title: The Double-Reduction Landscape in Tetraploid Potato as Revealed by a High-Density Linkage Map.
abstract: The creation of genetic linkage maps in polyploid species has been a long-standing problem for which various approaches have been proposed. In the case of autopolyploids, a commonly used simplification is that random bivalents form during meiosis. This leads to relatively straightforward estimation of recombination frequencies using maximum likelihood, from which a genetic map can be derived. However, autopolyploids such as tetraploid potato (Solanum tuberosum L.) may exhibit additional features, such as double reduction, not normally encountered in diploid or allopolyploid species. In this study, we produced a high-density linkage map of tetraploid potato and used it to identify regions of double reduction in a biparental mapping population. The frequency of multivalents required to produce this degree of double reduction was determined through simulation. We also determined the effect that multivalents or preferential pairing between homologous chromosomes has on linkage mapping. Low levels of multivalents or preferential pairing do not adversely affect map construction when highly informative marker types and phases are used. We reveal the double-reduction landscape in tetraploid potato, clearly showing that this phenomenon increases with distance from the centromeres.
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen 6708 PB, The Netherlands.
authors.forename: Peter M
authors.identifier: http://orcid.org/0000-0002-0665-6508
authors.initials: PM
authors.lastname: Bourke
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen 6708 PB, The Netherlands.
authors.forename: Roeland E
authors.identifier: http://orcid.org/0000-0003-4388-9244
authors.initials: RE
authors.lastname: Voorrips
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen 6708 PB, The Netherlands.
authors.forename: Richard G F
authors.initials: RG
authors.lastname: Visser
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen 6708 PB, The Netherlands chris.maliepaard@wur.nl.
authors.forename: Chris
authors.initials: C
authors.lastname: Maliepaard
mesh_terms: D002503:Centromere; D002874:Chromosome Mapping; D023902:Chromosome Pairing; D003198:Computer Simulation; D005819:Genetic Markers; D011995:Recombination, Genetic; D011198:Solanum tuberosum / Q000166:cytology / Q000235:genetics*; D057891:Tetraploidy
chemical_list: D005819:Genetic Markers
keywords: double reduction; linkage mapping; multivalents; potato; tetraploid