Molecular phylogeny and systematics of the highly polymorphic Rumex bucephalophorus complex (Polygonaceae)

• Published in: Molecular phylogenetics and evolution 2011-12, Vol.61 (3), p.659-670
• Main Authors: Talavera, M., Balao, F., Casimiro-Soriguer, R., Ortiz, M.Á., Terrab, A., Arista, M., Ortiz, P.L., Stuessy, T.F., Talavera, S.
• Format: Article
• Language: English
• Subjects: AFLP; amplified fragment length polymorphism; Amplified Fragment Length Polymorphism Analysis; Bayes Theorem; Bayesian population analysis; Cell Nucleus - genetics; Classification; Cluster Analysis; Diaspore; Diaspore traits; Divergence; DNA, Intergenic - genetics; DNA, Plant - genetics; Evolution; genetic markers; Genetics, Population; Geography; internal transcribed spacers; ITS; Macaronesian area; Markers; Mediterranean Basin; Molecular Sequence Data; monophyly; Morocco; Phylogeny; Polymorphism, Genetic; Principal Component Analysis; Rumex; Rumex - classification; Rumex - genetics; Salinity; Seed Dispersal - genetics; Spain; Subgroups; VAR
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2011.08.005

[Display omitted] ► R. bucephalophorus forms a monophyletic group. ► Their diversification began around 4.2Mya, at the end of Messinian crisis. ► Subsp. bucephalophorus is sister to all of subspecies. ► Subsp. canariensis is the most recently derived subspecific taxon. ► Subspecies hispanicus and subsp. gallicus constitute a single group. Rumex bucephalophorus is a very polymorphic species that has been subjected to various taxonomic studies in which diverse infraspecific taxa have been recognised on the basis of diaspore traits. In this study we used molecular markers (ITS and AFLP) to explore this remarkable diversity, to test previous hypotheses of classification, and attempt to explain biogeographic patterns. Results show that R. bucephalophorus forms a monophyletic group in which diversification began around 4.2Mya, at the end of Messinian Salinity Crisis. The two molecular markers clearly show a deep divergence separating subsp. bucephalophorus from all other subspecific taxa, among which subsp. canariensis also constitutes a separate and well distinguishable unit. In contrast, subspecies hispanicus and subsp. gallicus constitute a monophyletic group in which three subgroups can be recognised: subsp. hispanicus, subsp. gallicus var. gallicus and subsp. gallicus var. subaegeus. However, these three subgroups are not clearly distinguished genetically or morphologically, so that in formal classification it would be preferable to treat them at the varietal level.