白茅解剖结构和屏障结构特征研究

摘要

利用光学显微镜和荧光显微镜对白茅进行了解剖学和组织化学研究，结果表明：1）白茅不定根解剖结构为表皮、外皮层、厚壁机械组织层、皮层、内皮层和中柱；根茎结构为角质层、表皮、周缘厚壁机械组织层、皮层、厚壁机械组织层和髓。2）不定根具内侧内皮层及其邻近皮层细胞、外侧表皮和皮下层组成的屏障结构；根茎具内侧厚壁机械组织层、外侧角质层和周缘厚壁机械组织层组成的屏障结构，屏障结构胞壁具凯氏带、木栓质和木质素沉积的组织化学特点。3）白茅通气组织包括根中通气组织，茎皮层通气组织和维管束中的气腔。4）白茅的屏障结构和解剖结构是其适应湿地环境的重要特征，但是根茎周缘厚壁机械组织层没有栓质化，髓部没有髓腔，推测其在湿地环境中分布有一定的局限性。%The anatomical structure and apoplastic barriers of congo grass (Umperata cylindrica )were studied using an epifluorescence microscope.The results showed that the anatomical structure of adventitious roots consisted of epidermis,exodermis,sclerenchyma ring,cortex,endodermis and stele.The anatomical structure of the rhizome consisted of cuticle,epidermis,peripheral mechanical ring,cortex,sclerenchyma ring and pith. The apoplastic barriers in the adventitious roots of congo grass have inner layers consisting of endodermis and neighbor cortex and outer layers consisting of epidermis and hypodermis.Apoplastic barriers in the rhizome have inner layers consisting of sclerenchyma ring and outer layers consisting of cuticle and peripheral mechani-cal ring.The cell walls of apoplastic barriers deposited as Casparian bands with suberin and lignin.The aeren-chyma of congo grass consisted of aerenchyma in adventitious roots,and cortex aerenchyma and air chambers in vascular bundles in the rhizome.The apoplastic barriers and anatomical structures of congo grass are important characteristics for adapting to wetlands.However,the characteristics of a peripheral mechanical ring without suberin and pith without cavities may limit congo grass growth in wetlands.