基于叶绿素荧光参数的栓皮栎叶片PSⅡ失活高温指标

High Temperature Index of PSⅡ Inactivation According to Chlorophyll Fluorescence of Quercus variabilis Leaves

利用Mini-PAM叶绿素荧光仪测定离体栓皮栎叶片高温胁迫下光系统Ⅱ(PSⅡ)最大量子产量Fv/Fm和实际量子产量ΔF/Fm’,以研究栓皮栎叶片高温胁迫下PSⅡ失活的温度指标。试验设35～55℃共10个高温处理,处理时间5～85min。结果表明,(1)PSⅡ最大量子产量Fv/Fm和实际量子产量ΔF/Fm’均随胁迫温度升高和处理时间延长而呈下降趋势,ΔF/Fm’的下降过程呈Logistic曲线形式;(2)高温胁迫显著影响栓皮栎叶片的光合作用,ΔF/Fm’降低50%的温度T50是PSⅡ失活的临界温度指标,可作为确定高温胁迫温度指标的特征点,栓皮栎的高温胁迫叶温指标为42℃。研究结果可用于栓皮栎高温胁迫强度和持续时间的定量分析,并为确定其它作物农业气象指标提供方法。

Using chlorophyll fluorescence instrument Mini-PAM,authors measured the Quercus variabilis leaves maximal and actual chlorophyll fluorescence quantum yield of photo system Ⅱ （Fv/Fm and △F/Fm＇） in order to study the temperature of photo system Ⅱ inactivation of Quercus variabilis leaves on high temperature stress.There were 10 high temperature treatments of 35 ～55℃ with treating time 5 ～ 85min.The results showed that （1） both Fv/Fm and △F/Fm＇ decreased with increase of heat stress temperature and increase of high temperature treating time; and the process of that △F/Fm＇ decreased could be simulated with Logistic curves; （2） High temperature stress clearly influenced photosynthesis of Quercus variabilis leaves ; the temperature of that △F/Fm＇ decreased 50% （T50） was limit temperature index of photo system Ⅱ inactivation,and could be taken as characteristic point of high temperature stress ; the high temperature tress index of Quercus variabilis was determined as 42℃.This paper is useful for analyzing the intensity and lasting time of high temperature stress of Quercus variabilis leaves,and providing methods of determining agricultural meteorology index of other plants.