桑属植物导管形态特征及其分类学意义

Characters of Vessel and Their Taxonomical Significance in Morus

借助光学显微镜系统观察了桑属(Morus.)8个品种,2年生枝木质部离析材料,研究发现导管分子类型、大小和穿孔板等基本特征,这些特征在桑属种间存在广泛差异,具有重要的分类学意义。依据导管、穿孔板类型的特征,可以将桑属植物分为二类:长穗桑、白桑、广东桑、华桑组成较原始类,山桑、蒙桑、鸡桑、川桑组成较进化类。从导管分子的显微特征推测:桑属植物演化水平由低到高依次为:长穗桑、白桑→广东桑、华桑→山桑→蒙桑、鸡桑、川桑。

Microsection of two-years-shoot xylem isolated of 8 species of Morus by Jeffery solution were observed that there are widely range of differences among the vessel type,vessel size and vessel perforation plate characters those have the important classification meanings. Morus can be divided into two groups based on the characters of vessel and perforation plate. The primal group includes M. wittiorum Hand Mazz,Morus alba Linn,M. atropurpurea Roxb,M. cathayana Hemsl. Evolutionary group includes M. bombycis Koidz,M. mongolica Schneid,M.australis Poir,M. notabillis Schneid. Ratiocination based on microscopic characteristics of the vessel was summered that the evolutionary level of Morus from low to high is M. wittiorum Hand Mazz、Morus alba Linn→M. atropurpurea Roxb、M. cathayana Hemsl→M. bombycis Koidz→M. mongolica Schneid,M. australis Poir,M. notabillis Schneid.