叶片光能利用效率和水分利用效率对光响应的模型构建

Model construction of light use efficiency and water use efficiency based on a photosynthetic mechanistic model of light response

基于光合作用对光响应新模型,以番茄(Lycopersicon esculentum)为例,构建了叶片尺度的光能利用效率(LUE)和水分利用效率(WUE)对光响应模型,并在此基础上比较了不同CO_2浓度(350、450、550和650μmol·mol-1)下番茄叶片的LUE和WUE等生理特性。结果表明:(1)光响应新模型可很好地拟合4种CO_2浓度下的番茄幼苗叶片的光合特性,拟合值与实测值高度吻合;(2)基于光响应新模型推导的叶片LUE模型(LUE-I模型)和WUE模型(WUE-I模型)也可以很好地拟合4种CO_2浓度下的番茄幼苗叶片的LUE和WUE与光强的关系,且拟合值同样与实测值高度吻合;(3)LUE-I模型和WUE-I模型还可分别给出相应的最大光能利用效率(LUE_(max))和最大水分利用效率(WUE_(max)),及其对应的饱和光强。综合本试验结果认为,新构建的LUE-I模型和WUE-I模型对研究叶片尺度的LUE和WUE对光强的响应是可行的。

At leaf level responses of light use efficiency（LUE） and water use efficiency（WUE） of Lycopersicon esculentum to light intensities（i.e. LUE-I model and WUE-I model） were developed based on a new model of light response of photosynthesis. At the same time, the LUE and WUE of tomato seedling leaves at CO2 concentrations 350, 450, 550 and 650 μmol·mol^-1 were measured by LI-6400, and then these measured data were fitted by LUE-I and WUE-I models, respectively. The results show that（1） the new model of light-response of photosynthesis could fit well the photosynthetical characters at different CO2 concentrations;（2） these developed models could describe well the LUE-I and WUE-I curves of tomato leaves in four CO2 concentrations, and all the fitted parameters were in very close agreement with the measured data;（3） both LUE-I and WUE-Imodels not only fit well the relationship between LUE（WUE） and light intensities, but also directly give the maximum light use efficiency（LUE（max）） and the maximum water use efficiency（WUE（max）） and their corresponding saturation light intensities. Based on the results mentioned above, it can be concluded that both LUE-I and WUE-I models are powerful tools to study the response of LUE and WUE to light intensities and investigate on eco-physiological characteristics of plants under different environmental conditions.