粗齿黔蕨配子体发育的研究

用原生境腐殖土对粗齿黔蕨(Phanerophlebiopsis blinii(Lévl.)Ching)的孢子进行培养,显微镜下观察孢子萌发和配子体发育过程.结果表明:粗齿黔蕨的孢子深棕色,单裂缝,极面观椭圆形,赤道面观为半圆形.播种1周后孢子萌发,萌发类型为书带蕨型(Vittaria-type),配子体发育为叉蕨型(Aspidium-type).丝状体由4～12个细胞组成,片状体宽达9个细胞,斜向一侧生长,边缘具毛状体.播种约2个月后形成原叶体,成熟原叶体成对称心形.在粗齿黔蕨的配子体发育过程中,成熟原叶体的背腹面和边缘均被毛状体,假根有分叉且尖部常膨大,并含有较大的颗粒状贮藏物,精子器有3个壁细胞等特征较为进化,而颈卵器粗短且直立的特征较为原始.粗齿黔蕨的精子器和颈卵器发育不同步,精子器的出现和成熟均早于颈卵器的发育.从配子体发育的角度,初步探讨了粗齿黔蕨野外种群数量较少的成因.

Studies on the Gametophyte Development of Phanerophlebiopsis blinii (Lévl.) Ching (Dryopteridaceae)

The spores of Phanerophlebiopsis blinii (Lévl.) Ching were cultured in humus soil of pro-habitat. The spore germination and the gametophyte development were observed under microscope. The spores are dark-brown, monolete, elliptical in polar view and hemicyclic in equatorial view. The spores germinate about one week after sowing. The type of germination is Vittaria-type, and that of gametophyte development is Aspidium-type. Germ filament is consisted of 4 to 12 cells. Prothallial plate is usually lopsided with 9-cell width. Mature prothallus are cordate-thalloid with unicellular papillate hairs on the margin as well as the dorsal and ventral parts. More advanced characteristics, such as rhizoids usually are bifurcated and enlarged on the apex with granular stored substances, and antheridium is consisted of three wall cells. However, short and vertical neck of archegonia is a rather primitive character. The gametophyte development of Phanerophlebiopsis blinii is asynchronous, the development and maturation of antheridia is earlier than that of archegonia. From the view of characteristics of gametophyte development, the possible reasons of restricted distribution of P. blinii in the field environment were discussed.