苏铁类植物4个属的导管与被子植物导管结构特征的比较研究

 对苏铁属的台湾苏铁(Cycas taiwaniana)、波温铁属的细齿波温铁（Bowenia serrulata）、双子铁属的双子铁(Dioon edule)叶的羽片，大泽米铁属长刺大泽米铁（Macrozamia longispina）的根，以及被子植物的白兰（Michelia alba）和桃（Amygdalus persica）的叶组织进行了电子扫描显微镜的观察研究，结果表明，2个科4个属苏铁植物的导管类型是丰富的，导管的结构组成方式、发育过程与被子植物是一致的；例如导管端壁倾斜度等结构特征显示，一些被子植物导管的结构比苏铁类植物的要原始。在被子植物的导管中有许多为端部呈扁平的带状，而且还带有扭曲状，没有端壁，只有两面的侧壁及另两侧的很窄的边，在带状的侧壁上具有许多的穿孔。这在过去未见有报道。对苏铁类植物导管的认识，对于我们进一步了解现存最原始的种子植物对严酷环境的适应机制和进化状况，对于采取有效措施保护这些珍稀的植物类群，以及对于结构植物学、植物进化和生态学等研究方面均具有重要的意义。

Comparative Studies on Structural Feature of Vessels of Four Genera of Cycads with Angiosperm

The tissues of leaf of Cycas taiwaniana,Bowenia serrulata and Dioon edule and tissue of root of Macrozamia longispina of cycads, and leaves of Michelia alba and Amygdalus persica of angiosperm were observed by scanning electron microscope. The results showed that there are many types of vessels in four genera of two families of cycads,the manner and process of development and constitution in structural characteristics of vessel of cycads and angiosperm are identical,some characters of vessel such as inclined extent of perforation plate of end wall etc. showed that some angiosperm are more primitive then that of cycads. In vessels of species of angiosperm, many are band shape, and without end wall, only have two lateral walls and another two narrow margins, the top is acute or with an arc margin, many perforations located in lateral wall. Cognized to vessel of cycads, help us to understand the mechanism which these most primitive seed plants extant how to adapted to harsh environments and their evolutionary level, and has significance to use efficiency measure protect these rarity plants and has significance to plant anatomy, plant systematics and plant evolution.