Huang, Kaichi

Andrew, Rose L

Owens, Gregory L

Ostevik, Kate L

Rieseberg, Loren H

2020-07

Both models and case studies suggest that chromosomal inversions can facilitate adaptation and speciation in the presence of gene flow by suppressing recombination between locally adapted alleles. Until recently, however, it has been laborious and time-consuming to identify and genotype inversions in natural populations. Here we apply RAD sequencing data and newly developed population genomic approaches to identify putative inversions that differentiate a sand dune ecotype of the prairie sunflower (<I>Helianthus petiolaris</I>) from populations found on the adjacent sand sheet. We detected seven large genomic regions that exhibit a different population structure than the rest of the genome and that vary in frequency between dune and nondune populations. These regions also show high linkage disequilibrium and high heterozygosity between, but not within, arrangements, consistent with the behaviour of large inversions, an inference subsequently validated in part by comparative genetic mapping. Genome-environment association analyses show that key environmental variables, including vegetation cover and soil nitrogen, are significantly associated with inversions. The inversions colocate with previously described "islands of differentiation," and appear to play an important role in adaptive divergence and incipient speciation within <I>H. petiolaris</I>.

Molecular Ecology, 29(14), p. 2535-2549

1365-294X

0962-1083

32246540

https://hdl.handle.net/1959.11/30396

en

Wiley-Blackwell Publishing Ltd

Multiple chromosomal inversions contribute to adaptive divergence of a dune sunflower ecotype

Journal Article

Publication