盐肤木对岩溶干旱环境的适应性研究：叶片解剖结构的启示

Adaptation of Rhus chinensis to drought stress in karst area: Insights from anatomical structure of leaf

通过石蜡切片和扫描电镜观察,研究了岩溶环境下生长的盐肤木叶片结构特征。结果表明,在水分胁迫下,叶片表现了一系列的旱生特征。表皮由一层排列致密的不规则细胞组成。上表皮覆盖一层较厚的角质层,下表皮表面有表皮毛丛生。气孔着生在下表皮,陷入表皮以下。叶肉内栅栏组织发达,海绵组织松散。栅栏组织与海绵组织比约为4∶1。部分叶肉细胞中含有胶状结晶物质。叶脉中厚壁组织发达,木质部外纤维数量众多,在气腔周围有单宁结晶分布。这些特征表明,盐肤木采用以保护型为主的多种方式适应岩溶干旱环境。

Leaf structure of Rhus chinensis in karst area is studied by paraffin sectioning and electron microscope and some xerophilous structures are found in leaf under water stress. The epidermis is covered by a thick cuticle. Upper epidermis cell is composite by a dense cuticular layer. Lower epidermis is covered by epicuticle hairs and the sunken stoma existed in lower epidermis. The palisade tissue is rich and the spongy parenchyma is loose. The ratio of the palisade tissue to the spongy parenchyma is about 4：1. Some mesophyll cells contained colloidal crystal material. Sclerenchyma in leaf vein is quite developed. Out of the xylem, there is lot of fiber and the tannin crystal distributes around the air cavity. It is then concluded that Rhus chinensis adapts to the karst drought environment with protection type.