砖厂废气污染对橡胶树光合生理特性的影响

选取砖厂废气排放方向种植的橡胶树（Hevea brasiliensis）品系＂云研77-2＂为研究对象,在距离砖厂200、400、600 m处设置3个研究点,研究分析砖厂排放废气污染对橡胶树光合参数的影响。结果表明：砖厂废气排放对3个不同距离处橡胶树叶片光合参数有显著影响（P〈0.05）。随着橡胶树与砖厂距离的缩近,即污染加剧,橡胶树叶片净光合速率（Pn）、气孔导度（Gs）、胞间CO2（Ci）、蒸腾速率（Tr）、最大光合速率（Pmax）、光饱和点（LSP）、暗呼吸速率（Rd）和叶绿素含量（Chl）均呈下降趋势;最大荧光（Fm）、可变荧光（Fv）和最大荧光比（Fv/Fm）也下降,初始荧光（Fo）升高。该研究结果证明,砖厂废气污染对橡胶树光合生理特性有显著影响：相距砖厂600 m范围内,越靠近砖厂,橡胶树叶片光合特性越低。

Effect of brickyard exhaust gas pollution on photosynthetic characteristics of Hevea brasiliensis

In order to study the effects of the brickyard emission pollution on photosynthetic parameters of Hevea brasiliensis,the rubber trees of ＂Yunyan 77-2＂ varieties at different distances（200,400 and 600 m respectively） from the exhaust gas pollution source were selected as the test material.The results showed that brickyard exhaust emissions have significant impacts on the leaf photosynthetic parameters of rubber trees at three different distances（P 0.05）.With the decrease of distance from pollution source,namely,with pollution aggravating,the leaf net photosynthetic rate（Pn）,stomatal conductance（Gs）,intercellular CO2（Ci）,transpiration rate（Tr）,maximum photosynthetic rate（Pmax）,light saturation point（LSP）,dark respiration rate（Rd） and chlorophyll content（Chl） decreased;the maximum fluorescence（Fm）,variable fluorescence（Fv） and maximum fluorescence ratio（Fv/Fm） also decreased;and the initial fluorescence（Fo） increased.Those results demonstrated that brickyard exhaust emission had obvious influences on the photosynthetic physiological characteristics of Hevea brasiliensis： within 600 m range,the closer the rubber trees to pollution source was,the lower of the leaf photosynthetic performance was.