Efficiently tracking selection in a multiparental population: the case of earliness in wheat

Stéphanie Thépot, Gwendal Restoux, Isabelle Goldringer, Frédéric Hospital, David Gouache, Ian Mackay, Jérôme Enjalbert

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Multiparental populations are innovative tools for fine mapping large numbers of loci. Here we explored the application of a wheat Multiparent Advanced Generation Inter-Cross (MAGIC) population for QTL mapping. This population was created by 12 generations of free recombination among 60 founder lines, following modification of the mating system from strict selfing to strict outcrossing using the ms1b nuclear male sterility gene. Available parents and a subset of 380 SSD lines of the resulting MAGIC population were phenotyped for earliness and genotyped with the 9K i-Select SNP array and additional markers in candidate genes controlling heading date. We demonstrated that 12 generations of strict outcrossing rapidly and drastically reduced linkage disequilibrium to very low levels even at short map distances and also greatly reduced the population structure exhibited among the parents. We developed a Bayesian method, based on allelic frequency, to estimate the contribution of each parent in the evolved population. To detect loci under selection and estimate selective pressure, we also developed a new method comparing shifts in allelic frequency between the initial and the evolved populations due to both selection and genetic drift with expectations under drift only. This evolutionary approach allowed us to identify 26 genomic areas under selection. Using association tests between flowering time and polymorphisms, 6 of these genomic areas appeared to carry flowering time QTL, 1 of which corresponds to Ppd-D1, a major gene involved in the photoperiod sensitivity. Frequency shifts at 4 of 6 areas were consistent with earlier flowering of the evolved population relative to the initial population. The use of this new outcrossing wheat population, mixing numerous initial parental lines through multiple generations of panmixia, is discussed in terms of power to detect genes under selection and association mapping. Furthermore we provide new statistical methods for use in future analyses of multiparental populations.
Original languageEnglish
Pages (from-to)609-623
JournalGenetics
Volume199
Early online date11 Nov 2014
DOIs
Publication statusPrint publication - 2015
Externally publishedYes

Fingerprint

Triticum
early development
wheat
Population
outcrossing
flowering
gene frequency
quantitative trait loci
Genes
genomics
Silver Sulfadiazine
loci
Genetic Drift
male fertility
Bayes Theorem
major genes
genetic drift
Bayesian theory
linkage disequilibrium
Male Infertility

Bibliographical note

Copyright © 2015 by the Genetics Society of America

Keywords

  • MAGIC
  • Photoperiod
  • wheat

Cite this

Thépot, S., Restoux, G., Goldringer, I., Hospital, F., Gouache, D., Mackay, I., & Enjalbert, J. (2015). Efficiently tracking selection in a multiparental population: the case of earliness in wheat. Genetics, 199, 609-623. https://doi.org/10.1534/genetics.114.169995
Thépot, Stéphanie ; Restoux, Gwendal ; Goldringer, Isabelle ; Hospital, Frédéric ; Gouache, David ; Mackay, Ian ; Enjalbert, Jérôme. / Efficiently tracking selection in a multiparental population: the case of earliness in wheat. In: Genetics. 2015 ; Vol. 199. pp. 609-623.
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Thépot, S, Restoux, G, Goldringer, I, Hospital, F, Gouache, D, Mackay, I & Enjalbert, J 2015, 'Efficiently tracking selection in a multiparental population: the case of earliness in wheat', Genetics, vol. 199, pp. 609-623. https://doi.org/10.1534/genetics.114.169995

Efficiently tracking selection in a multiparental population: the case of earliness in wheat. / Thépot, Stéphanie; Restoux, Gwendal; Goldringer, Isabelle; Hospital, Frédéric; Gouache, David; Mackay, Ian; Enjalbert, Jérôme.

In: Genetics, Vol. 199, 2015, p. 609-623.

Research output: Contribution to journalArticle

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AU - Thépot, Stéphanie

AU - Restoux, Gwendal

AU - Goldringer, Isabelle

AU - Hospital, Frédéric

AU - Gouache, David

AU - Mackay, Ian

AU - Enjalbert, Jérôme

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