title: How just a few makes a lot: Speciation via reticulation and apomixis on example of European brambles (Rubus subgen. Rubus, Rosaceae).
abstract: New species are generated by many means, among which hybridization plays an important role. Interspecific hybrids can form isolated evolutionary units, especially when mechanisms increasing viability and fertility, like polyploidy and apomixis, are involved. A good model system to study reticulate evolution in plants is Rubus subgen. Rubus (brambles, blackberries), which only in Europe includes 748 accepted species, out of which only four are sexual diploids and all others are polyploid apomicts. We employed two molecular markers (ITS and cpDNA) to shed light on the evolutionary history of European bramble flora and main processes generating such high species diversity. We distinguished just six ancestral diploids (including two extinct ones) for both markers, which gave rise to all European polyploid accessions, and revealed an extreme reticulation in bramble evolution. We furthermore detected hybridogenous origins and identified putative parents for several taxa (e.g. ser. Nessenses), while in other groups (e.g. ser. Discolores) we could also infer the direction of hybridization. By comparing different cp haplotypes having clear geographic patterns, we hypothesize that the origin of European brambles can be attributed to both Holocene species range expansion and Pleistocene climate fluctuations.
authors.affiliation: Department of Botany, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 11, 78371 Olomouc, Czech Republic. Electronic address: michal.sochor@volny.cz.
authors.forename: Michal
authors.initials: M
authors.lastname: Sochor
authors.affiliation: Department of Botany, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 11, 78371 Olomouc, Czech Republic.
authors.forename: Radim J
authors.initials: RJ
authors.lastname: Vašut
authors.affiliation: Apomixis Research Group, Leibnitz Institute of Plant Genetics and Crop Research (IPK), Corrensstr. 3, 06466 Gatersleben, Germany.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Sharbel
authors.affiliation: Department of Botany, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 11, 78371 Olomouc, Czech Republic.
authors.forename: Bohumil
authors.initials: B
authors.lastname: Trávníček
mesh_terms: D060832:Apomixis / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004171:Diploidy; D005060:Europe; D019143:Evolution, Molecular; D005819:Genetic Markers / Q000235:genetics; D049810:Genetic Speciation; D006824:Hybridization, Genetic / Q000235:genetics; D046448:Ice Cover; D008957:Models, Genetic; D010802:Phylogeny; D011123:Polyploidy; D065856:Rubus / Q000145:classification / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D018742:DNA, Chloroplast; D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers
keywords: Agamospermy; Brambles; Concerted evolution; Hybridization; Phylogeny; Rubus