樟科琼楠属16种植物的叶表皮特征及其分类学意义

Leaf Epidermis Characteristics of 16 Species of Beilschmiedia (Lauraceae) and Their Taxonomic Significance

利用光学显微镜对樟科琼楠属16种代表植物的叶表皮特征进行了观察研究,结果表明琼楠属16种植物中除红毛琼楠叶表皮具单细胞毛外15种叶表皮无毛;气孔复合体仅分布在下表皮,都是平列型,即保卫细胞的长轴与两个副卫细胞的长轴平行;叶表皮细胞大致可分为多边形和不规则形两种类型,其垂周壁样式可以分为连珠状、波浪状、直线状、连珠-波浪状四种类型.基于叶显微形态,用SPSS系统对16种植物进行了聚类分析,大致可分为4个组,但除贵州琼楠(B.kweichowensis)、网脉琼楠(B.tsangii)和红毛琼楠(B.rufohirtella)外,其他13种可明显区分开.

The leaf cuticle of 16 species of Beilschmiedia(Lauraceae)was studied with the optical microscope.It is found that except for B.rufohirtella leaf,which has unicellular hair,15 of the 16 species of Beilschmiedia have no hair on their out layer;the stomatal complexes were only restricted to the lower epidermis and all of them are paracytic,the long axis of guard cells being parallel to that of subsidiary cells;the leaf epidermal cells are either irregular or polygonal in shape;and the cell vertical wall can be divided into four types:bead-like,wavy,linear,bead-wavy.The clustering analysis with the SPSS software indicates that16 plants of the genus roughly fall into 4 categories and 13 of them have visible difference except for B.kweichowensis,B.tsangii and B.rufohirtella.