Observation on the Gametophyte Development of Dryopteris subtriangularis

The spores of the Dryopteris subtriangularis were cultured in the mixed soil. The spore germination and the gametophytic development were observed by microscope. The result exhibits that the spores are dark-brown, monolete, and bean-shaped in equatorial view and elliptical in polar view. The spores germinate about one week after sowed, the germination is of the Vittaria-type while the gametophyte development is the Aspidium-type. The prothallial plates form about two weeks after sowed. The young prothalli develop in four weeks after sowed and the mature prothalli are cordate. Profuse unicellular hairs occur in the undersurface and on the margin of the prothalli. The sex organs form in six weeks after sowed. The antheridia are like pellets and formed by three cells. The archegonial neck is usually formed by four rows of cells and three to five cells high at maturity. Young embryos can be observed growing from the prothalli in one month after sowed.