Abstract/Summary

The work presented in this thesis evaluates the status of Peninsular Malaysian Cyatheaceae and used molecular and morphological identification tools for the local species. 419 Cyatheaceae frond sample were collected from the widest possible range of Peninsular Malaysia to obtain material for morphology and molecular study. 15 Cyathea species were identified and the species information for Peninsular Malaysia was updated. The species was incorporated into the existing Cyatheaceae phylogeny by using four plastid regions: matK, rbcL, trnG-trnR and trnL-trnF. Bayesian MCMC analysis of the concatenated sequence data resulted in a 50% majority rule consensus tree confirm the placement of the four groups: Cyathea, Alsophila, Gymnosphaera and Sphaeropteris in the family. However, the resulting tree representing nested monophyletic groups, proposing Cyatheaceae to be monogeneric, i.e., Cyathea with two large groups: Cyathea and Sphaeropteris. The same plastid regions were then evaluated to develop DNA barcodes. trnL-trnF was proposed as a barcode for this family as it almost satisfied the three most important criteria: primer universality, sequence quality and species discrimination. This research also developed a multiaccess key for Cyatheaceae field identification based on fifteen taxa identified, by extensive field sampling of the currently recognised species. All of the Cyatheaceae species recognises in this study had also been assessed for the conservation status based on the IUCN Red List criteria. Nine species fall under Least Concern (LC), four species are Near Threatened (NT) and two species are Vulnerable (VU). The thorough knowledge regarding Cyatheaceae in Peninsular Malaysia gained through the work done in this research will benefit in making appropriate conservation strategies for the survival of this family. Overall, the most important outcome of this research was the combination of morphology and molecular data for the purpose of updating taxonomy, identification and conservation of the Cyatheaceae family in Peninsular Malaysia.