Factors Initiating Antheridial Formation in Six Anthocerotales
1967; American Bryological and Lichenological Society; Volume: 70; Issue: 2 Linguagem: Inglês
10.1639/0007-2745(1967)70[203
ISSN1938-4378
Autores Tópico(s)Lichen and fungal ecology
ResumoIn species of Anthoceros, Phaeoceros, and Notothylas, photoperiod is the critical environmental factor in the initiation of antheridia while tempera- ture (10-250 C) has little effect. The purpose of this investigation was to study some environmental factors which effect the initiation of sexuality in several species of Anthocerotales as evidenced by the formation of antheridia. Although numerous studies of environmental stimuli which induce the reproductive phase in algae, fungi, and flowering plants have appeared, only recently have such studies of hepatics been reported. Photoperiod was implicated in gametophore pro- duction in Marchantia (Voth & Hamner, 1940; Anthony, 1962) and in the initiation of sexuality in five species of Jungermanniales (Morries, 1961). Recently, extensive investigations of conditions which evoke initiation of sexuality in liverworts have been published by Benson-Evans (1965), who reported that four species of Marchantiales and six of Jungermanniales are long-day plants (16-18 hours of light diurnally), while Riccia glauca and Anthoceros laevis are short-day plants (6-8 hours of light diurnally). She also cited some evidence that the photoperiodic effect is operative in many liver- worts only within certain temperature limits. In Preissia quadrata, Pellia epiphylla, and Anthoceros laevis, however, the photoperiodic induction of sexuality is operative over a wide temperature range, she found. In Cryptothallus mirabilis (Benson-Evans, 1961), temperature alone, particularly during the dark period, appears to be most influential. Monroe (1965) also found that temperature was the limiting factor in inducing sexuality in the moss Funaria hygrometrica.
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