西洋参叶片光合作用对干旱胁迫的响应机制  

Response Mechanisms of Photosynthesis of Leaves of Xiyangshen(Panax Quinquefolium Radix)to Drought Stress

作　　者：林莺[1,2] 王玲娜[1] 张江平[2] 李佳 刘谦[1] 王少平[2] 耿子凯 周洁 张永清[1] LIN Ying;WANG Lingna;ZHANG Jiangping;LI Jia;LIU Qian;WANG Shaoping;GENG Zikai;ZHOU Jie;ZHANG Yongqing(Shandong University of Traditional Chinese Medicine,Jinan 250355,China;Binzhou Medical University,Yantai 264003,China;University of Jinan,Jinan 250022,China)

机构地区：[1]山东中医药大学,山东济南250355 [2]滨州医学院,山东烟台264003 [3]济南大学,山东济南250022

出　　处：《山东中医药大学学报》2022年第2期252-259,共8页Journal of Shandong University of Traditional Chinese Medicine

基　　金：山东省重点研发计划项目(编号:2016CYJS08A01);山东省中医药科技发展计划项目(编号:2017-227,2019-1021)。

摘　　要：目的:研究西洋参植株叶片光合作用对干旱胁迫的响应机制,为栽培生产水分管理提供理论依据。方法:盆栽模拟干旱胁迫,每隔2 d,便携式光合仪测定不同光强下叶片净光合速率(Pn)和气体交换参数[气孔导度(gs)、胞间CO2浓度(Ci)],模拟计算光饱和点(LSP)与光补偿点(LCP),植物效率仪测定叶绿素荧光参数。结果:自干旱胁迫模拟起至第2天(土壤相对含水量分别为80.0%、66.8%)各指标差异无统计学意义(P>0.05)。随干旱胁迫加重,LSP、Pn、gs降低,LCP、Ci升高;电子传递量子产额(ETO/CSM)随干旱胁迫加重先降低后升高,转折点在第10天;Pn、Ci和gs在第4天同时下降。结论:西洋参植株具有一定耐旱性,可通过关闭气孔或提高光系统Ⅱ(PSⅡ)反应中心电子传递,调整植株对光能的利用以分别应对轻度和重度干旱胁迫,长期重度干旱胁迫会破坏叶片光合机构、降低Pn及植株根重。生产中维持土壤相对含水量在66.8%~80.0%,可保证西洋参植株叶片光合作用的正常进行。Objective:To study the response mechanism of photosynthesis of leaves of Xiyangshen(Panax Quinquefolium Radix)to drought stress,and provide theoretical basis for water management in cultivation of Xiyangshen.Methods:Net photosynthetic rate(Pn)and gas exchange parameters of leaves of Xiyangshen(stomatal conductance gs and intercellular CO2 concentration C1)under different light intensities were measured by portable photosynthetic instrument every 2 days with a pot experiment simulating drought stress.The light saturation point(LSP)and light compensation point(LCP)were simulated and calculated.Chlorophyll fluorescence parameters were measured by Handy-PEA.Results:There was no significant difference in the photosynthetic indexes of the leaves of Xiyangshen from the day of drought stress simulation to the second day(soil relative water content was 80.0%and 66.8%,respectively)(P>0.05).With the increase of drought stress,LSP,Pn,gs decreased,LCP and Ci increased.The electron transfer quantum yield(ETO/CSM)decreased first and then increased with the increase of drought stress,the turning point was on the 10th day.Pn,Ci and gs decreased at the same time on the fourth day.Conclusions:The plants of Xiyangshen have certain drought tolerance,which can adjust the utilization of light energy by closing stomata or improving electron transfer of photosystemⅡ(PSⅡ)reaction center to cope with mild and severe drought stress respectively.But the long-term severe drought stress will eventually damage the photosynthetic apparatus of the leaves of Xiyangshen,and reduce Pn and weight of root.Therefore,the relative water content of soil should be kept in the range of 66.8%~80.0%in order to ensure the normal photosynthesis of Xiyangshen leaves.

关 键 词：西洋参 干旱胁迫 光合作用 光饱和点 光补偿点 响应机制 

分 类 号：R282.71[医药卫生—中药学]