RT Journal Article
SR Electronic
T1 Massive haplotypes underlie ecotypic differentiation in sunflowers
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 790279
DO 10.1101/790279
A1 Todesco, Marco
A1 Owens, Gregory L.
A1 Bercovich, Natalia
A1 Légaré, Jean-Sébastien
A1 Soudi, Shaghayegh
A1 Burge, Dylan O.
A1 Huang, Kaichi
A1 Ostevik, Katherine L.
A1 Drummond, Emily B. M.
A1 Imerovski, Ivana
A1 Lande, Kathryn
A1 Pascual, Mariana A.
A1 Cheung, Winnie
A1 Staton, S. Evan
A1 Muños, Stéphane
A1 Nielsen, Rasmus
A1 Donovan, Lisa A.
A1 Burke, John M.
A1 Yeaman, Sam
A1 Rieseberg, Loren H.
YR 2019
UL http://biorxiv.org/content/early/2019/10/02/790279.abstract
AB Species often include multiple ecotypes that are adapted to different environments. But how do ecotypes arise, and how are their distinctive combinations of adaptive alleles maintained despite hybridization with non-adapted populations? Re-sequencing of 1506 wild sunflowers from three species identified 37 large (1-100 Mbp), non-recombining haplotype blocks associated with numerous ecologically relevant traits, and soil and climate characteristics. Limited recombination in these regions keeps adaptive alleles together, and we find that they differentiate several sunflower ecotypes; for example, they control a 77 day difference in flowering between ecotypes of silverleaf sunflower (likely through deletion of a FLOWERING LOCUS T homolog), and are associated with seed size, flowering time and soil fertility in dune-adapted sunflowers. These haplotypes are highly divergent, associated with polymorphic structural variants, and often appear to represent introgressions from other, possibly extinct, congeners. This work highlights a pervasive role of structural variation in maintaining complex ecotypic adaptation.