Sexual Life Cycle of Three Species of Funariaceae in Culture

Three species of the Funariaceae (Physcomitrella patens (Hedw.) B.S.G., Physcomitrium pyriforme (Hedw.) Hampe and Funaria hygrometrica Hedw.) have been cultured under sterile conditions on Knop's inorganic me- dium (liquid and agar) to determine the conditions and minimum time nec- essary for completion of the sexual life cycle (spore to spore). According to the data presented, the life cycle of F. hygrometrica may be completed in 4 months, P. pyriforme in 3 months and P. patens in 2 months. In all three species the critical factor for the induction and maturation of gametangia is cold temperature. Delineation of the life cycle makes these organisms suitable for genetic study. Studies concerning the reproductive phase in bryophytes in culture have been relatively few. Voth and Hammer (1940) implicated photoperiod as the stimulus nec- essary for gametophore production in Marchantia. Morris (1961) stated that in five species of leafy liverworts the onset of sexual reproduction is controlled primarily by photoperiod. Benson-Evans (1964) reported that four species of Marchantiales and six of Jungermanniales are long-day plants, while Riccia glauca and Anthoceros laevis are short-day plants. She also cited some evidence that the photoperiodic effect is operative in many liverworts only within certain temperature limits. Ridgway (1967) reported that in species of Anthoceros, Phaeoceros and Notothylas, photoperiod is critical in initiation of antheridia while temperature has little effect. Contrary to the cases reported for the liverworts and hornworts, temperature does seem to be the