Gametophyte Development in Anemia mexicana Klotzsch

Abstract

Gametophyte development was investigated for two southwest Texas populations of Anemia mexicana Klotzsch. Spores in axenic multispore cultures germinated 3 days after sowing. Early developmental characteristics included formation of two-dimensional prothalli at 5 days, three-dimensional prothalli at 9 days, and initiation of lateral meristems at 9 days. Terminal meristems resulted from uneven growth of the wings. Unicellular marginal trichomes were formed 4 days after meristem organization. Antheridia were observed at 19 days and were present on gametophytes with and without organized meristems. Gametophytes with organized meristems that lacked antheridia formed archegonia at 27 days. Both antheridia and archegonia were morphologically similar to those of other Anemia species. Most gametophytes were unisexual; some bisexual gametophytes eventually were present. Bisexual gametophytes had terminated antheridia formation and begun to form archegonia. After 60 days, six variations in gametophyte morphology were observed. Intraspecific variations were seen in gametophyte morphology, time of initiation of different developmental characteristics, and percentage of each variation at 60 days. Sporophytes were observed at 4 mo.