Evolution and biogeography of Centaurea section Acrocentron inferred from nuclear and plastid DNA sequence analyses

• DOI: 10.1093/aob/mcp022
• Publication Date: 2009-02-20T01:15:17Z
• Authors: M. Font; N. Garcia-Jacas; R. Vilatersana; C. Roquet; A. Susanna
• Keywords: Vicariance; Centaurea; Peninsula; Molecular clock

Background and Aims Section Acrocentron of the genus Centaurea is one largest sections with approx.100 species.The geographic distribution, centred in Mediterranean, makes it an excellent example for studies biogeographic history this biodiversity-rich region.† Methods Plastid (trnH-psbA) nuclear (ITS ETS) DNA sequence analysis was used phylogenetic reconstruction.Ancestral patterns were inferred by dispersal-vicariance (DIVA). † Key ResultsThe resulting phylogeny has implications sectional classification confirms merging sect.Chamaecyanus into as a subsection.Previous suggestions eastern Mediterranean origin group are confirmed.The main centres diversification established previous now strongly supported.Expansion two different radiations that followed patently diverse paths inferred.† Conclusions Radiation waves, widely separated time scale.The oldest one, from Turkey to Greece northern Balkans then North Africa Iberia, should be dated at end Miocene Messinian period.It reached Iberian Peninsula south, following route landmarked several relictic taxa Sicily Africa.A later radiation during Holocene interglacial periods followed, involving species north Balkan Peninsula, along Eurasian pathway running Central Iberia steppes Kazakhstan.A generalized pattern reticulation also evident results, indicating past contacts between presently species.Molecular data confirmed extent hybridization within successful reconstructing paleogeography section.