土壤水分胁迫和大气CO2浓度对光合分馏及后光合分馏的影响  

Effects of soil water stress and atmospheric CO2 concentration on photosynthetic and post-photosynthetic fractionation

作　　者：丁兵兵 张永娥 余新晓[1] 贾国栋[1] 王渝淞 郑鹏飞 蒋涛 夏娟娟 DING Bing-bing;ZHANG Yong-e;YU Xin-xiao;JIA Guo-dong;WANG Yu-song;ZHENG Peng-fei;JIANG Tao;XIA Juan-juan(Ministry of Educa-tion Key Laboratory of Soil and Water Conservation and Desertification Combating,Beijing Forestry University,Beijing 100083,China;Institute of Sediment Research,China Institute of Water Resources and Hydropower Research,Beijing 100038,China).)

机构地区：[1]北京林业大学水土保持与荒漠化防治教育部重点实验室,北京100083 [2]中国水利水电科学研究院泥沙研究所,北京100038

出　　处：《应用生态学报》2020年第6期1800-1806,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金重点项目(41877152)资助。

摘　　要：对植物光合和后光合分馏进行分析,有助于提升对植物生理和水分管理等的认识。本研究通过测定大气、侧柏叶片和枝条韧皮部可溶性化合物的δ13C,探讨了光合作用时大气和叶片间碳同位素的分馏(ΔCa-leaf)和光合作用后叶片到枝条间的碳同位素分馏(ΔC_(leaf-phlo))对土壤含水量(SWC)和大气CO2浓度(C_a)的响应。结果表明:ΔCa-leaf在SWC为田间持水量(FC)的95%~100%(95%~100%FC)且C_a为400μmol·mol^-1时达到最大值(13.06‰),在SWC为35%~45%FC且C_a为800μmol·mol^-1时达到最小值(8.63‰);气孔导度和叶肉细胞导度均与ΔCa-leaf呈显著线性正相关,相关系数分别为0.43和0.44;而ΔC_(leaf-phlo)并未受到SWC和C_a的显著影响。本研究不仅可以提高对碳同位素的分馏机制的认识,而且可以为植物对未来气候变化的生存适应性提供理论依据。Analysis of plant photosynthesis and post-photosynthetic fractionation can improve our understanding of plant physiology and water management.By measuringδ13C in the atmosphere,andδ13C of soluble compounds in leaves and branch phloem of Platycladus orientalis,we examined discrimination pattern,including atmosphere-leaf discrimination during photosynthesis(ΔCa-leaf)and leaf-twig discrimination during post-photosynthesis(ΔCleaf-phlo),in response to changes of soil water content(SWC)and atmospheric CO2 concentration(Ca).The results showed thatΔCa-leaf reached a maximum of 13.06‰at 95%-100%field water-holding capacity(FC)and Ca 400μmol·mol-1,and a minimum of 8.63‰at 35%-45%FC and Ca 800μmol·mol-1.Both stomatal conductance and mesophyll cell conductance showed a significant linear positive correlation withΔCa-leaf,with a correlation coefficient of 0.43 and 0.44,respectively.ΔCleaf-phlo was not affected by SWC and Ca.Our results provide mechanism of carbon isotopes fractionation and a theoretical basis for plant survival strategies in response to future climate change.

关 键 词：土壤含水量 CO2浓度 碳同位素 光合分馏 后光合分馏 

分 类 号：Q945[生物学—植物学]