Fine mapping and haplotype structure analysis of a major flowering time quantitative trait locus on maize chromosome 10.
Flowering time is a major adaptive trait in plants and an important selection criterion for crop species. In maize, however, little is known about its molecular basis. In this study, we report the fine mapping and characterization of a major quantitative trait locus located on maize chromosome 10, which regulates flowering time through photoperiod sensitivity. This study was performed in near-isogenic material derived from a cross between the day-neutral European flint inbred line FV286 and the tropical short-day inbred line FV331. Recombinant individuals were identified among a large segregating population and their progenies were scored for flowering time. Combined genotypic characterization led to delimit the QTL to an interval of 170 kb and highlighted an unbalanced recombination pattern. Two bacterial artificial chromosomes (BACs) covering the region were analyzed to identify putative candidate genes, and synteny with rice, sorghum, and brachypodium was investigated. A gene encoding a CCT domain protein homologous to the rice Ghd7 heading date regulator was identified, but its causative role was not demonstrated and deserves further analyses. Finally, an association study showed a strong level of linkage disequilibrium over the region and highlighted haplotypes that could provide useful information for the exploitation of genetic resources and marker-assisted selection in maize.
Ducrocq
Sébastien
S
Institut National de la Recherche Agronomique (INRA)/Université Paris-Sud, Centre National de la Recherche Scientifique (CNRS), AgroParisTech, Unité Mixte de Recherche (UMR) de Génétique Végétale, Ferme du Moulon, France.
Giauffret
Catherine
C
Madur
Delphine
D
Combes
Valérie
V
Dumas
Fabrice
F
Jouanne
Sophie
S
Coubriche
Denis
D
Jamin
Philippe
P
Moreau
Laurence
L
Charcosset
Alain
A
D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D035264:Flowers / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D006239:Haplotypes; D008969:Molecular Sequence Data; D040641:Quantitative Trait Loci; D015203:Reproducibility of Results; D026801:Synteny; D013997:Time Factors; D003313:Zea mays / Q000235:genetics*