Molecular phylogenetic analyses identify Alpine differentiation and dysploid chromosome number changes as major forces for the evolution of the European endemic Phyteuma (Campanulaceae)

• Published in: Molecular phylogenetics and evolution Vol. 69; no. 3; pp. 634 - 652
• Main Authors: Schneeweiss, Gerald M., Pachschwöll, Clemens, Tribsch, Andreas, Schönswetter, Peter, Barfuss, Michael H.J., Esfeld, Korinna, Weiss-Schneeweiss, Hanna, Thiv, Mike
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2013
• Subjects: Alps; amplified fragment length polymorphism; Amplified Fragment Length Polymorphism Analysis; Bayes Theorem; Biogeography; Campanulaceae; Campanulaceae - classification; Campanulaceae - genetics; Cell Nucleus - genetics; chromosome number; Chromosome number evolution; Chromosomes; Chromosomes, Plant - genetics; Differentiation; DNA, Plant - genetics; Ecology; Evolution; Evolution, Molecular; Fingerprints; flowers; Karyotype; Likelihood Functions; Models, Genetic; monophyly; Phylogeny; Physoplexis; Phyteuma; Plastids - genetics; Recognition; Sampling; Sequence Analysis, DNA; species diversity; taxonomy; Alps region; Biogeography; Phylogeny; Phyteuma; Campanulaceae; Physoplexis; Chromosome number evolution
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2013.07.015

[Display omitted] •A densely sampled phylogeny of Phyteuma (Campanulaceae) is reconstructed.•Phyteuma is monophyletic and contains two main clades.•Distinctness of the currently recognized species is mostly corroborated.•Dysploidy, allopatric and ecological differentiation drive species differentiation. Phyteuma is a chromosomally and ecologically diverse vascular plant genus and constitutes an excellent system for studying both the role of chromosomal change for species diversification and the evolution of high-mountain biota. This kind of research is, however, hampered by the lack of a sound phylogenetic framework exacerbated by the notoriously low predictive power of traditional taxonomy with respect to phylogenetic relationships in Campanulaceae. Based on a comprehensive taxon sampling and analyses of nuclear and plastid sequence and AFLP fingerprint data, Phyteuma is confirmed as a monophyletic group sister to the monotypic Physoplexis, which is in line with their peculiar flower morphologies. Within Phyteuma two clades, largely corresponding to previously recognized sections, are consistently found. The traditional circumscription of taxonomic series is largely rejected. Whereas distinctness of the currently recognized species is mostly corroborated, some interspecific relationships remain ambiguous due to incongruences between nuclear and plastid data. Major forces for diversification and evolution of Phyteuma are descending dysploidy (i.e., a decrease in chromosome base number) as well as allopatric and ecological differentiation within the Alps, the genus’ center of species diversity.