Open Collections

Whitney, Kenneth D.; Broman, Karl W.; Kane, Nolan C.; Hovick, Stephen M.; Randell, Rebecca A.; Rieseberg, Loren H.

<b>Abstract</b><br/>The wild North American sunflowers Helianthus annuus and H. debilis are participants in one of the earliest identified examples of adaptive trait introgression, and the exchange is hypothesized to have triggered a range expansion in H. annuus. However, the genetic basis of the adaptive exchange has not been examined. Here, we combine quantitative trait locus (QTL) mapping with field measurements of fitness to identify candidate H. debilis QTL alleles likely to have introgressed into H. annuus to form the natural hybrid lineage H. a. texanus. Two 500-individual BC1 mapping populations were grown in central Texas, genotyped for 384 single nucleotide polymorphism (SNP) markers and then phenotyped in the field for two fitness and 22 herbivore resistance, ecophysiological, phenological and architectural traits. We identified a total of 110 QTL, including at least one QTL for 22 of the 24 traits. Over 75% of traits exhibited at least one H. debilis QTL allele that would shift the trait in the direction of the wild hybrid H. a. texanus. We identified three chromosomal regions where H. debilis alleles increased both female and male components of fitness; these regions are expected to be strongly favoured in the wild. QTL for a number of other ecophysiological, phenological and architectural traits colocalized with these three regions and are candidates for the actual traits driving adaptive shifts. G × E interactions played a modest role, with 17% of the QTL showing potentially divergent phenotypic effects between the two field sites. The candidate adaptive chromosomal regions identified here serve as explicit hypotheses for how the genetic architecture of the hybrid lineage came into existence.; <b>Usage notes</b><br /><div class="o-metadata__file-usage-entry"><h4 class="o-heading__level3-file-title">Phenotype and SNP Genotype Data</h4><div class="o-metadata__file-description">This Excel file contains information on 906 field-grown backcross1 sunflower plants. Field site is identified in column Z. Plants are identified by the number in column AA. Columns A-Y contain field-measured trait data. Trait names correspond to the abbreviations in Table 1 of the associated manuscript. Columns AH - HO contain SNP genotype data; A = H. a. annuus allele; D = H. debilis allele.</div><div class="o-metadata__file-name">Whitney phenotype genotype data.xlsx</br></div></div><div class="o-metadata__file-usage-entry"><h4 class="o-heading__level3-file-title">Linkage Map</h4><div class="o-metadata__file-description">This Excel file contains the estimated linkage map for the H. a. annuus x H. debilis backcross1 mapping populations. The position of each marker on the linkage group is given in centiMorgans (cM).</div><div class="o-metadata__file-name">Whitney linkage map.xlsx</br></div></div>

Texas; North America

Dryad version number: 1</p>

Version status: submitted</p>

Dryad curation status: Published</p>

Sharing link: https://datadryad.org/stash/share/oJ_ikB6amCnp2e70u8rWA4_TrHjMfUgSCD9wn_nVeDg</p>

Storage size: 904363</p>

Visibility: public</p>

University of British Columbia Library

10.14288/1.0397698

https://doi.org/10.5683/SP2/GFIJZ1; https://doi.org/10.5061/dryad.5dh5f

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