蜈蚣草孢壁发育及其系统学意义

利用光镜、扫描电镜和透射电镜对凤尾蕨科(Pteridaceae)蜈蚣草(Pteris vittata L.)孢壁的形成和发育进行研究。结果表明:蜈蚣草孢子四面体型,极面观钝三角圆形,赤道面观半圆形或超半圆形,近极面具瘤状纹饰和近极脊,远极面具脊并连成网状,具赤道环;孢子具乌毛蕨型外壁,由外壁外层构成纹饰的轮廓;实心型周壁由2层构成,且内层薄、外层具小球体。结合孢子外壁和周壁的发育特征,认为凤尾蕨科与裸子蕨科和水蕨科的亲缘关系较近,支持将裸子蕨科和水蕨科置于凤尾蕨科。

Development of Sporoderm and Their Taxonomic Significance in the Fern Pteris vittata L.(Pteridaceae)

The formation and development of sporoderm of the fern Pteris vittata L.(Pteridaceae) should be studied using light microscope (LM),scanning electron microscope (SEM) and transmission electron microscope (TEM).The results as follow:The spores are tetrahedral,round obtuse triangle in polar view,semi-circular or super semi-circular in equatorial view.The spores usually have tuberculate ornamentations and proximal ridge in the proximal surface,network ridges in the distal surface and the equatorial flange.The exospore,belonging to the Blechnum type,forms the outline of the spore ornamentations.The solid perispore is composed of two layers.The inner layer is thin and the outer layer is attached with small spherules.Based on the developmental features of the exospore and perispore,it is considered that Pteridaceae has close relationship with Hemionitidaceae and Ceratopteridaceae.The present results support the viewpoint that the Hemionitidaceae and Ceratopteridaceae are contained in the Pteridaceae.