S11 - Session O1 - Genotype-by-environment interactions in major agronomic traits in sweet cherry: flowering date and fruit quality

Authors: José Quero Garcia *, Camille Branchereau, Craig Hardner, Bénédicte Wenden, David Alletru, Julien Parmentier, Anton Ivancic, Daniela Giovannini, Federica Brandi, Gregorio Lopez-Ortega, Federico Garcia-Montiel, Elisabeth Dirlewanger

Flowering and fruit production in sweet cherry ( Prunus avium ) are strongly environment-dependent. Climate change, by inducing elevations of temperatures in winter and spring, can lead to strong yield and economic losses. With increased temperatures in winter, chilling requirements for dormancy release are not satisfied, which causes a delay in the release of dormancy and flowering disorders. On the other hand, a rise of the temperatures in spring induces earlier blooming dates and therefore a higher frost risk. Thus, increasing our knowledge about the genetic control of flowering and fruit-related traits in sweet cherry is a key step to obtain new varieties well adapted to changing environment and to ensure the production of cherry in the future. The genetic determinism of flowering date and main agronomic and fruit quality traits such as maturity date, productivity, fruit weight, firmness and sugar/acidity content were evaluated. QTL detections were conducted on a sweet cherry F1 population derived from the cross between cultivars 'Regina' and 'Lapins'. The population, composed of 122 individuals, was planted in five locations across four European countries (France, Italy, Slovenia and Spain), constituting a multi-environment trial (MET) usable for the study of the genotype-by-environment interactions (GxE). QTL detection for flowering date confirmed the presence of a major QTL on linkage group 4 (LG4), explaining up to 40% of the phenotypic variation. This QTL is highly significant in all environments but Murcia, the only location characterized by a mild winter. In Murcia, another region was identified at the end of LG1 and is the major one demonstrating the high effect of environmental conditions on the flowering process. Factor-analytical models were applied to the analysis of the MET and patterns of GxE were explored for all traits.