葡萄光合作用光响应曲线拟合模型比较研究

Comparison of Light-response Curve Fitted Models for Grape

通过分析各模型求取的光合参数模拟值与实测值的接近程度,探讨了各模型在葡萄光响应曲线研究中的适用性。为了筛选适合吐鲁番地区的葡萄光响应模型,采用二次多项式模型、指数函数模型、直角双曲线模型、非直角双曲线模型和修正的直角双曲线模型对葡萄光合作用的光响应曲线进行拟合,表明:指数函数模型和直角双曲线模型不能解释光饱和区域的光抑制现象。二次多项式在一定程度上能够体现出葡萄光合作用的光抑制现象,但各项光合参数与实测值相差较大,且有违背常识错误。非直角双曲线模型虽能解释光饱和区域的光抑制现象,但拟合得到的最大净光合速率高于实测值。修正的直角双曲线模型求解得到的各项光合参数均接近实测值,并且能很好地体现葡萄在不同光强下的光响应曲线,尤其是在光饱和区域。吐鲁番地区葡萄光响应模型宜采用修正的直角双曲线模型,其拟合求取的葡萄最大净光合速率、光饱和点、光补偿点、暗呼吸速率分别为10.627、1 178.362、67.487、2.943μmol/(m^2·s),初始量子效率为0.05。

The optimal model with the most closeness between measured and simulated value was selected. In order to find the best photo-response model of grape leaf in Turpan area, the photosynthetic response curve of grape leaf was fitted by quadratic polynomi- al, rectangular hyperbolic, exponential, rectangular hyperbolic, non-rectangular hyperbolic and modified rectangular hyperbolic mod- el. Showed that the exponential and rectangular hyperbolic model could not explain the photosynthetic suppress phenomenon of light saturation region. To some extent, the quadratic polynomial model displayed photosynthetic suppress phenomenon, but it had a very large difference between simulated photosynthetic parameters and measured ones, which defied common sense. The non--rectangular hyperbolic model explained the photosynthetic suppress phenomenon, but the fitted maximum net photosynthetic rate was higher than the measured values. The modified rectangular hyperbolic model with the most closeness between simulated value photosynthet- ic parameters and measured ones could best reflect the photosynthetic response curve for grape leaf under different light intensities, especially at the light saturation region. Whose fitted net photosynthetic rate （Amax）, light saturation point （LSP）, light compensa- tion point （LCP）, dark respiration rate （Rday） and the initial quantum efficiency （a） was 10. 627, 1 178. 362, 67. 487, 2. 943 μmol/ （m2 · s） and 0. 05. The modified rectangular hyperbolic model is suit to simulate the photosynthetic response curve for grape leaf un- der different light intensities at Turpan area.