Molecular and morphological agreement in Pittosporaceae: phylogenetic analysis with nuclear ITS and plastid trnL–trnF sequence data
Gregory T. Chandler A E , Gregory M. Plunkett B , Steven M. Pinney B , Lindy W. Cayzer C and Chrissen E. C. Gemmill DA Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403-5915, USA.
B Department of Biology, Virginia Commonwealth University, Richmond, VA 23284-2012, USA.
C Australian Government Department of Agriculture, Fisheries and Forestry, PO Box 858, Canberra, ACT 2601, Australia.
D Centre for Biodiversity and Ecology Research, Department of Biological Sciences, University of Waikato, Hamilton, New Zealand.
E Corresponding author. Email: chandlerg@uncw.edu
Australian Systematic Botany 20(5) 390-401 https://doi.org/10.1071/SB07004
Submitted: 3 February 2007 Accepted: 30 July 2007 Published: 8 November 2007
Abstract
Pittosporaceae are a small family of flowering plants largely restricted to Australia, and entirely limited to the paleotropics. Two independent molecular datasets have been constructed with a representative sample from all nine genera of Pittosporaceae to test phylogenetic relationships suggested by recent morphological studies and to examine current morphological delimitations of genera. DNA sequence data derived from the ITS region of nuclear rDNA and from the trnL–trnF region of the chloroplast genome agree in uniting all species sampled from Pittosporum within a single clade, together with all species sampled from the previously segregated genus Citriobatus. Molecular data also confirm that members of the recently established genus Auranticarpa must be excluded from Pittosporum, and that another segregate genus, Sollya, should be placed within Billardiera. Hymenosporum remains a distinct, single-taxon lineage and Rhytidosporum is also confirmed as distinct. In most respects, our results are in agreement with recent taxonomic revisions based on morphology, and support an Australian origin of Pittosporaceae. Multiple dispersal events of Pittosporum from Australia to the islands of the Pacific and Indian Oceans, including New Zealand, are suggested, as well as island hopping throughout the Pacific.
Acknowledgements
The authors thank The Australian National Botanic Gardens for fresh material of many members of Pittosporaceae used in the present study, and the Australian National Herbarium (CANB) for access to herbarium material. This work was supported by grants to GMP from the USA National Science Foundation (DEB 9981641), the National Geographic Society (5793–96) and the Thomas F. and Kate Miller Jeffress Memorial Trust (J-506). Finally, we thank the two anonymous reviewers for their valuable and constructive comments.
Angiosperm Phylogeny Group
(1998) An ordinal classification for the families of flowering plants. Annals of the Missouri Botanical Garden 85, 531–553.
| Crossref | GoogleScholarGoogle Scholar |
[verified 21 September 2007].
Webb LJ,
Tracey JG, Jessup LW
(1986) Recent evidence for autochthony of Australian tropical and subtropical rainforest floristic elements. Telopea 2, 575–589.
Wen J,
Plunkett GM,
Mitchell AD, Wagstaff SJ
(2001) The evolution of Araliaceae: a phylogenetic analysis based in ITS sequences of nuclear ribosomal DNA. Systematic Botany 26, 144–167.
Wilkinson HP
(1992) Leaf anatomy of the Pittosporaceae R.Br. Botanical Journal of the Linnean Society 110, 1–59.
