Some Factors Evoking Formation of Sex Organs in Funaria

Abstract

In Funaria hygromrnetrica, low temperature (100 C) is the critical factor in the induction of sex organs while day length seems to have no effect as long as a certain minimum period of illumination is provided. The purpose of this study was to investigate some of the factors which effect the initiation of sexuality in Funaria hygrometrica Hedw. as evidenced by the formation and functioning of antherida and archegonia. Although the stimuli which trigger the onset of the reproductive phase have been investigated in algae, fungi, and flowering plants, the Bryophyta have been relatively neglected in this respect. Photoperiod has been implicated in gametangiophore production in the liverwort Marchantia (Voth & Hamner 1949) and has been shown to affect development, although not to cause initiation, of the sporophyte of Polytrichum aloides (Hughes 1962). Morris (1958) stated that in five species of leafy liverworts, the onset of sexual reproduction is primarily a photoperiodic response. Benson-Evans (1964) reported that sexuality in Sphagnum plumulosum is initiated by short days but that Polytrichum aloides appears to be day length neutral and, in fact, initiation of sexuality is temperature-dependent. Von Wettstein (1924) was able to bring about sexual reproduction in Funaria hygrometrica by 'culturing it in pots on the north side of his Moosgewichshaus where, he stated, the plants would remain especially cool in