title: Tracking the evolutionary history of polyploidy in Fragaria L. (strawberry): new insights from phylogenetic analyses of low-copy nuclear genes.
abstract: Phylogenetic utility of two nuclear genes (GBSSI-2 and DHAR) was explored in genus Fragaria in order to clarify phylogenetic relationships among taxa and to elucidate the origin of the polyploid species. Orthology of the amplified products was assessed by several methods. Our results strongly suggest the loss of one GBSSI duplicated copy (GBSSI-1) in the Fragariinae subtribe. Phylogenetic analyses provided new insights into the evolutionary history of Fragaria, such as evidence supporting the presence of three main diploid genomic pools in the genus and demonstrating the occurrence of independent events of polyploidisation. In addition, the data provide evidence supporting an allopolyploid origin of the hexaploid F. moschata, and the octoploids F. chiloensis, F. iturupensis and F. virginiana. Accordingly, a new pattern summarizing our present knowledge on the Fragaria evolutionary history is proposed. Additionally, sequence analyses also revealed relaxed constraints on homoeologous copies at high ploidy level, as demonstrated by deletion events within DHAR coding sequences of some allo-octoploid haplotypes.
authors.affiliation: INRA, UR 419, Unité de Recherche sur les Espèces Fruitières, Domaine de la Grande Ferrade, Villenave d'Ornon, France.
authors.forename: M
authors.initials: M
authors.lastname: Rousseau-Gueutin
authors.forename: A
authors.initials: A
authors.lastname: Gaston
authors.forename: A
authors.initials: A
authors.lastname: Aïnouche
authors.forename: M L
authors.initials: ML
authors.lastname: Aïnouche
authors.forename: K
authors.initials: K
authors.lastname: Olbricht
authors.forename: G
authors.initials: G
authors.lastname: Staudt
authors.forename: L
authors.initials: L
authors.lastname: Richard
authors.forename: B
authors.initials: B
authors.lastname: Denoyes-Rothan
mesh_terms: D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D004171:Diploidy; D019143:Evolution, Molecular; D031985:Fragaria / Q000145:classification / Q000235:genetics*; D017343:Genes, Plant; D018745:Genome, Plant; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D011123:Polyploidy; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013214:Starch Synthase / Q000235:genetics
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; C060756:waxy protein, plant; D010088:Oxidoreductases; C020666:glutathione dehydrogenase (ascorbate); D013214:Starch Synthase