水蕨孢子壁的形成和发育

利用光镜、扫描电镜和透射电镜对水蕨科(Parkeriaceae)水蕨(Ceratopteris thalictroides (L.) Brongn.)孢子壁的形成和发育进行了研究。结果表明, 水蕨孢子呈辐射对称, 三裂缝, 表面具肋条状纹饰。孢子壁由内壁、外壁和周壁三部分构成。在四分体阶段外壁已基本形成, 其外壁显著, 表面光滑, 质地均匀, 由孢粉素形成, 外壁厚约3-5 μm, 脊高约5-7 μm。周壁由绒毡层残余物在外壁表面沉积形成, 较薄, 厚度只有0.1 μm, 表面具有杆状突起。研究结果对揭示孢子纹饰和孢子壁各层的形成过程、来源和稳定性有一定的意义, 并为蕨类植物孢粉学和系统学研究提供基础资料。

Formation and Development of Sporoderm of Ceratopteris thalictroides (L.) Brongn. (Parkeriaceae)

The formation and development of sporoderm of the fern Ceratopteris thalic troides (L.) Brongn. (Parkeriac eae) were studied by means of light microscopy, scanning electron microscopy and transmission electron microscopy. The mature spores are radially symmetrical and trilete. The surface of spores is smooth and shows a rib-shaped (costate) ornamentation. The sporoderm consists of endospore, exospore and perispore. The exospore, which is formed by sporopollenint, is prominent; it is about 3-5 μm thick, and its rib-shaped ridges are about 5-7 μm high. The surface is smooth and the texture is uniform. The perispore is formed by the tapetal residues, which deposit on the outside of the exospore. The perispore is very thin, about 0.1 μm thick, with many small rod-like projections in the surface of perispore. The results will contribute to a better understanding of the origin, development and formation process of the sporoderm of ferns. They can also provide basic information about the palynology and phylogeny of ferns.