中国伞形科矮泽芹属植物叶表皮形态特征的研究

Morphological Features of Leaf Epidermis of Chinese Chamaesium Species(Apiaceae)

利用光学显微镜、扫描电镜对伞形科矮泽芹属8种植物叶表皮形态进行观察与研究。结果表明:(1)矮泽芹属8种植物上下表皮细胞均为不规则形或规则多边形,垂周壁为近平直状或波状,上表皮细胞长宽比在1.3~2.4之间,下表皮细胞长宽比在1.5~2.5之间;在近轴面,有细叶矮泽芹、聂拉木矮泽芹和绿花矮泽芹3种植物没有气孔器的存在,其余物种气孔密度在20~74个/mm2之间,气孔指数为6.0%~17.7%;在远轴面,所有物种都具有丰富的气孔器,气孔密度为100~183个/mm2,气孔指数为16.1%~23.6%。(2)聚类分析结果显示,矮泽芹、大苞矮泽芹、粗棱矮泽芹为类群Ⅰ,鹤庆矮泽芹为类群Ⅱ,聂拉木矮泽芹、细叶矮泽芹、绿花矮泽芹为类群Ⅲ,松潘矮泽芹则单独聚为类群Ⅳ;聚类分析结果大体上支持形态学分类的结果。(3)叶表皮形态特征对于区分矮泽芹属不同物种具有十分重要的分类学价值。

The epidermal morphology of eight species of Chamaesium was observed by light microscope and scanning electron microscope.The results indicated that：（1）the epidermal cells of eight Chamaesiumspecies are irregular or regular polygon,with sinuolate and nearly straight anticlinal cells.The length to width ratio of upper epidermis cells was between 1.5-2.5.These were no stomatal in upper epidermis of three species,C.wolffianum,C.mallaeanum and C.viridiflorum.Stomatal density of other species was between 20-74/mm^2,and stomatal index was 6.0%-17.7%.In the lower epidermis,all eight species have plenty of stomata,the stomatal density was 100-183/mm^2,stomatal index was between16.1%-23.6%.（2）C.paradoxum,C.novemjugumand C.spatuliferum were clustered in the first group,C.delavayi was formed the second group,C.wolffianum,C.mallaeanumand C.viridiflorum belonged to the third group,while C.thalictrifolium formed an individual group by cluster analysis,which is almost accordance with the characteristics of leaf epidermis.（3）Characteristics of leaf epidermis play important roles in taxonomy of Chamaesium.