桫椤科2属6种植物叶表皮微形态特征及其分类学意义

The Leaf Epidermis Micromorphological Observation and Its Taxonomic Significance of Six Species of Two Genera in Cyatheaceae in China

利用扫描电子显微镜对桫椤科2属6种叶表面角质膜纹饰、表皮毛、气孔器类型、气孔器大小等叶表皮微形态特征进行观察和比较,探讨其分类学意义,编制供试2属6种分类检索表。结果表明:2属6种叶表皮表面角质膜纹饰均为脊状,气孔器大小无显著差异,气孔器类型均为平列型。表皮毛共有4种(囊状毛、片状毛、须状毛、盾状鳞),种间表皮毛差异较大,其中白桫椤表皮毛最丰富。黑桫椤副卫细胞有泡状突起,白桫椤副卫细胞有皱褶,其余4种副卫细胞表面均光滑无纹饰。笔筒树气孔器周围有绒毛层覆盖。黑桫椤、笔筒树气孔器表面有晶体。本研究结果表明2属6种叶表皮微形态特征多样性较为丰富,这些特征可作为种间鉴别的参考依据。

Scann ing electron microscope（ SEM） was used to observe the leaf surface ornamentation of China Cyatheaceae, including leaf trichomes, stomatal type, stomatal size, stomatal ornamentation. On the basis of observation of leaf epidermal micro-morphology and comparasion of thieir taxonomic significance, we conducted a retrieval table. Results showed that the leaf surface ornamentation of 6 species in 2 genera in China Cyatheaceae was ridged, the stomata size had no significant differences, and the stomata type belonged to paracytic. Trichomes had four kinds（including cystic hair, flaky hair, whisker hairs, peltate scales）, each species had large differences in trichomes, and Sphaeropteris brunoniana was the most abundant. Subsidiary cells of Alsophila podophylla had bubble-like protrusions, and subsidiary cells of S. brunoniana were wrinkled shape. The surface of subsidiary cells in other four species were smooth and without ornamentation. The stomata of S. lepifera was surrounded by fluff layer. The stomatal surface of A. podophylla and S. had crystals. The observations showed that the diversity of leaf epidermal morphology in the six species is rich, and the features are useful in taxonomic analysis of these species.