花生不同光响应曲线拟合模型的比较

The Study on Different Model Fitting Comparison of Photosynthesis Light Response Curves for Peanut(Arachis hypogaea L.)

为选择合适的数学模型来拟合花生光合—光响应曲线,本文比较分析了直角双曲线模型、非直角双曲线模型、指数函数、直角双曲线修正模型以及指数改进模型在模拟2个花生品种"泰花5号"和"中花16"的光合—光响应曲线中的拟合度。结果表明,5种典型的光响应模型均可对花生叶片的光合—光响应曲线进行模拟,决定系数均达0.99以上。由计算的光合参数可知,不同模型拟合两个品种的最大净光合速率均高于实测值,但以直角双曲线修正模型和指数改进模型的计算值最为接近实测值。由指数函数、直角双曲线修正模型与指数改进模型求解的饱和光强与实测值差异较小,而由直角双曲线与非直角双曲线求解得到的饱和光强与实测值差异较大。5个模型拟合的光补偿点均在实测值范围内且差异较小。泰花5号以直角双曲线修正模型和指数改进模型拟合的暗呼吸速率较为接近实测值,而中花16的暗呼吸速率以非直角双曲线的拟合值最为接近实测值。综合分析,直角双曲线修正模型和指数改进模型比较适合用于拟合花生的光响应曲线,尤其是直角双曲线修正模型可直接拟合光抑制参数。

In order to select the appropriate model of photosynthesis light response curve to invest photosynthetic characteristics of peanut, five typical models (rectangular hyperbolic model, non-rectangular hyperbolic model, exponential model, modified rectangular hyperbolic model, and modified exponential model) were adopted to fit the photosynthesis light response curves of two peanut (Arachis hypogaea L.) varieties (Tai-5 and Zhong-16). Results showed that all the five models could well fit the photosynthesis light response curves of the two peanut varieties (r^2 >0.99). All the five models overestimated the maximum net photosynthetic rate (Pnmax), while the modified rectangular hyperbolic model and the modified exponential model presented more realistic values. The values of light saturation point (Isat) estimated by exponential model, modified rectangular hyperbolic model, and modified exponential model were consistent with the measured data, however, the I sat values estimated by rectangular hyperbolic model and non-rectangular hyperbolic model were significantly different from the measured data. The estimated values of the light compensation point(Ic)by the five models were most close to the measured values. The estimated values of the rate of dark respiration (Rd) by modified rectangular hyperbolic model and modified exponential model were close to the measured values for Tai-5, and the R d values estimated by the non-rectangular hyperbolic model were close to the measured values for Zhong-16. All data suggested that the modified rectangular hyperbolic model and modified exponential model could well fit the photosynthesis light response curve for peanut to study the photosynthetic characteristics, especially the modified rectangular hyperbolic model could well estimate the light response curves of photo-inhibition part.