剑叶凤尾蕨配子体发育的研究

The Gametophyte Development in Pteris ensiformis

剑叶凤尾蕨(Pterisensiformis)是凤尾蕨科(Pteridaceae)凤尾蕨属(Pteris)多年生常绿草本植物,具有较高的观赏和药用价值。但是,目前对其繁殖过程还缺乏了解,限制了剑叶凤尾蕨资源的开发利用。本文报道了成功地采用混合土培养剑叶凤尾蕨的孢子,并系统地观察记录其孢子萌发及配子体发育过程。剑叶凤尾蕨的孢子呈褐色,赤道面观豆形,极面观三角形,单裂缝。播种1周左右孢子萌发,萌发类型为书带蕨型,配子体发育为水蕨型。播种3周左右发育为片状体。幼原叶体不对称,成熟原叶体裸露,无毛状体,呈心脏形。播种5周左右开始有性器官出现,精子器由3细胞组成,成熟颈卵器颈部由4列细胞组成,4层细胞高。原叶体受精后1个月内即可观察到从原叶体上生成的幼胚。该研究为园艺学研究提供了用孢子人工繁殖剑叶凤尾蕨的方法,也为分子生物学、遗传学和蕨类植物系统学研究提供了基础。

Pteris ensiformis is a perennial evergreen herbage with high ornamental and medicinal value. However, its resources have not been explored and utilized because of lack of understanding of its propagation. We successfully cultivated the spores of P. ensiformis in mixed soil and observed spore germination and gametophytic development by microscopy. The spores are brown, monolete, and bean-shaped in the equatorial view and triangular in the polar view. They germinate about 1 week after sowing. The germination is of the Vittaria type and the gametophyte development of the Ceratopteris type. The prothallial plate is formed about 3 weeks after sowing. The young prothalli are asymmetric and the mature are cordate and naked. The sex organs appear about 5 weeks after sowing. The antheridia consist of 3 cells. The archegonial neck usually consists of 4 rows and 4 columns of cells at maturity. Young embryos can be observed from the prothalli 1 month after sowing. This study reveals not only the technique of propagation of P.ensiformis with spores for horticulture but also the proper conditions for molecular biology, genetics and systematics study.