21种中国荚蒾属植物叶表皮微形态特征研究

Study on Leaf Micro-morphological Characteristics of 21 Species of Viburnum(Adoxaceae)in China

为解决荚蒾属植物分类学问题并探究叶片解剖结构在分类学中的价值,该研究利用光学显微镜和扫描电子显微镜对21种中国荚蒾属植物的叶表皮细胞、气孔大小、气孔器类型和角质层纹饰等叶表皮微形态特征进行了观察和比较,为荚蒾属种间分类关系提供证据。结果显示,叶表皮细胞有无规则形和多边形2种,垂周壁式样有平直、浅波状、波状与深波状4种式样,其中下表皮细胞形状均为不规则形,且垂周壁式样较上表皮更稳定。气孔均分布在下表皮,形状为近圆形、椭圆形2种;气孔器类型包括不等型、平列型和无规则型3种;气孔器外拱盖内缘有近平滑、浅波状、波状3种;气孔器外围角质层纹饰有脊状隆起、条状隆起2种。研究表明,荚蒾属植物叶表皮细胞和气孔器特征在种间差异明显,可作为种间鉴定及分类的重要依据,具有重要的分类学意义。

To address the taxonomic issues of Viburnum and explore the value of leaf anatomical structure in taxonomy,this study uses micro-morphological characters of 21 species of Viburnum in China,including shape of leaf epidermis,size of stomata,type and cortical ornamentation of stomatal apparatus,and so on,was observed and measured under light microscope(LM)and scanning electron microscope(SEM),which provide foundation for phylogenetic study of Viburnum.The results show that there are 2 kinds of leaf epidermal cells classified as irregular and polygonal shapes,and 4 patterns of anticlinal wall,i.e.,straight,sinuolate,undulate or sinuate,among which the shape of the abaxial epidermal cells was irregular,and the anticlinal wall pattern is more stable than those of the adaxial epidermal.In addition,the stomata were only distributed in the abaxial epidermal,with its shape being nearly round and oval.The types of the stomatal apparatus were anisocytic,paracytic and anomocyitc.Three kinds of inner edge of the outer arch cover of the stomatal apparatus,i.e.,nearly smooth,sinuolate or undulate.Two shapes of stratum corneum on the periphery of the stomatal apparatus were observed,i.e.,with ridge hunch,striped hunch.This study indicates that the characters of leaf epidermal cells and stomatal apparatus of Viburnum are different to a large extent,which can be served as one of the criteria to identify and classify species of Viburnum.The taxonomic significance of these micro-morphological traits in Viburnum was discussed in this paper.