Genetic analyses of chilling requirements and flowering date in sweet cherry, two key traits for breeding programs
In boreal and temperate regions, the transition from active growth to a dormant phase is a necessary step for winter survival of woody plants. Winter dormancy can be separated into two main phases: endodormancy defined as the period during which the plant does not grow, followed by ecodormancy corresponding to the period during which bud cells are able to grow if temperatures are warm enough. Climate warming can thus delay endodormancy release while it accelerates bud growth. Therefore, depending on the balance between these two antagonistic effects, bud break can be either advanced, delayed, or even compromised. The objective of this work was to decipher the genetic control of dormancy and flowering in sweet cherry. Quantitative trait loci (QTLs) associated with temperature requirements were identified in an intraspecific sweet cherry F1 progeny following the evaluation of this trait during three years. QTLs associated with flowering date were identified in the same progeny and in a second one based on five and six years of evaluation, respectively. The results suggest that dormancy and flowering date in sweet cherry are controlled by complex mechanisms as already reported in other perennials. They provide the first basis for the identification of genes involved in chilling requirements and flowering date in sweet cherry that could be used to create new cultivars adapted to future climatic conditions.
Dirlewanger, E., Campoy, J.A., Wenden, B., Castède, S., Le Dantec, L., Barreneche, T. and Quero-García, J. 2017. Genetic analyses of chilling requirements and flowering date in sweet cherry, two key traits for breeding programs. Acta Hort. (ISHS) 1172:299-306
candidate genes, climate change, phenology, Prunus avium, QTLs