Major ecological transitions in wild sunflowers facilitated by hybridization.
Hybridization is frequent in many organismal groups, but its role in adaptation is poorly understood. In sunflowers, species found in the most extreme habitats are ancient hybrids, and new gene combinations generated by hybridization are speculated to have contributed to ecological divergence. This possibility was tested through phenotypic and genomic comparisons of ancient and synthetic hybrids. Most trait differences in ancient hybrids could be recreated by complementary gene action in synthetic hybrids and were favored by selection. The same combinations of parental chromosomal segments required to generate extreme phenotypes in synthetic hybrids also occurred in ancient hybrids. Thus, hybridization facilitated ecological divergence in sunflowers.
Rieseberg
Loren H
LH
Department of Biology, Indiana University, Bloomington, IN 47405, USA. lriesebe@indiana.edu
Raymond
Olivier
O
Rosenthal
David M
DM
Lai
Zhao
Z
Livingstone
Kevin
K
Nakazato
Takuya
T
Durphy
Jennifer L
JL
Schwarzbach
Andrea E
AE
Donovan
Lisa A
LA
Lexer
Christian
C
D000222:Adaptation, Physiological; D005075:Biological Evolution; D002874:Chromosome Mapping; D004171:Diploidy; D017753:Ecosystem; D004777:Environment; D017343:Genes, Plant; D018745:Genome, Plant; D005838:Genotype; D006368:Helianthus / Q000235:genetics* / Q000502:physiology; D006824:Hybridization, Genetic; D018895:Microsatellite Repeats; D009154:Mutation; D010641:Phenotype; D040641:Quantitative Trait Loci; D012641:Selection, Genetic; D013045:Species Specificity; D014481:United States