6个耐旱树种木质部结构与栓塞脆弱性的关系  

Relationships between xylem structure and embolism vulnerability in six species of drought tolerance trees

作　　者：李荣[1] 党维[1] 蔡靖[1,2] 张硕新[1,2] 姜在民[3] 

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100 [2]陕西秦岭森林生态系统国家野外科学观测研究站,陕西杨凌712100 [3]西北农林科技大学生命科学学院,陕西杨凌712100

出　　处：《植物生态学报》2016年第3期255-263,共9页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31270646)

摘　　要：木质部栓塞脆弱性对干旱响应的研究已成为全球气候变化背景下的热点和重要内容。该文以6个耐旱树种刺槐(Robinia pseudoacacia)、沙棘(Hippophae rhamnoides)、榆树(Ulmus pumila)、元宝枫(Acer truncatum)、旱柳(Salix matsudana)、榛(Corylus heterophylla)为研究对象,采用Cochard Cavitron离心机技术建立木质部栓塞脆弱曲线,计算木质部栓塞脆弱性,利用染色法、硅胶注射法等测定木质部导管直径、导管内径跨度、导管连接度、导管密度、导管长度和木质部密度,探究木质部结构与栓塞脆弱性的关系,区分6个耐旱树种木质部结构在抗栓塞性上的差异,以期建立6个耐旱树种在木质部结构方面的抗栓塞性指标。结果表明:6个耐旱树种木质部栓塞脆弱性大小为刺槐>榆树>沙棘>旱柳>元宝枫>榛,其中,刺槐、沙棘和榆树的栓塞脆弱曲线为"r"形,而元宝枫、旱柳和榛的栓塞脆弱曲线为"s"形,脆弱曲线为"r"形的树种与脆弱曲线为"s"形的树种栓塞脆弱性差异极显著(p<0.01)。线性分析表明:木质部结构影响各树种的栓塞脆弱性,其中,木质部密度影响最大(t=0.702),导管直径次之(t=0.532),导管长度影响最小(t=0.010)。Aims The study of embolism vulnerability to drought has become a hot and key topic under global climate change. The objective of the study was： 1） to identify the relationship between xylem structure and embolism vulnerability; 2） to define the differences in resistance of embolism in xylem structure of each species; and 3） to establish drought tolerance indexes in xylem structure of six species. Methods Drought tolerance trees of Robinia pseudoacacia, Hippophae rhamnoides, Ulmus pumila, Corylus heterophylla, Salix matsudana, Acer truncatum were studied. Cochard Cavitron centrifuge was used to establish embolism vulnerability curves and to calculate xylem vulnerability value. Staining and silicone injection tech- niques were used to to measure xylem structure of drought tolerance trees including vessel diameter, conduit wall span, number of vessels per unit area, contact faction, vessel length and wood density. Important findings The results showed： 1） xylem embolism vulnerability of the six species ranked as Robinia pseudoacacia 〉 Ulmus pumila 〉 Hippophae rhamnoides 〉 Salix matsudana 〉 Acer truncatum 〉 Corylus heter- ophylla; 2） the vulnerability curves is ＂r＂ shape for Robinia pseudoacacia, Hippophae rhamnoides, Ulmus pumila and is ＂s＂ shape for Corylus heterophylla, Salix matsudana, Acer truncatum, respectively; 3） the xylem vulner- ability values is significantly different in trees of ＂r＂ shape and ＂s＂ shape （p 〈 0.01）. Furthermore, linear analysis showed that the different effects between the xylem structure of the species was closely related to the vulnerability in the following order： the maximum effect was from wood density （t = 0.702）, the medium effect was from vessel diameter （t = 0.532）, and the minimum effect was from vessel length （t = 0.01）.

关 键 词：栓塞脆弱性 栓塞脆弱曲线 木质部结构 耐旱树种 

分 类 号：S718.4[农业科学—林学]