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Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species

Authors :
Santiago C. González-Martínez
David Macaya-Sanz
Thelma Barbará
Léonie Suter
Christian Lexer
Jeffrey A. Joseph
N. Alba
Alex Widmer
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria = National Institute for Agricultural and Food Research and Technology (INIA)
Jodrell Laboratory
Royal Botanic Garden , Kew
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)
Department of Biology
Northern Arizona University [Flagstaff]
Source :
Repositorio de Resultados de Investigación del INIA, INIA: Repositorio de Resultados de Investigación del INIA, Heredity, Heredity, Nature Publishing Group, 2011, 107 (5), pp.478-86. ⟨10.1038/hdy.2011.35⟩, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria INIA
Publication Year :
2011
Publisher :
Springer Nature, 2011.

Abstract

Molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. Although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural F 1 's. Here, we used this approach to understand the genetics of post-mating isolation and barriers to introgression in Populus alba and Populus tremula, two ecologically divergent, hybridizing forest trees. We studied 86 interspecific backcross (BC 1) progeny and 350 individuals from natural populations of these species for up to 98 nuclear genetic markers, including microsatellites, indels and single nucleotide polymorphisms, and inferred the origin of the cytoplasm of the cross with plastid DNA. Genetic analysis of the BC 1 revealed extensive segregation distortions on six chromosomes, and 90% of these (12 out oF 13) favored P. tremula donor alleles in the heterospecific genomic background. Since selection was documented during early diploid stages of the progeny, this surprising result was attributed to epistasis, cyto-nuclear coadaptation, heterozygote advantage at nuclear loci experiencing introgression or a combination of these. Our results indicate that gene flow across porous species barriers affects these poplars and aspens beyond neutral, Mendelian expectations and suggests the mechanisms responsible. Contrary to expectations, the Populus sex determination region is not protected from introgression. Understanding the population dynamics of the Populus sex determination region will require tests based on natural interspecific hybrid zones. © 2011 Macmillan Publishers Limited All rights reserved.

Details

Language :
English
ISSN :
0018067X
Database :
OpenAIRE
Journal :
Repositorio de Resultados de Investigación del INIA, INIA: Repositorio de Resultados de Investigación del INIA, Heredity, Heredity, Nature Publishing Group, 2011, 107 (5), pp.478-86. ⟨10.1038/hdy.2011.35⟩, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria INIA
Accession number :
edsair.doi.dedup.....88014fdeeb52c851ad2788f7df8eac4b
Full Text :
https://doi.org/10.1038/hdy.2011.35⟩