费菜和长药八宝叶形态结构及其与耐旱性关系的研究

利用光学显微镜观察比较了费菜（Sedum aizoon L.）和长药八宝（S. spectabilis Boreau）的叶表皮形态及解剖结构，并对其进行不同程度的水分胁迫，研究干旱逆境条件对其叶片显微结构的影响。结果表明：两种景天的叶形态、解剖结构与耐旱性之间存在较密切的相关性。两种植物成熟叶均具较薄的角质层和发达的储水组织，叶肉组织中没有栅栏组织和海绵组织的明显分化。二者的维管组织较发达，且具较发达的孔下室，维管束周边发现一些吸水能力较强的异细胞，这些特征是植物耐旱的关键。

Studies on Anatomical Structures of Leaves and Their Drought Tolerance Features of Sedum aizoon L. and Sedum spectabilis Boreau

Epidermal characters and anatomical structure of leaves of Sedum aizoon L. and S. spectabilis Boreau have been observed by the light microscope and the influence of the leaf anatomical structure of two species in different soil water stress were studied. The results showed that there was a strongly relationship between the morphological, anatomical structures with their drought adaptability. There have the thin cuticle and well-developed aquiferous tissues in the mature leaves of two species. And there was ambiguous differentiation between spongy and palisade tissue in mesophyll. The vascular bundle of S. spectabilis Boreau and S. aizoon L.were more developed and they have well-developed stomatic chamber which below the epidermic cell. We also discovered many idioblasts which can drank and reserved much water around the vascular bundle. These characters were the key factors for the drought tolerance of both two species.