Reproductive Biology ofAglaomorpha cornucopia(Copel.) M.C. Roos, a Rare and Endemic Fern from the Philippines

Aglaomorpha cornucopia (Copel.) M.C. Roos is an endemic and rare epiphytic fern from the Philippines. Ex situ germplasm storage and growth are important complementary tools for conserving this rare fern. This study was conducted to document the reproductive biology of this species. Mature sporophylls of A. cornucopia were collected in May, 2012 from Mt. Apo, the Philippines. Each sporangium bore 64 yellow, monolete spores. The average spore size was 49.3±3.7 µm. Fresh spores germinated 100% within one week of sowing (mean germination time (MGT) <1 week). Air-dried mature spores remained completely viable even after one year of storage at 3°C, although mean germination time was somewhat delayed (MGT = 1.4 weeks). Spore germination was of the Vittaria-type, whereas gametophyte development was of the Drynaria-type. Adult gametophytes were cordiform-annual and gametangia were of the leptosporangiate type. Unicellular papillate hairs appeared on marginal, dorsal, and ventral surfaces of the gametophytes. Gametophytes first produced antheridia and archegonia after seven weeks of culture. Gametophytes began to sexually produce sporophytes after 13 weeks of culture. The rate of sporophyte production reached 64% after 26 weeks culture. Results of this study suggest that cold temperature spore storage and in vitro culture offer reliable techniques for conserving this rare fern.