中国十字花科独行菜属植物的叶表皮特征研究

目的:对中国十字花科独行菜属植物进行分类鉴别研究。方法:利用光学显微镜和扫描电镜观察了中国十字花科独行菜属10种植物的叶表皮形态。结果:独行菜属植物气孔器在叶上、下表皮均有分布,气孔类型主要为不等细胞型,其次为无规则型,在少数植物种类中偶见平列型;叶表皮细胞形状为多边形或不规则形,垂周壁一般为平直或弓形、浅波、波状;独行菜属植物在叶表皮特征上具有较强的一致性,同一种植物叶上、下表皮同形或近同形,叶表面仅被单毛或无毛;扫描电镜下叶片角质层通常具有条状波纹,气孔外拱盖内缘通常为浅波状或近平滑。叶表皮细胞形态、垂周壁式样、气孔类型、气孔指数与气孔器大小以及叶片角质层特征等对该属种的区分具有重要的参考价值。结论:叶表皮特征研究可用于中国独行菜属种间分类鉴别研究,为该属药用植物资源的合理应用和开发提供了新的依据。

Studies on the Leaf Epidermal Features of Lepidium(Brassicaceae) from China

Objective: Classification and diagnostic study on Lepidium(Brassicaceae) from China.Methods: Leaf epidermal micromophology of 10 species of Lepidium from China were observed by using LM(light microscope) and SEM(scaning electron microscope).Results: The stomatal apparatuses present both on the adaxial epidermis and the abaxial epidermis.The type of stomatal apparatuses is mainly anisocytic,rarely anomocytic and only occasionally paracytic.The leaf epidermal cells of Lepidium are usually irregular or polygonal in shape.The patterns of anticlinal walls are straight,arched,sinuolate or sinuous.The leaf features of Lepidium have better consistency.The morphology of the upper epidermis and the lower epidermis is similar,and with simple trichomes or glabrous on the leaf surface.Under SEM observation,the inner margin of the outer stomatal rim is nearly smooth or sinuolate,and the cuticular membrane of the leaf epidermis is striate.The shapes of leaf epidermal cells,the patterns of anticlinal walls,the types of stomatal apparatuses,the stomatal index,the stomatal size and the characters of the cuticular membrane of the leaf epidermis have important reference for differentiating species of Lepidium.Conclusion: The leaf epidermal features can serve as a criterion of distinguishing species in the genus Lepidium(Brassicaceae) from China,and also provide new evidence for rational use and exploitation of medical resources in Lepidium.