GAMETOPHYTE DEVELOPMENT AND ANTHERIDIOGEN ACTIVITY IN THELYPTERIS-OVATA VAR. LINDHEIMERI

Gametophyte development was studied in Thelypteris ovata var. lindheim eri from spore germination to 48 days. Spores were sown aseptically on to the surface of agar-solidifed mineral medium in multispore cultures . Germination began four days after spore sowing. Gametophytes were sp atulate in morphology at six days and terminal meristems were initiate d at ten days. Antheridia were observed at 19 days, archegonia at 21 d ays. At 28 days, gametophytes were antheridiate (smaller, 0.6-1.0 mm i n width), archegoniate (larger, 1.3-2.3 mm in width) or asexual (varia ble, 0.5-1.5 mm in width). Gametophytes remained unisexual at 48 days. The presence of an antheridiogen system was investigated using cultur e media extracts of T. ovato gametophytes. Young gametophytes of T. ov ata and Onoclea sensibilis L. form antheridia prematurely when exposed to partially purified culture media extracts. Two bands of biological activity were present after thin-layer chromatography, indicating the presence of at least two biologically active compounds.