The phylogeny, biogeography and morphological evolution of Gaultheria (Ericaceae) from Australia and New Zealand

摘要

Phylogenetic relationships within Gaultheria L. from Australia and New Zealand were examined by using DNA sequence data from matK, ndhF, nrITS, waxy and lfy. In the combined parsimony and maximum likelihood analyses, all Australia/New Zealand species form a clade that is sister to a clade of temperate South American species. Optimisation of morphological characters that have been emphasised in classifications of Gaultheria onto the molecular phylogeny revealed that, within the Australia/New Zealand clade, non-fleshy fruiting calyces, berries and solitary-flowered inflorescences each evolved twice, from fleshy fruiting calyces, capsules and multiple-flowered inflorescences, respectively. A historical biogeographical analysis that included the temperate southern hemisphere element in Gaultheria supports a South American origin of the Australia/New Zealand clade, followed by three dispersal events from New Zealand to Australia. Whether the origin is from temperate or tropical South America is ambiguous in our analysis.