冬青属植物的叶表皮特征及其分类学意义

Epidermal anatomy of the genus Ilex and its taxonomic significance

利用光学显微镜对102种冬青属植物的叶表皮特征进行了观察.结果表明:不同种冬青属植物的叶表皮特征既具有一定的相似性(如气孔器下生),据大小可分为正常气孔器和大气孔器,气孔器类型以双环列型为主,其次为环列型、三环列型和辐射型,下表皮具有退化大气孔器、簇状木质化细胞和瘿状结构;也具有一定的差异性,如叶表皮细胞的大小、形状、垂周壁形态和表面纹饰以及表皮毛的有无和长度.冬青属叶表皮特征的共同点表明冬青属是一自然类群,而其不同点说明叶表皮的某些特征可以作为种间分类的依据.因此,冬青属的叶表皮特征具有分类学意义,能为该属现生植物的系统分类、化石植物鉴定和系统演化研究提供可靠的证据.

Foliar cuticles of 102 species of Ilex were examined under a light microscope. The results show that cuticle features are uniform to some extent at an inter-specific level： leaves being hypostomatic with normal and giant stomata, the stomatal type primarily comprising amphicyclocytic, secondly cyclocytic, tricyclic and actinocytic, abaxial epidermis with regressive/aberrant giant stomata, lignified cells and wart-like structures. But some cuticular variability exists at an inter-specific level in terms of cell size, shape, anticlines, surface ornamentations and trichomes. Therefore, the common cuticular features indicate that the genus Ilex is a natural taxon, while the minor variations in its epidermal anatomy provide additional evidence for the inter-specific differentiation. It is concluded that the epidermal anatomy of Ilex is of considerable taxonomic significance, having great potential to improve the classical taxonomy, paleobotany and phylogenetics.