Studies on the gametophyte development of Phanerophlebiopsis blinii (Lévl.) Ching (Dryopteridaceae).

The spores of Phanerophlebiopsis blinii(Levl.)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.