Analysis of aroma-related volatile compounds affected by ‘Ginsen Makuwa’ genomic regions introgressed in ‘Vedrantais’ melon background

Abstract

Volatile organic compounds (VOCs) have an important role in melon flavour, one of the most important traits influencing consumer’s preferences. The volatile profile of 25 introgression lines(ILs), developed from the Japanese cultivar ‘Ginsen makuwa’ (MAK) and the ‘Charentais’ cultivar ‘Vedrantais’ (VED), as donor and recurrent parent, respectively, was characterized in two environments. A total of 57 VOCs were identified using purge and trap extraction followed by chromatography-mass spectrometry. In addition, the IL population was genotyped with 2146 SNP distributed throughout the melon genome to tag Makuwa introgressions. The aromatic profiles of both parents (VED and MAK) and the hybrid revealed the genetic dominance of the MAK alleles against the VED alleles. MAK fruit displayed a significant decrease of most VOCs, mainly alkyl esters and apocarotenoid, compared to VED fruit, but had higher amounts of some specific aldehydes, esters, and phenolic compounds, such aseugenol. MAK introgressions affected the production of VOCs in ILs. Although the environmental effect was remarkable, the trend of certain ILs was similar in both environments. Interesting ILs were detected with specific VOCs affected by specific MAK introgressions and also some ILs showed changes in VOCs profiles due to pleiotropic effects of changes in color flesh and the ripening process. Joint analysis of VOCs profile and ILs GBS genotypes allowed the identification of candidate genes for volatile production, such as MELO3C024886 (4- coumarate:CoA ligase) involved in the eugenol pathway, CmCRTISO1 (MELO3C009571, carotenoid isomerase) related with the accumulation of carotenoids, precursors of the volatiles apocarotenoids, MELO3C006703 and MELO3C006545 (acyl-CoA ligases genes) involved in esters profile, and MELO3C030975 (aminotransferase) related with the aldehydes production. This study show how the use of genetic resources, such as those of the makuwa group, for breeding commercial melon can have an impact on the aromatic profiles.