IMR Press / FBL / Volume 26 / Issue 12 / DOI: 10.52586/5049
Open Access Original Research
Genome-wide signatures in flax pinpoint to adaptive evolution along its ecological gradient
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1 Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
2 Department of Agriculture and Agri-Food, Ottawa Research and Development Center, Ottawa, ON K1A 0C6, Canada
3 Aquatic and Crop Resource Development Research Centre, National Research Council of Canada, Saskatoon, SK S7N 5C2, Canada
*Correspondence: (Sylvie Cloutier)
Academic Editor: Changsoo Kim
Front. Biosci. (Landmark Ed) 2021, 26(12), 1559–1571;
Submitted: 19 August 2021 | Revised: 11 November 2021 | Accepted: 22 November 2021 | Published: 30 December 2021
(This article belongs to the Special Issue Leveraging Ecological and Genomic Signatures of Polygenic Adaptation)
Copyright: © 2021 The Author(s). Published by BRI.
This is an open access article under the CC BY 4.0 license (

Background: Flax is one of the eight founder crops of agriculture. It is believed to have been domesticated as a long-day plant that has since spread to survive in a wide range of eco-geographic regions extending from the warm Indian subcontinent to the low latitude east African highlands and to the cool and high-latitude Eurasia. Understanding the genetic basis underlying its adaptation and selection events throughout its dispersion is essential to develop cultivars adapted to local environmental conditions. Methods: Here we detected genetic signatures of local adaptation and selection events of flax based on 385 accessions from all major flax growing regions of the world using genome scan methods and three genomic datasets: (1) a genome-wide dataset of more than 275K single nucleotide polymorphisms (SNPs), (2) a filtered dataset of 23K SNPs with minor allele frequency >10% and, (3) a 34K exon-derived SNP dataset. Results: Principal component (PC) and fixation index (FST)-based genome scans yielded consistent outlier SNP loci on chromosomes 1, 8, 9 and 12. Additional loci on chromosomes 3, 7, 8, 10, 11, 13 and 14 were detected using both the PC and FST methods in two of the three datasets. A genome-environment association (GEA) analysis using the 23K dataset and the first PC of cropping season temperature, day-length and latitude identified significant SNPs on chromosomes 3, 7, 9 and 13. Conclusions: Most of the loci detected by the three methods harbored relevant genes for local adaptation, including some that play roles in day-length, light and other biotic and abiotic stresses responses. Such genetic signatures may help to select pre-breeding materials potentially adapted to specific growing niches prior to field performance trials. Given the current low genotyping cost and freely available environmental data, the genome scans along with GEA can readily provide opportunity to sort out materials suitable to various environmental conditions from large set of germplasm in gene banks and/or in situ, thereby assisting the breeding and genetic conservation efforts.

Principal component
Adaptive loci
Genetic signatures
Candidate genes
Fig. 1.
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