不同种源地狼牙刺的光合光响应曲线及其模型拟合

Photosynthetic Light Response Curve and Its Model Fitting of Sophora davidii from Different Provenances

【目的】为筛选出与狼牙刺光合特性相适应的光响应模型,更好开展狼牙刺优良家系选育研究。【方法】采用直角双曲线模型、非直角双曲线模型、直角双曲线修正模型、指数模型对3个种源地2年生狼牙刺的光响应曲线进行拟合。【结果】结果表明:直角双曲线模型和非直角双曲线模型拟合结果与实测值差异较大,指数模型拟合结果虽接近实测值,但上述3种模型都无法处理因光抑制而净光合速率下降部分的曲线。直角双曲线修正模型与其他3种模型相比较,拟合得到的结果和实测值最为接近,并且克服了其他3种模型存在的问题。狼牙刺表观量子效率偏小,在0.025~0.035范围内,是由于狼牙刺所处的生长环境和生物学特性所致。【结论】直角双曲线修正模型与狼牙刺光合光响应曲线拟合较好,各参数与实测值较为接近,参数值合理,符合植物对于光变化的生理情况,建议对狼牙刺光响应曲线进行拟合时使用直角双曲线修正模型。

【Objective】This paper aims to select the optimum model of photosynthetic light-curve of Sophora davidii,and to better carry out the breeding research of the excellent families of Sophora davidii.【Method】Species were etermined using rectangular hyperbola,non-rectangular hyperbola,modifi ed ctangular hyperbola models and exponential equation model,in order to investigate which model was better close the photosynthetic light-curve of 2-year-old Sophora davidii from three regions.【Result】the rectangular hyperbola and non-rectangular hyperbola have large differences with the measured values,although the results of exponential model are close to the measured values,none of the above three models can deal with the curves in which the net photosynthetic rate decreases due to photoinhibition.Compared with the other three models,the ctangular hyperbola results are closest to the actual measured values,and overcome the problems of the other three models.The apparent quantum effi ciency of Sophora davidii is relatively small,in the range of 0.025 to 0.035,which is due to the growth environment and biological characteristics of Sophora davidii.【Conclusion】The modifi ed ctangular hyperbola model fi ts well with the photosynthetic light response curve of Sophora davidii.The parameters are relatively close to the actual measured values.The parameter values are reasonable and conform to the physiological conditions of plants for light changes.It is recommended to fi t the light response curve of Sophora davidii using the modifi ed ctangular hyperbola model.