title: Phylogeny of Acronychia (Rutaceae) and First Insights into Its Historical Biogeography and the Evolution of Fruit Characters.
abstract: BACKGROUND
  The genus Acronychia (Citrus family, Rutaceae) contains 49 species of trees and shrubs that are found mainly in rain forest. The genus has a large distributional range from mainland southern Asia to Australia and New Caledonia, but most species are endemic to either New Guinea or Australia. This study aimed to provide the first detailed molecular phylogeny of Acronychia and use it to test the taxonomic value of fruit morphological characters, and infer the historical biogeography of the genus.
  
  
  METHODS
  Phylogenetic analyses (Bayesian Inference, Maximum Likelihood) were undertaken on nucleotide sequence data from two plastid (psbA-trnH, trnL-trnF) and three nuclear markers (ETS, ITS, NIAi3) from 29 Acronychia species (59% of the genus) and representatives of related genera.
  
  
  CONCLUSIONS
  The results indicate that the South-East Asian genus Maclurodendron is nested phylogenetically within Acronychia and must be synonymized to render Acronychia monophyletic. Fruit morphological characters have been used previously to infer relationships within Acronychia and our analyses show that these characters are informative for some subclades but are homoplasious for the group as a whole. Apocarpous fruits are the ancestral state in Acronychia and subapocarpous and fully syncarpous fruits are derived. The unisexual flowers of Maclurodendron are derived from bisexual flowers, which are found in all species of Acronychia as well as its relatives. Acronychia probably first evolved on Australia with range expansion to New Guinea via stepping-stone dispersal or direct land connections within the Sahul Shelf, followed by two independent dispersals to areas west of New Guinea. Most species of Acronychia occur in either Australia or New Guinea, but no species occurs in both regions. This is surprising given the close proximity of the landmasses, but might be explained by ecological factors.
authors: Department of Systematics, Biodiversity and Evolution of Plants, University of Göttingen, Untere Karspüle 2, Göttingen, Germany.
authors: Laura
authors: L
authors: Holzmeyer
authors: National Herbarium of New South Wales, Royal Botanic Gardens & Domain Trust, Sydney, Australia.
authors: Marco
authors: M
authors: Duretto
authors: Australian Tropical Herbarium, James Cook University, Cairns, Australia.
authors: Darren
authors: D
authors: Crayn
authors: Department of Systematics, Biodiversity and Evolution of Plants, University of Göttingen, Untere Karspüle 2, Göttingen, Germany.
authors: Elvira
authors: E
authors: Hörandl
authors: National Herbarium of New South Wales, Royal Botanic Gardens & Domain Trust, Sydney, Australia.
authors: Margaret
authors: M
authors: Heslewood
authors: Australian Tropical Herbarium, James Cook University, Cairns, Australia.
authors: Janani
authors: J
authors: Jayanthan
authors: Department of Systematics, Biodiversity and Evolution of Plants, University of Göttingen, Untere Karspüle 2, Göttingen, Germany; Department of Botany, Smithsonian Institution, Washington, DC, United States of America.
authors: Marc S
authors: MS
authors: Appelhans
mesh_terms: D001483:Base Sequence / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics; D019143:Evolution, Molecular; D005638:Fruit / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D058974:Phylogeography; D027821:Rutaceae / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D018742:DNA, Chloroplast