影响水稻叶片光合日变化因素的分析

 选择典型的干热天气,测定了盆栽水稻二九丰孕穗期的光合日变化及其影响因子,利用相关性分析和通径分析,考查了光强、叶温、胞间CO₂浓度、气孔导度、蒸腾速率和相对湿度对光合速率的影响。早晨8:30以前,光合速率的上升主要是光强造成的;光合速率在8:30达最大值,此后逐渐下降,其间光合速率的降低,尤其是“午睡”期间的下降,气孔因素是主要限制因子;下午14:30～18:00,光合速率与胞间CO₂浓度呈一定负相关,但未达显著水平，与光强、气孔导度、叶温和相对湿度有一定关系，相关系数达显著水平。

Major Factors on Diurnal Changes of Photosynthetic Rate

The rice cultivar Erjiufeng grown in pots were used to determine the diurnal changes of photosynthetic rate (Pn) and its major affecting factors, i. e. photosynthetic photon flux (PPF) , temperature, intercellularCO2 concentration (Ci), stornatal conductance (SC), transpiration, and relative humidity (RH). The relation between photosynthetic rate and its factors were analysed by the correlation analysis and path analysis. The PPF is themajor factor which affected Pn before 8: 30 am; The Pn reached the maximum values at 8: 30 am, and the middaydepression of Pn was caused by the lowering of stomatal conductance , The change of Pn from 14: 30 to 18: 00 werenegative correlation with Ci, significantly possitive correlation with PPF, SC, transpiration, leaf temperature andRH.