杉科植物枝/根木质部水分运输功能、机械强度与解剖结构的关系  

Relationships among water transport, mechanical strength and anatomical structure in branch and root xylem of Taxodiaceae species

作　　者：陈森 陆世通 李彦 谢江波 叶琳峰[1,2] 王忠媛 CHEN Sen;LU Shitong;LI Yan;XIE Jiangbo;YE Linfeng;WANG Zhongyuan(State Key Laboratory of Subtropical Silviculture,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China;College of Forestry and Biotechnology,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China;State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China)

机构地区：[1]浙江农林大学省部共建亚热带森林培育国家重点实验室,浙江杭州311300 [2]浙江农林大学林业与生物技术学院,浙江杭州311300 [3]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,新疆乌鲁木齐830011

出　　处：《浙江农林大学学报》2022年第2期233-243,共11页Journal of Zhejiang A&F University

基　　金：国家自然科学基金资助项目(31770651,41730638,31901280);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开放基金资助项目。

摘　　要：【目的】研究湿润地区杉科Taxodiaceae北美红杉Sequoia sempervirens、落羽杉Taxodium distichum、池杉T.distichum var.imbricatum木质部水分运输、解剖结构和机械强度的定量关系,探讨木质部解剖结构与功能在器官和物种水平的权衡。【方法】以浙江省天目山北美红杉、落羽杉、池杉为研究对象,用空气注入法测量3种植物枝/根的比导率(K_(s))和栓塞抗性(P_(50)),测量管胞壁厚度(T_(t))、纹孔膜面积(A_(pm))、纹孔口面积(A_(pa))、纹孔膜直径(P_(d))、纹孔口直径(A_(d))、水力直径(D_(h))、管胞密度(N_(t))、纹孔开口比((R_(ap)))、纹孔密度(N_(pm))等指标与水分运输有关的解剖结构,以及木质部密度(D_(w))、厚度跨度比(T_(tob))等与机械强度相关的指标,同时分析了水力功能与结构的关系。【结果】3种植物根的输水效率高于枝,栓塞抗性低于枝;北美红杉枝和根、落羽杉根以及池杉枝和根的K_(s)与P_(50)均为正相关,落羽杉枝的K_(s)与P_(50)有微弱的负相关,差异不显著(R^(2)=0.03,P=0.35),因此,3种植物在种内水平上没有效率-安全权衡;在跨物种间,K_(s)与P_(50)存在权衡,遵循指数为−2.23的负幂函数关系(R^(2)=0.91,P<0.001);北美红杉枝的K_(s)与D_(w)(R^(2)=0.37,P<0.01)、K_(s)与T_(tob)(R^(2)=0.20,P<0.01)、P_(50)与T_(tob)(R^(2)=0.20,P<0.01)均有显著的负相关关系。【结论】3种植物枝与根的木质部安全性和效率均较低,在种内水平上没有效率-安全权衡,这是因为3种植物对高安全性和高效率的结构需求不同,即效率-安全权衡的结构基础并不存在。[Objective]This study,with Sequoia sempervirens,Taxodium distichum and T.distichum var.imbricatum in humid regions selected as subjects,is aimed at an analysis of the quantitative relationships among the water transport,anatomical structure,and mechanical strength of the xylem of the branches and roots of the Taxodiaceae species and a discussion of the trade-off between the anatomy and function of the xylem at the organ and cross-species levels. [Method] Targeting the S. sempervirens, T. distichum and T. distichum var. imbricatum grown in Mount Tianmu, Zhejiang Province, with air injection method employed, efforts were made to measure the specific sapwood conductivity (K_(s)) and cavitation resistance (P_(50)) before the indexes regarding the water transport such as tracheid wall thickness (T_(t)), pit membrane area (A_(pm)), pit aperture area (A_(pa)), pit membrane diameter (P_(d)), pit aperture diameter (A_(d)), hydraulic diameter (D_(h))、tracheid density (N_(t)), aperture opening ratio (R_(ap)) and pit density (N_(pm)) were measured and calculated. Then, the wood density (D_(w)) and thickness-to-span ratio (T_(tob)) related to mechanical strength were calculated. Finally, an analysis was conducted of the correlation between water transport and anatomical structure. [Result] The roots demonstrated higher hydraulic conductivity yet weaker cavitation resistance than the branches and K_(s) in branches of S. sempervirens and T. distichum, and roots of S. sempervirens, T. distichum and T. distichum var. imbricatum was positively correlated with P_(50), while K_(s) in branches of T. distichum was slightly negatively correlated with P_(50) (R^(2)=0.03, P=0.35), showing no efficient-safety trade-off at the organ level. There was a trade-off between K_(s) and P_(50) across species, following a negative power function of −2.23 (R^(2)=0.91, P< 0.001). There was significant negative correlation between K_(s) and D_(w) (R^(2)=0.37, P< 0.01), K_(s) and T_(tob) (R^(2)=0.20, P< 0.01), P_(50) and T_(tob) (R^(2)=0.20, P<0.01

关 键 词：湿润区 北美红杉 落羽杉属 水力效率 栓塞抗性 效率-安全权衡 

分 类 号：S718.5[农业科学—林学]