银粉背蕨配子体及幼孢子体发育的研究

银粉背蕨是一种小型观赏蕨类植物，但目前我国对该蕨的研究还不够成熟。本文利用改良Knop's培养基和腐殖土培养银粉背蕨的孢子，观察其配子体及幼孢子体形态发育特征，并研究了其配子体发育的最适培养基pH值。研究结果显示：（1）银粉背蕨孢子黄褐色，具三裂缝，极面观三角圆形，赤道面观为近半圆形，孢子具网状纹饰；孢子萌发为书带蕨型；原叶体发育为水蕨型；颈卵器和精子器为薄囊蕨型；成熟原叶体为对称的心脏形，不具毛状体；上述特征为银粉背蕨孢子和配子体发育的稳定特征。（2）培养基pH值在7.0~9.0时随着碱性的增强，银粉背蕨孢子萌发和配子体生长发育速度逐渐增加。（3）利用腐殖土培养银粉背蕨孢子，7~8周可发育成幼叶，成苗率达90%，成苗健壮，根系发达，是扩繁银粉背蕨的适宜方式。本文为资源植物银粉背蕨人工繁殖和演化研究提供科学依据。

Development of Gametophyte and Young Sporophyte of the Fern Aleuritopteris argentea

Aleuritopteris argentea is a small ornamental ferns. We observed the developmental features of gametophyte and sporophyte of A.argentea cultured in Knop's medium and humus medium using microscopical techniques, and studied the optimum pH value for the gametophyte development. The results show that:(1)the spores are yellow-brown, tetrahedral, and trilete with reticulate ornamentations. Polar view is triangle circle and the equatorial view is nearly semicircular. The germination is Vittaria-type and the gametophyte development is Ceratopteris-type. The mature gametophytes are cordate. The archegonia and antheridia are leptosporangiate-type. No hairs are formed during gametophyte development. The above features of the gametophytes in the fern A.argentea are stable. (2)the enhancement the pH value in 7.0-9.0 is beneficial for spore germination and gametophyte development. (3)the spore and gametophytes develop on humus medium produced seedlings after 7-8 weeks. The viability of sporophytes obtain in this medium are strong with developed roots and easy to transplant. Percentage of seedling emergency reaches to 90%. Our investigation is benefit for the artificial propagation and evolution of the resource plant A.argentea.