title: Phylogeny of the plant genus Pachypodium (Apocynaceae).
abstract: Background. The genus Pachypodium contains 21 species of succulent, generally spinescent shrubs and trees found in southern Africa and Madagascar. Pachypodium has diversified mostly into arid and semi-arid habitats of Madagascar, and has been cited as an example of a plant group that links the highly diverse arid-adapted floras of Africa and Madagascar. However, a lack of knowledge about phylogenetic relationships within the genus has prevented testing of this and other hypotheses about the group. Methodology/Principal Findings. We use DNA sequence data from the nuclear ribosomal ITS and chloroplast trnL-F region for all 21 Pachypodium species to reconstruct evolutionary relationships within the genus. We compare phylogenetic results to previous taxonomic classifications and geography. Results support three infrageneric taxa from the most recent classification of Pachypodium, and suggest that a group of African species (P. namaquanum, P. succulentum and P. bispinosum) may deserve taxonomic recognition as an infrageneric taxon. However, our results do not resolve relationships among major African and Malagasy lineages of the genus. Conclusions/Significance. We present the first molecular phylogenetic analysis of Pachypodium. Our work has revealed five distinct lineages, most of which correspond to groups recognized in past taxonomic classifications. Our work also suggests that there is a complex biogeographic relationship between Pachypodium of Africa and Madagascar.
authors: Department of Botany, University of British Columbia , Vancouver, British Columbia , Canada.
authors: Dylan O
authors: DO
authors: Burge
authors: Kaila
authors: K
authors: Mugford
authors: Amy P
authors: AP
authors: Hastings
authors: Anurag A
authors: AA
authors: Agrawal
keywords: Africa; Apocynaceae; Biogeography; Flower color; ITS; Madagascar; Pachypodium; Phylogeny; Taxonomy; trnL-F
references: Mol Biol Evol. 1988 Sep;5(5):568-83
references: 3193878
references: Mol Phylogenet Evol. 1997 Oct;8(2):150-66
references: 9299221
references: Evolution. 1983 Mar;37(2):221-244
references: 28568373
references: Syst Biol. 2003 Oct;52(5):696-704
references: 14530136
references: Bioinformatics. 1998;14(9):817-8
references: 9918953
references: Bioinformatics. 2003 Aug 12;19(12):1572-4
references: 12912839
references: Am J Bot. 1998 Aug;85(8):1143
references: 21684999
references: Evolution. 1985 Jul;39(4):783-791
references: 28561359
references: Syst Biol. 2006 Feb;55(1):21-30
references: 16507521
references: Nucleic Acids Res. 2004 Mar 19;32(5):1792-7
references: 15034147
references: Nat Methods. 2012 Jul 30;9(8):772
references: 22847109
references: Am J Bot. 2005 Jan;92(1):142-66
references: 21652394
references: Trends Ecol Evol. 1996 Apr;11(4):152-8
references: 21237790
references: Plant Mol Biol. 1991 Nov;17(5):1105-9
references: 1932684
references: Am J Bot. 2010 Aug;97(8):1296-303
references: 21616882
references: Nature. 2007 Feb 15;445(7129):757-60
references: 17301791