Identification of Quantitative Trait Loci (QTLs) Controlling Bud Dormancy-Associated Traits in Japanese Apricot (Prunus mume)

Bud dormancy represents a pivotal physiological process in woody perennials, enabling them to acclimate to seasonal environmental fluctuations. The satisfaction of genotype-specific chilling requirements (CR) and heat requirements (HR) through exposure to distinct chilling and warm temperatures is imperative for dormancy release and subsequent growth resumption. Despite this, the genetic mechanisms governing bud dormancy and bud break in Prunus mume remain incompletely elucidated. In this study, using an F1 segregating population resulting from the cross between the Japanese cultivar 'Nanko' (CR:600-1100 CH) and the low-chill variety 'SC' (CR: 0-400 CH) that adapted to subtropical conditions, we identified a major QTL for CR, HR, and bud break on chromosome 4 (LG4 QTL) within the 'Nanko' genome and a sub-major QTL for CR and HR on chromosome 7 (LG7 QTL) within SC genome .