HvFT1 (VrnH3) drives latitudinal adaptation in Spanish barleys

In barley, three genes are responsible for thevernalization requirement: VrnH1, VrnH2 and VrnH3. Thewinter growth habit of barley requires the presence of arecessive VrnH1 allele, together with an active VrnH2allele. The candidate for VrnH3 (HvFT1) has been recentlyidentiWed, with evidences pointing at a central role in theintegration of the vernalization and photoperiod pathways.Functional polymorphisms have been proposed, but experimentalevidence of their role on agronomic performanceand adaptation is needed. We examined allelic variation atthe promoter and intron 1 of the HvFT1 gene in a landracecollection of barley, Wnding a high diversity level, with itsgeographic distribution correlated with latitude. Focusingon genotypes with winter alleles in VrnH1 and VrnH2, anassociation analysis of the four main HvFT1 haplotypesfound in the landrace collection detected diVerences in timeto Xowering. Landraces with the intron 1 TC allele, prevalentin the south, Xowered 6-7 days earlier than those withthe AG allele, under natural conditions. These results werevalidated in an independent F2 population. In both data sets,the eVect found was similar, but in opposite direction tothat described in literature. The polymorphism reported atintron 1 contributes to variation in Xowering time underWeld conditions. We have found that polymorphisms at thepromoter also contribute to the eVect of the gene on Xoweringtime under Weld and controlled conditions. The varietyof HvFT1 alleles described constitutes an allelic series thatmay have been a factor in agro-ecological adaptation ofbarley. © Springer-Verlag 2011.