干旱程度对C_3植物红砂和C_4植物珍珠光合生理参数的影响  

Response of Photosynthetic Characteristics of C_3 Desert Plant Reaumuria soongorica and C_4 Desert Plant Salsola passerina to Different Drought Degrees

作　　者：严巧娣[1,2] 苏培玺[1] 高松[1,2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所临泽内陆河流域研究站/植物逆境生理生态与生物技术实验室,甘肃兰州730000 [2]台州学院生态研究所,浙江临海317000

出　　处：《中国沙漠》2012年第2期364-371,共8页Journal of Desert Research

基　　金：国家自然科学基金项目(91025026;31070359);中国科学院西部行动计划项目(KZCX2-XB2-09-03;KZCX2-XB2-04-01)共同资助

摘　　要：C3和C4植物混生在草地生态系统中较多,而在荒漠生态系统少见。在中国荒漠地区,C3小灌木红砂和C4半灌木珍珠在特定生境下混生在一起,以独特方式适应高温强光和干旱的极端环境。通过在不同干旱程度下测定它们生长期叶片的光合气体交换参数,探讨它们在混生条件下对极端环境的生理响应特征。结果表明,红砂的净光合速率(Pn)、蒸腾速率(E)、气孔导度(Gs)均要高于珍珠;而珍珠的水分利用效率(WUE)则要高于红砂。这表明珍珠和红砂在水分匮乏的荒漠生境下采取了不同的生存策略。红砂通过维持较高净光合速率和较高蒸腾速率来生存;而珍珠则通过高水分利用效率生存。The mixed community of C3 and C4 plants is easily seen in grassland ecosystem,but hardly seen in desert ecosystem.In desert regions of China,some C3 and C4 shrubs coexist in particular manners in some specific habitats and adapt to the extreme arid environment,which is associated with high temperature and intensive radiation.The mixed communities of C3 undershrub Reaumuria soongorica and C4 subshrub Salsola passerina in the Heihe River Basin in Hexi Corridor were investigated.The physiological characteristics of gas exchange of R.soongorica and S.passerina in the mixed community were determined under different drought degrees.Results showed that net photosynthetic rate(Pn),transpiration rate(E),stomatal conductance(Gs) of R.soongorica were all higher than S.passerina,while water use efficiency of S.passerina was higher than R.soongorica.The differential responses of the two species to severe habitat shows that R.soongorica and S.passerina take different strategies for survival when suffering water scarcity in the same desert habitats: R.soongorica uses the means of maintaining a higher net photosynthetic rate and a higher transpiration rate to survive,while S.passerina survives here through the higher water use efficiency.

关 键 词：红砂 珍珠猪毛菜 共存 气体交换 干旱适应策略 

分 类 号：Q915[天文地球—古生物学与地层学]