Mapping QTLs for phytochemical compounds and fruit quality in peach

Genetic control and location of QTLs associated with phytochemical compounds and fruit quality in peach [Prunus persica (L.) Batsch] were evaluated using an F2 mapping population (ZC2) derived from cross between ‘Zin Dai’ × ‘Crimson Lady’. Antioxidant capacity, accumulation of phenolic compounds (total phenolics, flavonoids, and anthocyanins), and fruit quality traits (fruit diameter, fruit weight, fruit firmness, soluble solids concentration, titratable acidity, and ripening index) were evaluated for 2 years (2013–2014). Fourteen QTLs for phytochemical and fruit quality traits were identified in 5 LGs, with two QTL clusters (qPC.ZC_5.1_2014 and qPC.ZC_7.1) observed on LGs 5 and 7. The QTL cluster qPC.ZC_5.1_2014 was associated with antioxidant capacity, flavonoids, anthocyanin content, and SSC, while qPC.ZC_7.1 exhibited association only with flavonoids and fruit ripening index. QTL clusters associated with different fruit quality traits were observed on LGs 1 and 6. Candidate gene analyses of the QTL cluster on LG5 (qPC.ZC_5.1_2014) revealed 14 candidate genes in peach with functional annotation related to biosynthesis pathway of phytochemical compounds.