Flowering time response to temperature in sweet cherry across Europe: multi-cultivar and multi-environment analysis

Résumé

In temperate fruit trees, most key phenological stages are highly dependent on environmental conditions. In particular, correct timing for dormancy and flowering is essential to ensure good fruit production and quality. Asa result, in a swiftly-changing environment, temperate fruit crop adaptation in many areas will be at risk in the coming decades. Global changes in environmental conditions include warmer winters and higher risks of frosts in the early spring, and may lead to a wide range of problems, in relation to flower and fruit set, cross-pollination,formation of double fruits, sun-scald, or novel host-pest interactions.In this context, one of the challenges will be to breed fruit trees adapted to future climatic conditions. Predictive models for flowering phenology based on genetic and phenology data will represent a valuable tool to assist in the process. In order to support the development of these models, we present an analysis of a wide dataset of flowering dates for sweet cherry cultivars, under different climatic conditions in Europe. These phenology data were provided through a French national network of experimentation (coordinated by CTIFL) and a European COST Action on cherries led by INRA-Bordeaux. Based on statistical analyses and hierarchical clustering, results revealed common and distinct patterns in the response to temperature for the different groups of cultivars. These information will be useful to better understand the main trends in flowering behaviour under different temperature conditions. Furthermore, such approaches will be applicable to many other important phenological traits, such as maturity or fruit set.