Genome-wide association mapping of flowering time inArabidopsis thalianain nature: genetics for underlying components and reaction norms across two successive years.
Often used as a proxy for the transition to reproduction, flowering time (FT) is an integrative trait of two successive biological processes,i.e.bolting time (BT) and the interval between bolting and flowering time (INT). In this study, we aimed to identify candidate genes associated with these composite traits inArabidopsis thalianausing a field experiment. Genome-wide association (GWA) mapping was performed on BT, INT and FT based on a sample of 179 worldwide natural accessions genotyped for 216,509 SNPs. The high resolution conferred by GWA mapping indicates that FT is an integrative trait at the genetic level, with distinct genetics for BT and INT. BT is shaped largely by genes involved in the circadian clock whereas INT is shaped by genes involved in both the hormone pathways and cold acclimation. Finally, the florigenTSFappears to be the main integrator of environmental and internal signals in ecologically realistic conditions. Based on FT scored in a previous field experiment, we also studied the genetics underlying reaction norms across two years. Only four genes were common to both years, emphasizing the need to repeat field experiments. The gene regulation model appeared as the main genetic model for genotype × year interactions.
Laboratoire Génétique et Evolution des Populations Végétales, UMR CNRS 8198, Université des Sciences et Technologies de Lille - Lille 1, F-59655 Villeneuve d'Ascq cedex France.
Benjamin
B
Brachi
Laboratoire Génétique et Evolution des Populations Végétales, UMR CNRS 8198, Université des Sciences et Technologies de Lille - Lille 1, F-59655 Villeneuve d'Ascq cedex France.
Nathalie
N
Faure
Department of Ecology and Evolution, University of Chicago, 1101 E. 57 Street, Chicago, IL 60637, USA.
Joy
J
Bergelson
Laboratoire Génétique et Evolution des Populations Végétales, UMR CNRS 8198, Université des Sciences et Technologies de Lille - Lille 1, F-59655 Villeneuve d'Ascq cedex France.
Joël
J
Cuguen
Laboratoire Génétique et Evolution des Populations Végétales, UMR CNRS 8198, Université des Sciences et Technologies de Lille - Lille 1, F-59655 Villeneuve d'Ascq cedex France.
Fabrice
F
Roux
Arabidopsis thaliana; QTL; association mapping; common garden; phenology; phenotypic plasticity