Genetic dissection of aroma biosynthesis in melon and its relationship with climacteric ripening

Aroma is an essential trait in melon fruit quality, but its complexity and genetic basis are still poorly understood. The aim of this study was the identification of quantitative trait loci (QTLs) underlying volatile organic compounds (VOCs) biosynthesis in melon rind and flesh, using a Recombinant Inbred Line (RIL) population from the cross ‘Piel de Sapo’ (PS) × ‘Védrantais’ (VED), two commercial varieties segregating for ripening behavior. A total of 82 VOCs were detected by gas chromatography–mass spectrometry (GC–MS), and 166 QTLs were identified. The main QTL cluster was on chromosome 8, collocating with the previously described ripening-related QTL ETHQV8.1, with an important role in VOCs biosynthesis. QTL clusters involved in esters, lipid-derived volatiles and apocarotenoids were also identified, and candidate genes have been proposed for ethyl 3-(methylthio)propanoate and benzaldehyde biosynthesis. Our results provide genetic insights for deciphering fruit aroma in melon and offer new tools for flavor breeding.This work was supported by the Spanish Ministry of Economy and Competitiveness grants AGL2015–64625-C2–1-R and RTI2018-097665-B-C2, the Severo Ochoa Programme for Centres of Excellence in R&D 2016-2010 (SEV-2015-0533), the CERCA Programme/Generalitat de Catalunya and 2017 SGR 1319 grant from the Generalitat de Catalunya to JGM. The authors also wish to thank the support of the Secretaria d'Universitats i Recerca del Departament d'Empresa i Coneixement de la Generalitat de Catalunya for having funded the 2019 FI_B 00124 project, and the co-funding of the European Social Fund (ESF – “ESF is investing in your future”) from the European Union.Peer reviewe