Résumé
Genome-wide association studies have proven their efficiency to decipher the geneticdeterminism of traits of agronomic interest in several plant species. In order to perform suchstudies in grapevine, we first designed an association panel of 279 V. vinifera cultivars from theFrench National Grapevine Germplasm Collection (Domaine de Vassal, INRA, France). It iscomposed of three subgroups of 93 cultivars representing the three main genetic pools, whichdiffer in use and geographical origin: wine West, wine East, table East. This panel exhibited agood genetic and phenotypic representativeness of the whole collection. Linkage disequilibriumextent was quite small, 43 Kb for a corrected r2 predicted value of 0.2, emphasizing the need forseveral dozen thousands markers to achieve powerful genome wide association studies. Thesecond step consisted in dense genotyping of this panel using a 18K SNP Infinium chip andgenotyping by sequencing (GBS). While the first method provided useful genotypes at 12K SNPs,about 100K SNPs are expected using GBS with ApeKI. Data processing is in progress and thisresource will be made available to the scientific community. The third step consists inphenotyping this panel for traits of interest. Vines were planted in a randomized block design atLe Chapitre Research Vineyard (Montpellier SupAgro, France). Traits related to yield (cluster andberry weights) and phenology (maturity date) were measured in three years within the DLVitisprogram. Then within the Innovine program, grass was used as a cover crop between rows in thewhole trial and part of the design was irrigated to obtain two levels of water availability. Inaddition to yield and phenology traits, berry composition (sugars, acids, anthocyanins, tannins andaromas), pruning weight and adaptation to drought (delta C13) have been measured during twogrowing seasons under both water availability conditions. This association panel, together withthe accumulated data, represent highly valuable resources for genetic studies in grapevine. We arecalling for an international collaborative effort to use such a panel in field and greenhouse trials toaddress questions on adaptation to changing environments.