水淹胁迫对桢楠幼树生长及光合生理特性的影响  

Effects of Flooding Stress on Growth and Photosynthetic Physiological Traits of Phoebe zhennan Saplings

作　　者：陈玉凤[1] 谭飞[1,2] 胡红玲 胡庭兴[1] 喻秀艳[1] 周鑫 杨珊珊[1] 张成浩[1] 张建 CHEN Yu-feng;TAN Fei;HU Hong-ling;HU Ting-xing;YU Xiu-yan;ZHOU Xin;YANG Shan-shan;ZHANG Cheng-hao;ZHANG Jian(College of Forestry,Sichuan Agricultural University,Chengdu 611130,China;Liangshan Forestry Survey and Planning Institute,Xichang 615000,China)

机构地区：[1]四川农业大学林学院,四川成都611130 [2]四川省凉山州林业调查规划设计院,四川西昌615000

出　　处：《生态与农村环境学报》2018年第3期224-231,共8页Journal of Ecology and Rural Environment

基　　金：四川省"十三五"农作物育种公关项目(2016NZ0098-10);四川省教育厅重点项目(13ZA0246)

摘　　要：以2.5 a生桢楠(Phoebe zhennan)幼树为材料,采用套盆水淹法,分别对桢楠幼树(每组5株)进行不同时段(0、7、14、21、28和35 d)的水淹胁迫处理,测定各处理桢楠幼树的生长及光合生理指标,探讨桢楠幼树生长及光合生理对水淹胁迫的响应,旨在为桢楠幼树的培育及其人工林科学的水分管理提供理论依据。结果显示:(1)水淹胁迫显著抑制桢楠幼树的生长,而地径增量先升后降,且不同水淹时间下株高净生长量分别比对照下降43.4%、59.2%、59.2%和80.8%,水淹35 d的植株全部死亡;(2)水淹胁迫改变了桢楠幼树叶绿体色素的含量和比值,随着水淹胁迫时间的延长,各处理叶绿素a(Chl a)含量分别比对照下降17.4%、22.0%、38.4%和52.3%,类胡萝卜素/叶绿素比值表现为先升后降;(3)叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均随着胁迫时间的延长显著降低,胁迫28 d时其下降幅度分别为对照的89.6%、98.2%和98.7%;胞间CO_2浓度(Ci)则显著增加,其增加幅度达216.2%;(4)叶片最大净光合速率(Pn,max)和光饱和点(Lsp)显著下降,而光补偿点(Lcp)和CO_2补偿点(Ccp)显著上升,叶片净光合速率受到显著抑制。综上,水淹胁迫显著影响桢楠幼树叶片气体交换和光合速率,使其对光照和CO_2的利用能力降低,光合能力受到影响,表现出不耐水淹的生理生态特性,胁迫28 d时大部分植株萎焉濒临死亡,35 d时受胁迫植株全部死亡。To study effects of flooding on growth and photosynthetic physiology of Phoebe zhennan saplings and provide certain theoretical basis for cultivation and water management of P.zhennan saplings,a pot experiment was conducted with the pots planted with 2.5 year-old P.zhennan saplings and flooded.The experiment was designed to have 6 groups or treatments,5 saplings each,for duration of flooding,i.e.0(CK),7,14,21,28 and 35 days.Growth and photosynthetic indexes of the P.zhennan saplings in all the treatments were monitored.Results show:(1)Flooding significantly inhibited growth of the plants,though basal diameter of the plants increased first and then decreased in all the treatments.Net plant height decreased by 43.4%,59.2%,59.2%and 80.8%in Treatment 7D,14D,21D and 28D,respectively,as compared with CK(0 d),and the plants in Treatment 35D failed to survive;(2)Flooding altered the content and ratio of chloroplast pigments of P zhennan saplings in all the treatments,the contents of chlorophyll a(Chl a)decreased by 17.4%,22.0%,38.4%and 52.3%,respectively,while carotenoids/chlorophyll ratio increased by 32.3%,71.0%,32.3%and 45.2%,respectively in Treatment 7D,14D,21D and 28D,showing a trend of rising first and then declining;(3)Net photosynthetic rate(P n),transpiration rate(T r)and stomatal conductance(G s)were declining significantly with the stress going on and,decreased by 89.6%,98.2%and 98.7%,respectively in Treatment 28D.However,the concentration of carbon dioxide(C i)between cells significantly increased by 216.2%in Treatment 28D;And(4)in the plants under stress,light compensation point(L cp)and CO 2 compensation point(C cp)showed an increasing trend,while the max net photosynthetic rate(P n,max)and light saturation point(L sp)decreased dramaticly.In conclusion,P.zhennan saplings exhibited showed low resistance to flooding stress,which significantly inhibited air exchange and photosynthetic rate and weakened the plants′ability to make use of light and CO 2,and hence their photosynthetic capacity.In the experiment,

关 键 词：水淹胁迫 桢楠幼树 叶绿素 光合生理 生长 

分 类 号：Q945[生物学—植物学]