中文摘要：

对通气组织的解剖观察有助于了解湿地植物的生长、分布及对不同生境的适应。采用石蜡切片技术,在光学显微镜下对洞庭湖湿地沿水位高程梯度分布的4种优势植物——荻Miscanthus sacchariflorus、水蓼Polygonum hydropiper、红穗苔草Carex argyi、虉草Phalaris arundinacea的茎和叶解剖结构进行了比较研究。结果表明：茎通气组织的形成部位主要在皮层、维管束和髓腔,其中髓腔所占比例最大（〉77%）。茎通气组织大小为：水蓼（57.8%）〉红穗苔草（45.5%）≥虉草（41.7%）≥荻（37.8%）。4种湿地植物的叶均在叶肉组织和（或）维管束内形成通气组织,如荻、虉草的形成部位是维管束,水蓼的是叶肉组织,而红穗苔草在叶肉组织和维管束内均可以形成,但以叶肉组织中为主,占99%。红穗苔草叶通气组织最发达,为33.8%,其它3种植物相对不发达,仅为0.13%～1.68%。除虉草外,其它3种植物通气组织大小与其分布位置具有很好的一致性。可见,湿地植物通气组织与其分布有较好的相关性。

英文摘要：

Anatomical observation of aerenchyma helps understand the growth,distribution,and adaptation of wetland plants to different habitats.Anatomical structures of the stem and leaf were carefully studied,using optical microscope and paraffin section technology,in four dominant wetland species（Miscanthus sacchariflorus,Phalaris arundinacea,Carex argyi and Polygonum hydropiper） distributed along a water-level gradient in Dongting Lake.Results showed that the stem aerenchyma was formed from three tissues,i.e.cortex,vascular bundles and the medullary cavity.Among them,the medullary cavity was the primary tissue for aerenchyma formation,accounting for more than 77%.The size of the stem aerenchyma from highest to lowest was：Polygonum hydropiper（57.8%）Carex argyi（45.5%）≥Phalaris arundinacea（41.7%）≥Miscanthus sacchariflorus（37.8%）.Leaf aerenchyma in Miscanthus sacchariflorus and Phalaris arundinacea was formed in the vascular bundles,Polygonum hydropiper in the mesophyll tissue,and Carex argyi in both mesophyll tissue（99%） and vascular bundles（1%）.Leaf aerenchyma of Carex argyi was highly developed,with a size of 33.8%.The other three species had relatively undeveloped leaf aerenchyma,with a size of only 0.13%-1.68%.Except for Phalaris arundinacea,the aerenchyma size was consistent with the sites of field distribution in Dongting Lake.These data indicate that the aerenchyma of wetland plants is closely related to its distribution.