干旱胁迫下乔木状沙拐枣枝干光合作用对水力性状与叶片光合作用的影响  

Effects of stem photosynthesis on hydraulic traits and leaf photosynthesis in Calligonum arborescens under drought stress

作　　者：李民青 周孝明 王双龙 陈丽丹 李从娟 刘冉[1,2] LI Min-Qing;ZHOU Xiao-Ming;WANG Shuang-Long;CHEN Li-Dan;LI Cong-Juan;LIU Ran(Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,State Key Laboratory of Desert and Oasis Ecology,Ürümqi 830011,China;National Field Scientific Observation and Research Station of Desert Ecology,Chinese Academy of Sciences,Fukang,Xinjiang 831505,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Geography and Remote Sensing Sciences,Xinjiang University,Ürümqi 830046,China;College of Life Sciences,Shihezi University,Shihezi,Xinjiang 832003,China;National Engineering Technology Research Center for Desert-Oasis Ecological Construction,Ürümqi 830011,China)

机构地区：[1]中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,乌鲁木齐830011 [2]中国科学院阜康荒漠生态国家野外科学观测研究站,新疆阜康831505 [3]中国科学院大学,北京100049 [4]新疆大学地理与遥感学院,乌鲁木齐830046 [5]石河子大学生命科学学院,新疆石河子832003 [6]国家荒漠-绿洲生态建设工程技术研究中心,乌鲁木齐830011

出　　处：《植物生态学报》2024年第11期1524-1535,共12页Chinese Journal of Plant Ecology

基　　金：新疆维吾尔自治区天山英才(2022TSYCCX0002);新疆维吾尔自治区杰出青年(2023D01E19);中国科学院西部之光(2020-XBQNXZ-013和2021-XBQNXZ-002)。

摘　　要：枝干光合作用是维持植物碳平衡不可忽视的重要部分,探究荒漠木本植物枝干光合在干旱胁迫下的响应机制有助于深入理解荒漠植物抵抗干旱的能力。该研究采用盆栽控制实验,以两年生乔木状沙拐枣(Calligonum arborescens)幼苗为研究对象,遮光组用铝箔对幼苗枝干进行遮光处理(无枝干光合),对照组枝干维持正常光照(有枝干光合),在干旱初始、干旱15天与30天后测定两组植物枝干和叶片光合特征、水力性状以及非结构性碳水化合物(NSC)含量等参数。结果表明:(1)乔木状沙拐枣的枝干光合平均速率为1.0-2.0μmol·m^(-2)·s^(-1),且未受干旱时间延长的影响,在干旱初始、干旱15天和干旱30天的枝干光合速率均值分别为1.42、1.28和1.21μmol·m^(-2)·s^(-1);干旱30天后枝干释放CO_(2)速率显著降低,枝干光合减少枝干释放CO_(2)比例显著提高;(2)随着干旱持续,幼苗的边材比导率、叶片/枝干含水量、水势以及叶片光合速率均显著降低,但是存在枝干光合的幼苗的下降趋势更为缓慢;(3)与遮光组相比,干旱15天后枝干光合显著降低木质部导度损失率,且显著增加叶片和枝干NSC含量;干旱30天后枝干光合显著减少了木质部栓塞导管数量与横截面积比例,分别减少33.8%和22.8%;(4)同时期对照组的幼苗叶片光合速率均显著高于遮光组,在干旱15天和30天后分别高2.3和3.2μmol·m^(-2)·s^(-1)。研究结果表明,枝干光合能够提高乔木状沙拐枣栓塞抵抗力,同时对NSC储存以及叶片气体交换均有显著影响。该文为深入理解荒漠木本植物干旱适应策略与生存机制提供理论基础。Aims Stem photosynthesis plays a crucial role in maintaining the carbon balance in plants.By exploring the impact of stem photosynthesis on hydraulic traits and leaf gas exchange in desert woody plants during a long period of drought,we aimed to gain deeper insights into the remarkable drought resistance capabilities of these plants in extreme environments.Methods Aluminum foil was used to shade the stems of two-year-old Calligonum arborescensseedlings planted in 15-L pots at the beginning of the 2022 growing season under the rain shelter of Fukang desert station.The stems of a control group were exposed to normal light levels.After 0,15 and 30 d of drought,the stem/leaf photosynthesis rate,hydraulic parameters,and non-structural carbohydrates(NSC)contents were measured in the shading and control groups.Important findings Our main results showed that:(1)Stem photosynthetic rate of C.arborescens ranged from 1.0 to 2.0μmol·m^(-2)·s^(-1),and was not significantly affected by the duration of the drought.Stem photosynthetic rates were 1.42,1.28 and 1.21μmol·m^(-2)·s^(-1)after 0,15 and 30 d of drought,respectively.(2)The specific hydraulic conductivity,leaf/stem water content,leaf water potential,and leaf photosynthetic rate decreased significantly over the dry period in the shading group but declined more slowly in the control group.(3)After 15 d without water,the percentage loss of conductivity,was significantly reduced in the control seedlings and the NSC contents of leaf and stem were significantly increased.Following 30 d of drought,the number and cross-sectional area of embolized vessels decreased significantly,by 33.8%and 22.8%,respectively,in the control seedlings.(4)In the same drought duration,leaf photosynthetic rate in the control group was significantly higher than that of the shading group,increasing 2.3 and 3.2μmol·m^(-2)·s^(-1)after 15 and 30 d of drought,respectively.Our results indicate that stem photosynthesis can improve the drought resistance of desert plants and provide a theoretical foun

关 键 词：枝干光合 非结构性碳水化合物 导度损失率 显微计算机断层扫描 叶片光合 

分 类 号：S43[农业科学—农业昆虫与害虫防治]