CO2加富对施盐处理下银叶树幼苗叶片光合特性的影响  

Effect of CO2 enrichment on photosynthetic characteristics in the leaves of Heritiera littoralis seedlings under salinity treatment

作　　者：肖石红 张卫强[1] 黄芳芳[1] 甘先华[1] 蔡坚[1] 朱子维 XIAO Shihong;ZHANG Weiqiang;HUANG Fangfang;GAN Xianhua;CAI Jian;ZHU Ziwei(Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization/Guangdong Academy of Forestry, 510520, Guangzhou, China)

机构地区：[1]广东省森林培育与保护利用重点实验室/广东省林业科学研究院,广州510520

出　　处：《中国水土保持科学》2020年第5期127-135,共9页Science of Soil and Water Conservation

基　　金：广东东江源森林生态系统国家定位观测研究站运行补助(2019132072);广东省林业科技创新项目“风电建设对森林生态系统的影响评价”(2019KJCX010)。

摘　　要：为明确大气CO2浓度升高对施盐处理下银叶树光合特性的影响,利用LI6800便携式光合测定仪测定施盐处理60 d后银叶树幼苗叶片在不同CO2浓度(400、600和800μmol/mol)下对光的响应曲线以及CO2响应曲线。结果表明:1)随着CO2浓度的升高,银叶树幼苗叶片净光合速率(Pn)、最大净光合速率(Pnmax)、表观量子利用效率(AQY)、光饱和点(LSP)、暗呼吸速率(Rd)、水分利用效率(WUE)和胞间CO2浓度(Ci)均呈上升趋势,而光补偿点(LCP)、蒸腾速率(Tr)和气孔导度(Gs)则呈下降趋势;2)同一CO2浓度下,施盐处理下银叶树幼苗叶片Pn、Pnmax、AQY、LSP、LCP、Rd、Tr和Gs均低于对照处理,而WUE和Ci则差异不大;3)随着光合有效辐射(PAR)的增加,银叶树幼苗叶片Tr和Gs呈增加的趋势,WUE先增加后缓慢减小,Ci则先直线下降,之后达到稳定状态;4)施盐处理下银叶树幼苗叶片最大羧化速率(Vcmax)、最大电子传递速率(Jmax)、磷酸丙糖利用效率(TPU)、Pnmax、初始羧化效率(CE)和光呼吸速率(RP)均低于对照处理,而CO2饱和点(Cisat)和CO2补偿点(Γ)则更高;5)随着CO2浓度的增加,银叶树幼苗叶片Tr和Gs大致呈下降的趋势,WUE和Ci则呈直线增加的趋势。本研究结果说明CO2浓度的增加对银叶树幼苗的生长有促进作用,而施盐处理则抑制其生长。[Background]Heritiera littoralis is an endangered semi mangrove tree species.Recently,the community structure,biological characteristics,medicinal value,fruit characteristics and germination technology and genetic diversity of H.littoralis have mainly been analyzed by scholars,but the high CO2 concentration on photosynthetic characteristics in the leaves of H.littoralis seedlings under salinity treatment has been less investigated.It is important to explore the effects of elevated CO2 on photosynthesis characteristics in H.littoralis under salinity treatment,which is essential to provide references for the application of H.littoralis to the vegetation restoration in coastal areas.[Methods]1-year-old H.littoralis seedlings were used for comparison test in the green house of Guangdong Academy of Forestry in Guangzhou.Salinity treatment was simulated using salt solution concentration gradients of 0(CK)and 2.5%(salinity treatment)at different CO2 concentration(400,600 and 800μmol/mol).There were 16 repeats in each concentration,thus totally 96 pots.After 60 days,photosynthetic physiological parameters were measured by LI-6800 photosynthesis instrument(LI-COR,USA).Then modified rectangular hyperbolic model was adopted to fit the photosynthesis light-response curves at different CO2 concentration and CO2 response curves of H.littoralis leaves of salinity treatment.[Results]1)After the experiment treatment,with the increase of CO2 concentration,net photosynthetic rate(Pn),maximum net photosynthetic rate(Pnmax),apparent quantum yield(AQY),light saturation point(LSP),dark respiration rate(Rd),water use efficiency(WUE)and intercellular CO2 concentration(Ci)in the leaves of H.littoralis seedlings increased,while light compensation point(LCP),transpiration rate(Tr)and stomatal conductance(Gs)decreased.2)At the same CO2 concentration,Pn,Pnmax,AQY,LSP,LCP,Rd,Tr and Gs under salinity treatment were lower than those under control,while the difference of WUE and Ci between the two treatment groups were not significant.3)With the

关 键 词：银叶树 施盐处理 CO2加富 光合特性 

分 类 号：S718.43[农业科学—林学]