title: QTL validation and stability for volatile organic compounds (VOCs) in apple.
abstract: The aroma trait in apple is a key factor for fruit quality strongly affecting the consumer appreciation, and its detection and analysis is often an extremely laborious and time consuming procedure. Molecular markers associated to this trait can to date represent a valuable selection tool to overcome these limitations. QTL mapping is the first step in the process of targeting valuable molecular markers to be employed in marker-assisted breeding programmes (MAB). However, a validation step is usually required before a newly identified molecular marker can be implemented in marker-assisted selection. In this work the position of a set of QTLs associated to volatile organic compounds (VOCs) was confirmed and validated in three different environments in Switzerland, namely Wädenswil, Conthey and Cadenazzo, where the progeny 'Fiesta×Discovery' was replicated. For both QTL identification and validation, the phenotypic data were represented by VOCs produced by mature apple fruit and assessed with a Proton Transfer Reaction-Mass Spectrometer (PTR-MS) instrument. The QTL-VOC combined analysis performed among these three locations validated the presence of important QTLs in three specific genomic regions, two located in the linkage group 2 and one in linkage group 15, respectively, for compounds related to esters (m/z 43, 61 and 131) and to the hormone ethylene (m/z 28). The QTL set presented here confirmed that in apple some compounds are highly genetically regulated and stable across environments.
authors.affiliation: Research and Innovation Centre, Foundation Edmund Mach, Via Mach 1, San Michele all'Adige (TN), Italy. fabrizio.costa@fmach.it
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Costa
authors.forename: Luca
authors.initials: L
authors.lastname: Cappellin
authors.forename: Elena
authors.initials: E
authors.lastname: Zini
authors.forename: Andrea
authors.initials: A
authors.lastname: Patocchi
authors.forename: Markus
authors.initials: M
authors.lastname: Kellerhals
authors.forename: Matteo
authors.initials: M
authors.lastname: Komjanc
authors.forename: Cesare
authors.initials: C
authors.lastname: Gessler
authors.forename: Franco
authors.initials: F
authors.lastname: Biasioli
mesh_terms: D002874:Chromosome Mapping; D004777:Environment; D005030:Ethylenes / Q000378:metabolism*; D008040:Genetic Linkage; D027845:Malus / Q000235:genetics*; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism*; D040641:Quantitative Trait Loci / Q000235:genetics*; D055549:Volatile Organic Compounds / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; D055549:Volatile Organic Compounds; C036216:ethylene
keywords: Apple fruit quality; Aroma production; QTL mapping; QTL stability; VOCs