青藏高原强UV-B辐射对美丽风毛菊光合作用和色素含量的影响  

Effects of strong solar UV-B radiation on photosynthesis and photosynthetic pigment contents of Saussurea superba on Qinghai-Tibet Plateau

作　　者：师生波[1,2] 尚艳霞[2] 朱鹏锦[2] 张德罡[1] 

机构地区：[1]甘肃农业大学草业学院草业生态系统教育部重点实验室/中-美草地畜牧业可持续发展研究中心,兰州730070 [2]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

出　　处：《应用生态学报》2011年第1期53-60,共8页Chinese Journal of Applied Ecology

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

摘　　要：以青藏高原矮嵩草草甸的主要伴随种美丽风毛菊为材料,通过滤除太阳辐射光谱中UV-B成分的模拟试验,研究了强太阳UV-B辐射对高山植物光合作用、光合色素和紫外吸收物质的影响.结果表明:与对照相比,弱UV-B处理能促使美丽风毛菊叶片净光合速率增加和提高稳态PSⅡ光化学效率;对照中叶片厚度的相对增加能弥补单位叶面积光合色素的光氧化损失,是高山植物对强UV-B辐射的一种适应方式.短期滤除UV-B辐射处理时紫外吸收物质含量几乎没有变化,说明高山植物叶表皮层中该类物质受环境波动的影响较小.强UV-B环境下光合色素的相对增加是一种表象,而青藏高原强太阳UV-B辐射对高山植物美丽风毛菊的光合生理过程仍具有潜在的负影响.Taking the main companion species Saussurea superba in an alpine Kobresia humilis meadow on Qinghai-Tibet Plateau as test material,a UV-B exclusion experiment with UV-B excluding and UV-B transmitting filters was performed to study the effects of strong solar UV-B on the photosynthesis,photosynthetic pigments,and UV-B-absorbing compounds of S. superba,aimed to examine the adaptation capability of alpine plants to strong solar UV-B radiation. The removal of UV-B components from natural sunlight increased the net photosynthetic rate （P0.05） and PSⅡ photochemistry efficiency of S. superba. The relatively increased leaf thickness under ambient UV-B could compensate the photo-oxidation of photosynthetic pigments,an inherent characteristic of alpine plants growing in intense UV-B. Short-term removal of UV-B radiation had no obvious effects on the UV-B-absorbing compounds,suggesting that these compounds in epidermal layer of S. superba could hardly be affected by the environment. It was concluded that the increase of photosynthetic pigment contents due to the enhancement of leaf thickness was a specious phenomenon,but the strong solar UV-B radiation on Qinghai-Tibet Plateau still had a potential negative impact on the photo-physiological processes in alpine plant S. superba.

关 键 词：高山植物 光合作用 PSⅡ光化学效率 青藏高原 紫外线吸收物质 UV-B辐射 

分 类 号：Q945.11[生物学—植物学]