短期UV-B辐射对青藏高原美丽风毛菊PSⅡ光化学效率的影响  

Effects of short term enhanced UV-B radiation on the PSⅡ photochemical efficiency of alpine plant Saussurea superba

作　　者：师生波[1] 尚艳霞[1,2] 朱鹏锦[1,2] 杨莉[1,2] 

机构地区：[1]中国科学院西北高原生物研究所/高原生物适应与进化重点实验室,西宁810001 [2]中国科学院研究生院,北京100049

出　　处：《应用生态学报》2011年第5期1147-1154,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(30670307;30570270;30170154);国际科技合作计划重点项目(2002CB714006)资助

摘　　要：通过短期增补UV-B辐射模拟试验,研究了青藏高原典型天气(晴天、多云、阴天)下高山植物美丽风毛菊叶片的叶绿素荧光参数变化.结果表明:随天气由晴变阴,美丽风毛菊叶片暗适应3min的PSⅡ最大光化学量子效率(Fv/Fm)显著升高,实际PSⅡ光化学效率(ΦPSⅡ)和光化学猝灭系数(qP)也升高,而非光化学猝灭系数(NPQ)则降低,可见光辐射(PAR)是影响PSⅡ光能转化效率的主要因素.增补UV-B辐射后,3种典型天气下,美丽风毛菊叶片的Fv/Fm和NPQ略有降低,ΦPSⅡ和qP略微增加,但对光合气体交换过程没有产生负影响.叶片净光合速率Pn和ΦPSⅡ的增高趋势与增补UV-B辐射下相对较多的UV-A成分有关,同时也得益于叶片厚度的增加.UV-B辐射对叶片光合机构具有潜在负影响.A simulation experiment of short term supplementation of UV-B was conducted to study the changes of chlorophyll fluorescence coefficients of alpine plant Saussurea superba under three typical weather conditions（sunny,cloudy,and shady） in Qinghai-Tibet Plateau.When the weather changed from sunny to shady,the maximal quantum efficiency of PS Ⅱ photochemistry（Fv/Fm） after 3 minutes of dark adaptation increased significantly,the actual photochemical efficiency of PSⅡ（ΦPSⅡ） and photochemical quenching（qP） also increased,but the non-photochemical quenching（NPQ） decreased,demonstrating that PAR was the main factor affecting the PSⅡ photochemical efficiency of S.superba.After the short term supplementation of UV-B,the Fv/Fm and NPQ under the three typical weather conditions had a slight decrease but the ΦPSⅡ and qP had a slight increase,while the photosynthetic gas exchange had less change.The increasing trend of net photosynthetic rate Pn and ΦPSⅡ under enhanced UV-B radiation could be related to the existence of more UV-A component,and also,benefited from the increased leaf thickness.UV-B radiation had potential negative effects on leaf photosynthetic components.

关 键 词：美丽风毛菊 叶绿素荧光 PSⅡ光化学效率 青藏高原 UV-B辐射 天气 

分 类 号：Q945.11[生物学—植物学]