Reticulation or divergence: the origin of a rare serpentine endemic assessed with chloroplast, nuclear and RAPD markers

Species of Armeria from the southern part of the Iberian Peninsula have been postulated to undergo extensive reticulate evolution based on ITS sequences as well as morphometric, eco-geographical evidence and crossing experiments. The hypothesis that a rare serpentine endemic (A. villosa subsp. carratracensis) originated from a cross between another serpentine tolerant endemic (A. colorata) and a widespread limestone species (A. villosa subsp. longiaristata) is tested with molecular markers. Sequences from two chloroplast regions [trnL (UAA)-trnF (GAA) and trnD (GUC)-trnT (GGU)], from nuclear ribosomal DNA (ITS-1 + 5.8S + ITS-2) as well as RAPD data are used. Variation in chloroplast and nuc…