3种树木节和节间导管接触角的研究

目的]探索导管在植物形态学及水分输导中的作用。方法]以白蜡、杜仲和五角枫为试材,以枝条为样本,对节和节间木质部的导管进行解剖,在复水处理的条件下测定接触角。结果]节和节间木质部导管特征明显不同,节间导管较为均一,基本上为大导管,小导管数量极少,且节间细胞多为分化细胞,呈长柱状,细胞排列方向确定。构成节的细胞不均一,小导管较多,导管迂回盘绕,节区细胞分化程度也不均一,有的细胞仍处于分化阶段,原生质浓厚,细胞排列方向不规则。接触角的大小明显不同,节间的接触角均大于节的接触角。结论]节区导管对水分具有更强的拉伸作用,节在植物体水分运输的过程中具有重要作用。

Study on Dissection Structure and Contact Angle of Vessels between Nodes and Internodes in Three Kinds of Trees

Objective] The study aimed to explore the action of vessels on plant morphologic and water conduction.Method] With Fraxinus pennsylvanica,Eucommia ulmoides and Acer mono Maxim as tested materials and their branches as samples,the xylem vessels of nodes and internodes were anatomized and the contact angles were measured under the condition of rehydration.Result] The xylem vessels character between nodes and internodes were significantly different.Vessels in internodes were uniform relatively,most were big vessels and less were small the vessels.Most cells in internodes were already differentiated,like long pillar and ranged determinately,whereas the cells composing nodes were un-uniform,there were more small vessels which were circuitously.Differentiation degree of cells in nodes were also un-uniform,some were still differentiating with dense protoplasm and ranged un-orderly.The size of contact angle were different evidently and the contact angles of internodes were bigger than that of nodes.Conclusion] The vessels in node section played an even stronger pulling role in water conducting and the nodes played an important role in water transportation.