Originally published as Genetics Published Articles Ahead of Print on June 11, 2007.
Genetics, Vol. 176, 2589-2599, August 2007, Copyright © 2007
doi:10.1534/genetics.107.075333
Quantitative Trait Locus Analysis of the Early Domestication of Sunflower
David M. Wills and
John M. Burke1
Department of Plant Biology, University of Georgia, Athens, Georgia 30602
1 Corresponding author: Department of Plant Biology, Miller Plant Sciences Bldg., Athens, GA 30602.
E-mail: jmburke{at}uga.edu
Genetic analyses of the domestication syndrome have revealed that domestication-related traits typically have a very similar genetic architecture across most crops, being conditioned by a small number of quantitative trait loci (QTL), each with a relatively large effect on the phenotype. To date, the domestication of sunflower (Helianthus annuus L.) stands as the only counterexample to this pattern. In previous work involving a cross between wild sunflower (also H. annuus) and a highly improved oilseed cultivar, we found that domestication-related traits in sunflower are controlled by numerous QTL, typically of small effect. To provide insight into the minimum genetic changes required to transform the weedy common sunflower into a useful crop plant, we mapped QTL underlying domestication-related traits in a cross between a wild sunflower and a primitive Native American landrace that has not been the target of modern breeding programs. Consistent with the results of the previous study, our data indicate that the domestication of sunflower was driven by selection on a large number of loci, most of which had small to moderate phenotypic effects. Unlike the results of the previous study, however, nearly all of the QTL identified herein had phenotypic effects in the expected direction, with the domesticated allele producing a more crop-like phenotype and the wild allele producing a more wild-like phenotype. Taken together, these results are consistent with the hypothesis that selection during the post-domestication era has resulted in the introduction of apparently maladaptive alleles into the modern sunflower gene pool.
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Molecular insights into the evolution of crop plants
Am. J. Botany,
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95(2):
113 - 122.
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Copyright © 2007 by the Genetics Society of America.