【摘要】 地理环境的不同造就了植物不同的适生机制。本研究对岩溶区和非岩溶区的扇叶铁线蕨(Adiantumflabellulatum)的叶片进行了比较,结果表明,二者在显微结构和亚显微结构方面都存在明显区别。在显微结构方面:岩溶区生长的扇叶铁线蕨的叶片具有旱生植物叶片特点,即叶片为等面叶,叶肉细胞排列较为紧密以及叶片维管组织发达等;而非岩溶区生长的扇叶铁线蕨的叶片为异面叶,特点为叶肉细胞排列相对疏松,维管组织不发达。扫描电镜分析显示:非岩溶区扇叶铁线蕨叶片表面具有很多明显的凹槽状结构,而岩溶区扇叶铁线蕨的叶片与之有明显不同,其叶片表面特别是叶脉位置具有明显的刺状结构,超薄切片发现这些刺状膨大部分细胞内存在液泡结构,并且这些刺状结构在叶片抽真空的过程中变瘪,说明这些刺状结构可能具有储存水分的功能。岩溶区扇叶铁线蕨特有的显微和亚显微结构保证了该种植物在岩溶干旱环境中可以正常生长。更多还原

【Abstract】 Different geographical environments lead to different mechanisms of plant ecological adaptation. This comparative study showed that the leaf microstructure and submicroscopic structure of Adiantum flabellulatum, growing in Karst and non-Karst areas, varied widely. The leaf in the Karst area was isolateral and had closely arranged mesophyllous cells. The more developed vascular system can favor water absorption in a dry environment. On the contrary, the leaf grown in the non-Karst area was bifacial, with loosely arranged mesophyllous cells and an undeveloped vascular system. Scanning electron microscope revealed that the leaf epiderm in Karst areas has many culticular spines, and the basal part of the culticular spines was extremely expanded. Further research revealed that the basal part of the culticular spines was shrunken when the leaf was devoid of water in a vacuous environment, which indicated that the culticular spine has the function of supply- ing water in a drought environment.更多还原