一个光合作用光响应新模型与传统模型的比较

为了解决传统光合作用光响应模型(如直角双曲线和非直角双曲线模型)中光合速率虽沿着渐进曲线响应光照强度的增加,但拟合植物叶片的最大光合速率却远大于实测值,且无法给出光饱和点等问题。在对传统的光合作用光响应模型进行认真分析,发现其关键在于未考虑光呼吸的基础上,提出了一个新的光合作用光响应模型,详细讨论了该模型的主要特性,并与传统直角双曲线和非直角双曲线模型进行比较分析。用这3个模型拟合了不同试验条件下冬小麦光合作用光响应,结果表明:新模型较传统的模型更好地模拟不同温度及CO2浓度条件下冬小麦光合作用光响应,包括低光强条件下和光抑制条件下的光响应问题,且可求得最大光合速率、饱和光照强度、光补偿点和暗呼吸速率等。此外,新模型可以合理地描述植物叶片的光抑制,因此新模型具有普遍性。

Comparison of A New Model of Light Response of Photosynthesis with Traditional Models

Photosynthetic rates increase gradually with light intensity in the traditional models of light response curve of photosynthesis,i.e.rectangular hyperbolic model and nonrectangular hyperbolic model.So the maximum net photosynthetic rates calculated by nonrectangular hyperbolic model and rectangular hyperbolic model were far more than the measured data,and the saturation light point was not obtained.A new model of light-response of leaf net photosynthesis was proposed in this paper.Some properties of the new model of light-response of leaf net photosynthesis were discussed in detail.Results showed that the data of light-response of leaf photosynthesis of winter wheat under different environmental conditions were modeled by three models.The results fitted by nonrectangular hyperbolic model,rectangular hyperbolic model and the new model were compared.In addition,the measured data of light response of photosynthesis under different temperatures and CO2 concentrations could be dealt with,and the main parameters of photosynthesis,i.e.the maximum photosynthetic rates,saturation light point,light compensation point and the rate of dark expiration could be calculated without any hypotheses.The response data of leaf photosynthetic rate to irradiance under low irradiance and photo inhibition could be fitted by the new model.The measured data of light response of photosynthesis under different temperatures,CO2 concentrations and light intensity,including at low photon fluxes and photo inhibition could be dealt with.The fitted results were tallied with very well the measured data.So the new model has generality.