27种木犀属植物叶表皮微形态特征的研究

利用光学显微镜和扫描电子显微镜观察了27种木犀属植物的叶表皮,测量并统计了气孔器类型、气孔大小、气孔密度、气孔指数及腺点密度等指标,以明确各种的叶表皮细胞形状及垂周壁式样、表皮角质膜、蜡质纹饰及气孔外拱盖的具体特征。结果显示:木犀属植物叶下表皮有气孔器,形状为圆形、椭圆形;气孔器类型多为不规则型,只有总状桂花和狭叶木犀为环列型;气孔器外围角质层有放射状、条状、环状、颗粒状等多种类型;叶表皮细胞形状有无规则形和多边形2种;下表皮腺点的数目远远大于上表皮。研究表明,木犀属植物气孔器和叶表皮细胞特征在种之间差异比较明显,可以作为种间鉴定的重要依据,具有重要的分类学意义。

Study on Leaf Micro-morphological Characteristics of Osmanthus(Oleaceae)

The leaf epidermis structures of 27 species,which belong to Osmanthus have been examined under LM and SEM.The stomatal size,stomatal density,stomatal index and gland density,shape and pattern of anticlinal walls of epidermis cells were measured and counted under LM.Under SEM,it was described such as the shape of stomata,cuticular membrane,wax ornamentation,outer stomatal rim.The results showed that only the abaxial epidermal had stomata.The shapes of the stoma were round and oval.The type of stomatal apparatuses in Osmanthus were mostly anomocytic and those of only two species O.racemosus and O.attenuatus always cyclocytic.The cuticular membrane periphery of stomatal apparatus was radial,strip,ring and granulated.The shapes of leaf epidermal cells in Osmanthus were usually irregular or polygonal.The number of gland in abaxial epidermal was larger than that of adaxial epidermal.The characters of stomatal apparatuse and leaf epidermal cells in Osmanthus were different in a large degree.These different micromorphological characters could serve as one of the criteria to identify species of Osmanthus.The taxonomic significance of these characters in Osmanthus was discussed in the paper.