紫叶李叶片色素含量及叶绿素荧光动力学参数对SO2胁迫的响应  

Contents of photosynthetic pigments and chlorophyll fluorescence parameters in Prunus cerasifera var. atropurea leaves under SO_2 stress

作　　者：李彦慧[1] 孟庆瑞[1] 李向应[2] 李保国[1] 杨建民[1] 

机构地区：[1]河北农业大学,保定071000 [2]乌兰察布职业学院生物技术系,集宁012000

出　　处：《环境科学学报》2008年第11期2236-2242,共7页Acta Scientiae Circumstantiae

基　　金：国家林业局“948”项目(No.2001-40);河北农业大学科学研究基金项目~~

摘　　要：以盆栽紫叶李的2年生嫁接苗为试材,采用人工静态熏气装置分析了不同浓度SO2(0～22.8mg.m-3)胁迫条件下(16d)紫叶李叶片光合色素含量及荧光动力学参数的变化情况.研究结果显示:在SO2浓度为5.7mg.m-3的胁迫下,叶绿素a(Chla)、叶绿素b(Chlb)、Chla/Chlb、总叶绿素和类胡萝卜素(Car)含量均比对照增加,在其它浓度处理下均减小,且与对照间差异显著(11.4mg.m-3胁迫下叶绿素a和类胡萝卜素除外).在SO2浓度小于11.4mg.m-3时,紫叶李叶片花青苷和类黄酮含量随着胁迫强度的增强而增加(与对照间差异显著,p<0.01);而在SO2浓度大于11.4mg.m-3时则随着胁迫强度的增强而降低(与对照间差异显著,p<0.01).荧光动力学参数中,PSⅡ原初光能转化效率Fv/Fm随着胁迫强度的增强呈现先增加后降低的变化趋势,PSⅡ潜在活性Fv/Fo、光化学淬灭效率qP随着胁迫强度的增强而减小,而荧光非光化学淬灭效率qN却随着胁迫强度的增强而增加.研究结果表明,紫叶李苗木在低浓度SO2(小于11.4mg.m-3)胁迫下通过自身较强的保护系统使机体免受伤害;而在高浓度SO2(大于11.4mg.m-3)胁迫下通过增加qN耗散过剩的光能和提高ΦPSⅡ消耗多余能量来保护光合器官免受损伤,但叶片的光合色素含量和其它荧光参数均受到不同程度的影响,紫叶李叶片受到伤害与PSⅡ反应中心失活有关.Two-year-old pot-planted seedlings of Prunus cerasifera var.atropurea were studied to determine the effect of SO2 stress on photosynthetic pigments,anthocyanin and chlorophyll fluorescence parameters.Under SO2 treatment in a closed chamber at a rate of 5.7 mg·m^-3,the contents of chlorophyll a,chlorophyll b,chlorophyll a＋chlorophyll b,carotenoid increased,but the differences were not significant compared with the control.However for higher levels of SO2,these parameters decreased significantly compared with the control（except chlorophyll a and carotenoid under 11.4 mg·m^-3 SO2 stress）.As the stress increased,the content of anthocyanin and flavonoids increased at SO2 concentrations below 11.4 mg·m^-3,and decreased significantly at concentrations higher than 11.4 mg·m^-3.Considering the chlorophyll fluorescence parameters,Fv/Fm first increased and then decreased as the SO2 concentration increased,while qN increased at greater SO2 concentrations.Fv/Fo and qP decreased accordingly with the increase of SO2 concentration.We conclude that Prunus cerasifera var.atropurea could protect itself from damage through a highly active protection system under low SO2 concentrations（lower than 11.4 mg·m^-3）,while under higher SO2 concentrations（higher than 11.4 mg·m^-3）the protection mechanism could protect the photosynthetic apparatus from damage resulting from surplus light energy through increasing qN and ΦPSⅡ,but the photosynthetic pigments and the other chlorophyll fluorescence parameters were negatively affected.The results demonstrate that damage to the leaves of Prunus cerasifera var.atropurea is related to the inactivation of the PSⅡ reaction center.

关 键 词：紫叶李 SO2 光合色素 花青苷 荧光参数 

分 类 号：X171[环境科学与工程—环境科学]