Premium
Genome scans reveal candidate domestication and improvement genes in cultivated sunflower, as well as post‐domestication introgression with wild relatives
Author(s) -
Baute Gregory J.,
Kane Nolan C.,
Grassa Christopher J.,
Lai Zhao,
Rieseberg Loren H.
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13255
Subject(s) - domestication , introgression , biology , helianthus annuus , helianthus , sunflower , genome , candidate gene , quantitative trait locus , genetics , gene , evolutionary biology , horticulture
Summary The development of modern crops typically involves both selection and hybridization, but to date most studies have focused on the former. In the present study, we explore how both processes, and their interactions, have molded the genome of the cultivated sunflower ( Helianthus annuus ), a globally important oilseed. To identify genes targeted by selection during the domestication and improvement of sunflower, and to detect post‐domestication hybridization with wild species, we analyzed transcriptome sequences of 80 genotypes, including wild, landrace, and modern lines of H. annuus , as well as two cross‐compatible wild relatives, Helianthus argophyllus and Helianthus petiolaris . Outlier analyses identified 122 and 15 candidate genes associated with domestication and improvement, respectively. As in several previous studies, genes putatively involved in oil biosynthesis were the most extreme outliers. Additionally, several promising associations were observed with previously mapped quantitative trait loci ( QTL s), such as branching. Admixture analyses revealed that all the modern cultivar genomes we examined contained one or more introgressions from wild populations, with every chromosome having evidence of introgression in at least one modern line. Cumulatively, introgressions cover c . 10% of the cultivated sunflower genome. Surprisingly, introgressions do not avoid candidate domestication genes, probably because of the reintroduction of branching.