title: Recreating Stable Brachypodium hybridum Allotetraploids by Uniting the Divergent Genomes of B. distachyon and B. stacei.
abstract: Brachypodium hybridum (2n = 30) is a natural allopolyploid with highly divergent sub-genomes derived from two extant diploid species, B. distachyon (2n = 10) and B. stacei (2n = 20) that differ in chromosome evolution and number. We created synthetic B. hybridum allotetraploids by hybridizing various lines of B. distachyon and B. stacei. The initial amphihaploid F1 interspecific hybrids were obtained at low frequencies when B. distachyon was used as the maternal parent (0.15% or 0.245% depending on the line used) and were sterile. No hybrids were obtained from reciprocal crosses or when autotetraploids of the parental species were crossed. Colchicine treatment was used to double the genome of the F1 amphihaploid lines leading to allotetraploids. The genome-doubled F1 plants produced a few S1 (first selfed generation) seeds after self-pollination. S1 plants from one parental combination (Bd3-1×Bsta5) were fertile and gave rise to further generations whereas those of another parental combination (Bd21×ABR114) were sterile, illustrating the importance of the parental lineages crossed. The synthetic allotetraploids were stable and resembled the natural B. hybridum at the phenotypic, cytogenetic and genomic levels. The successful creation of synthetic B. hybridum offers the possibility to study changes in genome structure and regulation at the earliest stages of allopolyploid formation in comparison with the parental species and natural B. hybridum.
authors.affiliation: Organization and evolution of complex genomes, Institut National de la Recherche agronomique, Université d'Evry Val d'Essonne, Evry, France.
authors.forename: Vinh Ha
authors.initials: VH
authors.lastname: Dinh Thi
authors.affiliation: Unité Mixte de Recherches INRA, Agrocampus Rennes-Université Rennes 1, Institut de Génétique, Environnement et Protection des Plantes, Le Rheu, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Coriton
authors.affiliation: Organization and evolution of complex genomes, Institut National de la Recherche agronomique, Université d'Evry Val d'Essonne, Evry, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Le Clainche
authors.affiliation: Organization and evolution of complex genomes, Institut National de la Recherche agronomique, Université d'Evry Val d'Essonne, Evry, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Arnaud
authors.affiliation: DOE Joint Genome Institute, Walnut Creek, United States of America.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Gordon
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences,Martonvásár, Brunszvik u 2, Hungary.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Linc
authors.affiliation: Department of Agriculture and Environmental Sciences, High Polytechnic School of Huesca, University of Zaragoza, Huesca, Spain.|Department of Botany, Institute of Biology, Tomsk State University, Tomsk, Russia.
authors.forename: Pilar
authors.initials: P
authors.lastname: Catalan
authors.affiliation: Department of Plant Anatomy and Cytology, Faculty of Biology and Environmental Protection, University of Silesia,Katowice, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Hasterok
authors.affiliation: DOE Joint Genome Institute, Walnut Creek, United States of America.|Department of Plant and Microbial Biology, University of California, Berkeley, United States of America.
authors.forename: John P
authors.initials: JP
authors.lastname: Vogel
authors.affiliation: Unité Mixte de Recherches INRA, Agrocampus Rennes-Université Rennes 1, Institut de Génétique, Environnement et Protection des Plantes, Le Rheu, France.
authors.forename: Joseph
authors.initials: J
authors.lastname: Jahier
authors.affiliation: Organization and evolution of complex genomes, Institut National de la Recherche agronomique, Université d'Evry Val d'Essonne, Evry, France.|Institute of System and Synthetic Biology, Genopole, Centre National de la Recherche Scientifique, Université d'Evry Val d'Essonne, Université Paris-Saclay, Evry, France.
authors.forename: Boulos
authors.initials: B
authors.lastname: Chalhoub
mesh_terms: D058431:Brachypodium / Q000145:classification / Q000235:genetics*; D032461:Chromosomes, Plant / Q000187:drug effects / Q000235:genetics; D003078:Colchicine / Q000494:pharmacology; D004171:Diploidy; D005818:Genetic Engineering / Q000379:methods; D014644:Genetic Variation; D018745:Genome, Plant / Q000235:genetics*; D008957:Models, Genetic; D010641:Phenotype; D000069600:Plant Breeding / Q000379:methods*; D015203:Reproducibility of Results; D013045:Species Specificity; D057891:Tetraploidy; D050257:Tubulin Modulators / Q000494:pharmacology
chemical_list: D050257:Tubulin Modulators; D003078:Colchicine