模拟酸雨对茶树叶片光合色素含量及光合作用CO2响应的影响

Effects of Simulated Acid Rain on Photosynthetic Pigment Content and Photosynthetic CO2 Response of Tea Leaves

为探究模拟酸雨对茶树叶片光合生理的影响,使用盆栽湘妃翠茶树幼苗作为实验材料,对其进行模拟酸雨处理,酸雨浓度梯度为pH 2.5、pH 3.5、pH 4.5,自来水作为对照,检测模拟酸雨对茶树幼苗叶片光合色素含量以及光合作用CO2响应曲线的影响。结果表明:pH 4.5与pH 3.5模拟酸雨处理对茶树幼苗叶片叶绿素a、叶绿素b以及类胡萝卜素含量无显著性影响,pH 2.5模拟酸雨处理使其含量显著降低;光合作用CO2响应曲线使用直角双曲线模型进行拟合,pH 2.5模拟酸雨组初始羧化效率(carboxylation efficiency, CE)、光合能力(Amax)显著低于对照组,pH 4.5处理组光合能力(Amax)显著升高,其他处理组羧化效率(CE)、光合能力(Amax)无显著变化;不同p H值模拟酸雨处理对CO2补偿点(carbon dioxide compensation point, CCP)、CO2饱和点(carbon dioxide saturation point, CSP)、光呼吸速率(Rp)无显著性影响。研究表明,重度模拟酸雨(pH 2.5)对茶树幼苗叶片光合作用产生抑制作用,茶树幼苗对pH 3.5和pH 4.5模拟酸雨有较强的耐受能力。

To explore the effects of simulated acid rain on photosynthetic physiology of tea leaves, using potted tea seedlings, potted Xiangfeicui tea seedlings were used as experimental materials to simulate acid rain treatment.The concentration of acid rain was pH 2.5, pH 3.5 and pH 4.5, and tap water was used as a control. The effects of simulated acid rain on the content of photosynthetic pigment and photosynthesis Ci curves of tea seedlings were detected. The results showed that pH 4.5 and pH 3.5 simulated acid rain had no significant effect on chlorophyll a,chlorophyll b and carotenoid content in leaves of tea seedlings, and the pH 2.5 simulated acid rain treatment made its content decrease significantly. The CO2 response curve of photosynthesis was fitted with a rectangular hyperbolic model. The carboxylation efficiency(CE) and photosynthetic capacity(Amax) of the pH 2.5 simulated acid rain group were significantly lower than those of the control group, the photosynthetic capacity(Amax) increased significantly in the pH 4.5 treatment group, but the CE and Amaxof other treatments did not change significantly.Simulated acid rain treatments with different pH values had no significant effect on CO2 compensation point(CCP), CO2 saturation point(CSP) and photorespiration rate(Rp). The results showed that heavy simulated acid rain(pH 2.5) inhibited photosynthesis of tea seedlings, and the seedlings had strong tolerance to simulated acid rain at pH 3.5 and p H 4.5.