修剪节位及修剪时期对四季蜜芒枝条生长及反季节开花的综合效应

Applications studies of the modified exponential model on photosynthesis—light response and CO2 response curves of Mirabilis jalapa

关键词:  紫茉莉  光合—光响应模型  光合-CO₂响应模型

Key words:  Mirabilis jalapa  photosynthesis-light response curve models  photosynthesis-CO₂ response curve models

摘要:

五种模型分别运用于紫茉莉的光合—光响应及CO₂响应曲线的拟合,研究其光合效率参数的变化,探讨紫茉莉光合—光响应及CO₂响应的最适模型。结果表明:(1)紫茉莉的光合—光响应及CO₂响应改进指数模型拟合R²均为0.999,拟合效果优于非直角双曲线、直角双曲线和直角双曲线修正模型。其饱和光强和最大净光合速率分别为797.299和7.879 μmolCO₂·m^-2·s^-1,饱和CO₂浓度和最大光合能力分别为1 264.447和16.783 μmol CO₂·m^-2·s^-1,均与实测值最接近;(2)五个模型拟合和预测的均方误差(MSE)、平均绝对误差(MAE),都是改进指数模型小于其他模型。改进指数模型为紫茉莉光合—光响应及CO₂响应曲线的最佳模型,实验结果可为紫茉莉的生理生态应用研究提供参考。

Abstract:

To study changes of photosynthetic efficiency parameters and explore the applicable model,five models were used to describe photosynthesis-light response and CO₂ response curves of Mirabilis jalapa,respectively. The results were as follows:(1)The light response and CO₂ response curves fitted R² of modified exponential model were both 0.999,the light saturation point and the maximum net photosynthetic rate were 797.299 μmol·m^-2·s^-1 and 7.879 μmol CO₂·m^-2·s^-1,respectively; the CO₂ saturation point and the photosynthetic capacity were 1 264.447 μmol·mol^-1 and 16.783 μmol CO₂·m^-2·s^-1 respectively,which most proximally fitted the measured values. The modified exponential model was superior to nonrectangular hyperbola model,rectangular hyperbola model,modified rectangular hyperbola model and exponetial model;(2)The mean square error(MSE)and mean absolute error(MAE)of fitted and predicted values in the modified exponential model were much lower than those in other models. In conclusion,the modified exponential model was optimal model for describing the photosynthesis-light response and CO₂ response curves of M. jalapa,which could provide a reference application in physio-and ecology of M. jalapa.