title: Combined linkage and association mapping of flowering time in Sunflower (Helianthus annuus L.).
abstract: Association mapping and linkage mapping were used to identify quantitative trait loci (QTL) and/or causative mutations involved in the control of flowering time in cultivated sunflower Helianthus annuus. A panel of 384 inbred lines was phenotyped through testcrosses with two tester inbred lines across 15 location × year combinations. A recombinant inbred line (RIL) population comprising 273 lines was phenotyped both per se and through testcrosses with one or two testers in 16 location × year combinations. In the association mapping approach, kinship estimation using 5,923 single nucleotide polymorphisms was found to be the best covariate to correct for effects of panel structure. Linkage disequilibrium decay ranged from 0.08 to 0.26 cM for a threshold of 0.20, after correcting for structure effects, depending on the linkage group (LG) and the ancestry of inbred lines. A possible hitchhiking effect is hypothesized for LG10 and LG08. A total of 11 regions across 10 LGs were found to be associated with flowering time, and QTLs were mapped on 11 LGs in the RIL population. Whereas eight regions were demonstrated to be common between the two approaches, the linkage disequilibrium approach did not detect a documented QTL that was confirmed using the linkage mapping approach.
authors: Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, UMR441, 31326 Castanet-Tolosan, France. elena.cadic@toulouse.inra.fr
authors: Elena
authors: E
authors: Cadic
authors: Marie
authors: M
authors: Coque
authors: Felicity
authors: F
authors: Vear
authors: Bruno
authors: B
authors: Grezes-Besset
authors: Jerôme
authors: J
authors: Pauquet
authors: Joël
authors: J
authors: Piquemal
authors: Yannick
authors: Y
authors: Lippi
authors: Philippe
authors: P
authors: Blanchard
authors: Michel
authors: M
authors: Romestant
authors: Nicolas
authors: N
authors: Pouilly
authors: David
authors: D
authors: Rengel
authors: Jerôme
authors: J
authors: Gouzy
authors: Nicolas
authors: N
authors: Langlade
authors: Brigitte
authors: B
authors: Mangin
authors: Patrick
authors: P
authors: Vincourt
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000502:physiology*; D017343:Genes, Plant / Q000235:genetics*; D008040:Genetic Linkage; D005819:Genetic Markers; D006368:Helianthus / Q000235:genetics* / Q000254:growth & development; D015810:Linkage Disequilibrium; D010641:Phenotype; D040641:Quantitative Trait Loci
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers