模拟酸雨对龙眼叶片叶绿素a荧光特性的影响

Effect of Simulated Acid Rain on the Chlorophyll a Fluorescence Cha-racteristic of Longan(Dimorcarpus longana Lour.)Leaves

利用OS5 FL饱和脉冲调制式荧光测定仪研究了酸雨胁迫对龙眼叶片叶绿素a荧光特性的影响。结果表明 :在pH≤ 3.5的酸雨胁迫下 ,龙眼叶片叶绿素a荧光诱导动力学曲线发生明显变化 ,Fv/Fm、Fv/Fo、PSⅡ非环式电子传递的量子效率 (ΦPSⅡ )、荧光下降比值(Rfd)、光化学猝灭系数 (qP)和非光化学猝灭系数 (qN)均随酸雨pH下降而降低 ,说明酸雨抑制了PSⅡ的功能和碳同化能力。叶绿素含量下降主要是由于叶绿素a下降所致 ,叶绿素b对酸雨的反应不敏感。

The effects of acid rain stress on chlorophyll a fluorenscene characteristic of Longan leaves were studied by using OS5-FL modulated chlorophyll fluorometer.The results showed that chlorophyll a fluorescence induction kinetic curves of longan leaves were changed obviously at pH value below 3.5.The decrease of Fv/Fm,Fv/Fo,quantum yield of photosystem Ⅱ electron transport(ΦPSⅡ)and rate of fluorescence decrease(Rfd)indicated that the primary light energy conversion of PSII and the potential photosynthetic activities had been inhibited.The decline of photochemical quenching(q P)and non-photochemical quenching(q N)also implied the inhibition of carbon assimilation.The decrease of chlorophyll content was mainly resulted from the decrease of chlorophyll a.The chlorophyll b was less sensitive to acid rain.