臺灣山蘇花孢子發芽與配子體發育之研究

Studies on Spore Germination and Gametophyte Development of Asplenium nidus L.

臺灣山蘇花孢子發芽與配子體發育之形態於光學顯微鏡下觀察。孢子具雕刻狀花紋外膜，假根為單細胞，細胞質集中於前端。原絲體具葉綠體有自營能力；藏精器位於原葉體下側呈褐色塊狀；藏卵器散布於原葉體腹面上部，為暗綠色。無菌播種後10天孢子發芽，30天發育為二次元原葉體，45天發育為心臟形配子體；各約經85、110天分化藏精器、藏卵器，150天後由配子體腹面長出第一片孢子體葉片。無菌播種培養基成分以1/2MS基本鹽類較佳，添加1～2%蔗糖能促進配子體發育，外加GA3誘引藏精器之分化，孢子於剛成熟之夏季播種發芽率最高。

Morphometry of spores germination and development of gametophytes Asplenium nidus were investigated under steromicroscope. Spores had exine coated. Rhizoid was single-celled and cytoplasm accumlated in the antherior region. Protonema cells riched in chloroplasts. Brown, thimble-shaped antheridia were produced on the lower underside of the prothallium. Archegonia were clustered over the upper ventral of the same gametophyte. Spore germination to form rhizoid and protonema cells occurred 10 days after sowing on agar cultural medium. At 30 days after sowing, filamentous protonema transmitted to form two-dimensional prothallus. About 45 days later, heart-shaped gametophyte formed apical meristem. Antheridia and archegonia were produced at about 85 and 110 days after sowing, respectively. The first sporophytic frond was visible at about 150 days after sowing. For spore germination and gametophyte development, half-strength of MS medium was better than other media such as Knudson C, 1/4 MS and MS. The optimum sucrose concentration was 10~20 g/l. Plant hormone GAs promoted sexual differentiation of gametophytes. Spores matured in summer and sown immediately under sterile conditions exhibited higher germination and faster gametophyte development than the spores harvested late season in December or Febrary.