影响水稻光合午休的因素分析与响应曲面分析

Study on Midday Depression of Rice Photosynthesis by Factor Analysis and Response Surface Analysis

当光强达到1700μmolphotonm^-2s^-1，叶温超过35℃的晴天中午，水稻可产生明显的午休．通过光合午休过程中各因素与光合速率的相关性分析，采用R～2（决定系数）决定最佳回归分析所建立的复合回归模式，以此数学模型绘制响应曲面图．本文由数学分析，证实了午休过程中光合速率下降的主要限制因子是气孔导度；并分析了光合午休过程中，气孔导度与其它各因素的交互作用对光合速率的影响，揭示午休是在干热条件下，气孔导度减小，胞间CO_2浓度明显降低，光合原料短缺导致的光合速率下降．

Low level of Pn appeared at fine midday.The depression of Pn was not considered to be caused by PPF. The optimal regression models for ph otosynthetic rate were based on R square and correlation analysis.A decrease of Pn accompanied by a lowered Ci suggested that stomatal closure was the limiting factor.The interaction of stomatal conductance and other factors on photosynthetic rate were studied by using response surface,and the response surface of every mathematical models were drawn to express their intrinsic relationships.The study showed that lowering of stomatal conductance caused by low RH was the cause of midday depression of Pn.