Development and Apogamy of the Gametophyte of the Fern Pteris fauriei

The gametophytic development of the fern Pteris fauriei Hieron.was observed by microscope and stereomicroscope.The result exhibits that the spores are dark brown,tetrahedral,and trilete,blunt triangular in polar view and super-semispherical shape in equatorial view.The spores germinate about 3-7 days after sowed.The germination is of the Vittaria type.The gametophyte develops into 6-10 cell-long filament about 18 days after sowed.The prothallial plates form about 25 days after sowed by division of the apical cell or intercalary cells of the filament.The gametophyte forms the meristematic tissue in the lateral of the plate,away from the apical region,and grows into prothallus in about 40-50 days after sowed.The pattern of the prothallial development belongs to the Ceratopteris type.The male prothalli are usually small and irregular in shape.The antheridia are produced in the margin or in the ventral side of the male prothalli.The large prothalli are usually regular in shape and cordate in the apical.An asexual bud is formed in the lower surface of the gametophyte just behind the growing apex in about 2-3 months after sowed.After the asexual bud is formed,a vessel is formed between the bud and the growing apex.So the reproduction of the species P.fauriei is apogamous.The repeat cultures show that no archegonia were occurred in the adult prothalli.This species belongs to obligate apogamy.