Systematics and biogeography of Myricaceae

Myricaceae--Classification;Biogeography

Herbert, Jane ; Abbott, Richard J. ; Abbott, Richard J.

University:University of St Andrews

Department:Biology (School of)

关键词: Myricaceae--Classification;    Biogeography;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/2687/JaneHerbertPhDThesis.pdf?sequence=3&isAllowed=y

来源: DR-NTU

【 摘 要 】

Two molecular phylogenetic studies were undertaken to examine relationships withinMyricaceae. Analyses of DNA sequences of the plastid rbcL gene, trnL-Fregion andnuclear ITS region showed the family to be monophyletic. In all analysesCanacomyrica, a monotypic genus endemic to New Caledonian that bears severaldistinctive features such as staminodes in the female flowers, fell into a well-supported clade sister to the rest of Myricaceae. Phylogenetic analyses of ITS andtrnL-F sequence data, representing all genera and subgeneric groups, were undertakenusing maximum parsimony and Bayesian methods. The following relationships werestrongly supported: (Canacomyrica (Comptonia (Myrica, Morella))). The cladecontaining all species formerly considered to comprise Myrica s.l. was split into twostrongly supported clades corresponding to Myrica s.s. and Morella; this findingstrengthens the argument for recognition of these as separate genera. Within Morella,two clades corresponded to previously recognized subgenera. Molecular datinganalyses were performed using Penalized Likelihood. Close correlations betweenlineage-specific diversification and major orogenic or climatic events were inferred.This study suggests that much of the diversity in Morella arose during the Neogeneand seed-dispersal by birds has been a significant factor in determining the modemdistribution. A study of the conservation status of Canacomyrica was conducted usingfield observations and data from herbarium specimens. This species was found tooccur in just eleven fragmented localities: six outside protected areas and threethreatened by mining or bush fires. IUCN Red List status of Endangered wasrecommended. The morphology and ecology of Canacomyrica was studied toenhance knowledge of this poorly known species and provide comparative data foruse in a study of the morphology of the entire family. A new classification schemewith keys was presented including, for the first time, Canacomyrica. Newcombinations in Morella were recommended.