Metabolomic analyses in sweet cherry

In sweet cherry (Prunus avium L.) organoleptic quality is part of the main fruit traits for breeders and consumers. Two F1 progenies, ‘Regina’ × ‘Lapins’ (R×L) and ‘Fercer’ × ‘Burlat’ (F×B), were used to analyse the genetic determinism of traits related to organoleptic quality: titratable acidity, pH and refractometric index were analysed on R×L during three years: 2006, 2008 and 2013 on 83, 106 and 114 individuals, respectively. Major soluble carbohydrates (glucose, fructose, sucrose and sorbitol) and major organic acids (citrate and malate) were analysed in 2012 on R×L and F×B on 106 and 111 individuals, respectively. Metabolite quantification was performed using robotised microplate-based assays in three replicates per tree, consisting of a mixture of fruit skin and pulp obtained by pooling five fruits . Genotyping was performed with the RosBREED’s cherry 6K SNP array v1 and linkage maps for the two progenies were constructed with JoinMap 4.0 software. QTL mapping was carried out using MultiQTL V2.6 software.
Titratable acidity and pH were negatively correlated, and major QTLs for both traits were detected on LG6. For sugars and organic acids a QTL with major effect was only detected for malic acid on LG6, co-localizing with pH and titratable acidity QTLs. QTLs for malic acid were also detected on LG1 and LG5, but having lower effect. QTLs for sorbitol were detected on LG2 and LG3. QTLs with very low effect were detected for glucose and sucrose on LG4 and LG3, respectively.