土壤水分下限对设施番茄光合特性影响及模型比较

Effects of Different Lower Limits of Soil Moisture on Photosynthetic Characteristics of Tomato in Solar Greenhouse and Comparison of Models

以番茄“粉保利”为材料,设置水分下限T1、T2、T3和T4(分别为田间持水率的45%、60%、70%和80%)四个处理,利用CIRAS-3光合仪测定系统,测定番茄果实膨大期光响应特性曲线,并用指数函数模型、直角双曲线模型、非直角双曲线模型和直角双曲线修正模型模拟光响应过程,探讨不同水分下限对番茄叶片光合特性的影响,为番茄栽培提供科学用水依据。结果显示:随水分下限的升高,灌水量增加,番茄叶片净光合速率(Pn)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)和气孔导度(Gs)均呈增加趋势,T4处理最高,T1处理最低。四个模型对番茄叶片光响应特征参数的模拟效果均较好,其中直角双曲线修正模型模拟值与实测值最为符合,其决定系数R2也最高。水分亏缺会对番茄光系统造成损伤,使叶片光合能力下降,以T4水分下限灌溉,可明显提高番茄叶片Pn。直角双曲线修正模型是不同水分下限番茄叶片光响应模拟最佳模型,其对于光抑制和水分胁迫阶段的光响应模拟,弥补了其他三个模型无法模拟的缺点。

To explore the effect of different water lower limits on the photosynthetic characteristics of tomato leaves and the simulation of light response process,so as to provide scientific water use basis for tomato cultivation.Using tomato“Fen bal li”as the material,Set the water lower limit T1,T2,T3 and T4(respectively 45%,60%,70%and 80%of the field water holding rate)four treatments,and use the CIRAS-3 photosynthetic measurement system to determine The light response characteristic curve of tomato fruit during the expansion period was used to simulate the light response process with exponential function model,right-angle hyperbolic model,non-right-angle hyperbolic model and right-angle hyperbolic modified model.With the increase of the lower limit of water,the amount of irrigation increased,and the net photosynthetic rate(Pn),transpiration rate(Tr),intercellular CO2 concentration(Ci)and stomatal conductance(Gs)of tomato all showed an increasing trend,T4 treatment is the highest,T1 treatment is the lowest.The four models have relatively good simulation effects on the characteristic parameters of tomato leaf light response,but the simulation value of the right-angle hyperbolic correction model is most consistent with the measured value,and its determination coefficient R2 is also the highest.Water deficit will damage the photosystem of tomato and reduce the photosynthetic capacity of the leaves.Irrigating with the lower limit of T4 water can significantly increase the Pn of tomato leaves.The right-angle hyperbolic modified model is the best model for simulating the light response of tomato leaves with different water lower limits.It can simulate the light response during the lightinhibition and water stress stages,and it makes up for the shortcomings that the other three models cannot simulate.