Association mapping reveals gene action and interactions in the determination of flowering time in barley.
The interaction between members of a gene network has an important impact on the variation of quantitative traits, and can influence the outcome of phenotype/genotype association studies. Three genes (Ppd-H1, HvCO1, HvFT1) known to play an essential role in the regulation of flowering time under long days in barley were subjected to an analysis of nucleotide diversity in a collection of 220 spring barley accessions. The coding region of Ppd-H1 was highly diverse, while both HvCO1 and HvFT1 showed a rather limited level of diversity. Within all three genes, the extent of linkage disequilibrium was variable, but on average only moderate. Ppd-H1 is strongly associated with flowering time across four environments, showing a difference of five to ten days between the most extreme haplotypes. The association between flowering time and the variation at HvFT1 and HvCO1 was strongly dependent on the haplotype present at Ppd-H1. The interaction between HvCO1 and Ppd-H1 was statistically significant, but this association disappeared when the analysis was corrected for the geographical origin of the accessions. No association existed between flowering time and allelic variation at HvFT1. In contrast to Ppd-H1, functional variation at both HvCO1 and HvFT1 is limited in cultivated barley.
Stracke
Silke
S
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Gatersleben, Germany. sstrack@gwdg.de
Haseneyer
Grit
G
Veyrieras
Jean-Baptiste
JB
Geiger
Hartwig H
HH
Sauer
Sascha
S
Graner
Andreas
A
Piepho
Hans-Peter
HP
D002874:Chromosome Mapping; D035264:Flowers / Q000235:genetics / Q000254:growth & development; D006239:Haplotypes; D001467:Hordeum / Q000235:genetics* / Q000254:growth & development; D015810:Linkage Disequilibrium; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D011157:Population Dynamics; D040641:Quantitative Trait Loci
D010940:Plant Proteins