Mating system impacts the genetic architecture of adaptation to heterogeneous environments

Kathryn A. Hodgins, Sam Yeaman

Research output: Contribution to journalArticleResearchpeer-review

8 Citations (Scopus)


Self-fertilisation has consequences for variation across the genome as it reduces effective population size, effect recombination rates and pollen flow, with implications for local adaptation. We conducted simulations of divergent stabilising selection on a quantitative trait with drift, pollen flow, mutation, recombination and different outcrossing rates. We quantified trait divergence and the genetic architecture of adaptation. We conducted an FST outlier analysis to identify candidate loci and quantified the impact of mating system on detectability. Selfing promoted trait divergence mainly through reductions in pollen flow. Moreover, trait architecture became more diffuse with selfing. Average effect size of trait loci was lower, while the number of loci, and their clustering distance increased. The genetic architecture of selfers was also more diffuse than outcrossers for equivalent migration rates. However, when deleterious alleles were included, architectures became more concentrated in selfers, likely to be because of reductions in population size caused by mutational meltdown and impacts of background selection on Ne. Our simulations demonstrate that mating system has important impacts on adaptive divergence of traits and the genetic landscape underlying that divergence. Selfing has a significant effect on detectability of regions of the genome important for adaptation because of neutral divergence and diffuse trait architecture.

Original languageEnglish
Pages (from-to)1201-1214
Number of pages14
JournalNew Phytologist
Issue number3
Publication statusPublished - 1 Nov 2019


  • F outlier tests
  • genetic architecture
  • genomic islands of divergence
  • local adaptation
  • mating system
  • migration–selection balance
  • quantitative trait loci
  • self-fertilisation

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