卷柏属(Selaginella)管状分子的研究

Study on Tracheary Elements of Selaginella

[目的]研究卷柏管状分子的类型和特点。[方法]用扫描电子显微镜对经离析法处理的4种卷柏属植物的茎进行观察。[结果]中华卷柏和蔓出卷柏中具有管胞,其中蔓出卷柏中还可见梯状穿孔的管状分子,推测可能为导管;圆枝卷柏、垫状卷柏仅观察到导管,有梯状穿孔以及网状-梯状混合型穿孔2种类型。这4种卷柏中,圆枝卷柏和垫状卷柏的管状分子最为进化,蔓出卷柏次之,中华卷柏最原始。垫状卷柏、蔓出卷柏和中华卷柏的管状分子类型为首次报道。卷柏管状分子类型的不同可能与其生境有关。[结论]该研究为验证同形叶和异形叶类型卷柏管状分子的差别以及探讨卷柏管状分子的演化问题奠定了基础。

[ Objective] The aim was to study the type trod characteristic of traeheaiy elements of Selaginella. [Method] The stem of four species of Selaginella plants treated by the segregation method was obser,＇ed by scarnaing electron microscopy （SEM）. [Result] Selaginella sinensis and Selaginella davidii had tracheids and the traeheary elements with scalariform perforation plates were observed in the latter, which were conferred as vessel. Only vessels were observed in Selaginella sanguinolenta and Selaginella pulvinata, including two types of＂ sealariform perforation plates and reticulate-scalariform perforation plates. The tracheary elements of S. sanguinolenta and S. pulvinata were the most evolutio,ary, followed by S. davidii anti that of S. sinensis was the most primitive in the four species of Selaginella. The types of trachealy elements of S. pulvinata, S. davidii and S. sinensis were first reported. The different types of tracheary elements had some correlation to their habitats. [Conclusion]The research laid the fntmdation for validating the difference of tracheary elements in isomorph leaf type of Selaginella and heteromorphic leaf type of Selaginella, and diseussing the evolution problem of the tracheary elements of Selaginella.