REPRODUCTIVE BIOLOGY OF CALYMPERES IN SINGAPORE

Abstract

The main objectives of this thesis are to test out the hypothesis- whether there is a direct negative correlation between asexual and sexual reproduction and to find out on the frequency of sexual reproduction in Calymperes. Results have proven that asexual and sexual reproduction occurs concomitantly in Calymperes and sexual reproduction is rare in the dioecious moss. Field trips are also made to check out the distribution of Calymperes species in Singapore and specimens are brought back to laboratory for identification and reproductive studies. For some species ofbryophytes, the spore size and average number of spores produced per capsule are investigated, but not in Calymperes. Thus an estimation of spore number per capsule and the gemma capacity per plant are given. The spore size and average number of spores produced per capsule in Calymperes are computed in comparison with other species of bryophytes. A loose inversion correlation between spore diameter and spore output per capsule can be seen (Longton and Schuster, 1983). The pattern of position of perichaetial and perigonal are rather intriguing and diagrams are made on them since no works have been done on Calymperes in Singapore before. There could possibly lies evolutionary significance in these branching patterns. Also, the positions of antherdia, archegonia and sporophyte plants of 1 cm 2 are mapped out to show their distribution in a population. Results have shown that the more interspersed the distribution of male and female plants, the more sporophytes are produced in a population. A good example would be C. boulayi which has a mosaic distribution of male and female plants. During the study of the sexual and asexual structures, the morphology of gemmae and the varying length of the archegonium in Calymperes species show good characters on which taxonomic differentiation can be made. Hence, a key is made to identify the species.