合的影响

Effect of temperature on light response curve fitting of Castanopsis tibetana

以珍贵用材树种钩栗2年生幼苗为研究对象,采用LI-6400光合速率测试仪对钩栗成熟叶片的光合能力进行测定分析,在对钩栗25℃和45℃条件下的光合特征曲线进行拟合后发现5个模型间存在不同程度的差异。高温胁迫提高了钩栗对弱光的利用能力,也显著降低了钩栗的最大净光合能力;从模型的拟合效果来看,直角双曲线修正模型在常温时的模拟值与实际值和其他模型相比高出12.99%~30.57%,而在高温条件下却高出12.44%~26.91%,拟合效果最差;常温条件下指数模型、指数修正模型和非直角双曲线模型具有较好的拟合效果,但在高温条件下,非直角双曲线模型和指数修正模型的效果最好,综合强光照条件下钩栗的光合规律,非直角双曲线模型综合表现最佳。

Measuring and fitting the light response curve is one of the widely used methods when we cultivate the precious trees species. But as the difference among models and the genetic characters of tree species, the application of light response model is very important in the research of precious tree. The research were done in 2 years old seedlings of precious timber tree species of Castanopsis tibetana, using LI-6400 photosynthesis system to measure the photosynthesic characteristics of Castanopsis tibetana, compare 5 different light response models for the fitting of the characteristic data of the combination at 25~C and 45＂C, the results show： high temperature stress can enhance the ability of using weak light, and also significantly reduced the maximum net photosynthetic capacity; under normal temperature （25℃） the value of modified rectangular hyperbolic model （MRHM） is higher by 12.99% - 30.57% compare to other models and measured value, while higher by 12.44% - 26.91% under higher temperature （45℃）; compare all the models, under 25℃, exponential model （EM）, and modified exponential model （MEM） and non-rectangular hyperbolic model （NHM） have the best fitting effect, but under the condition of 45 ℃, NHM and EM are the best models; Compere the real value and parameters of photosynthetic curve, NHM is the best model without the influence of temperature.