Genome-wide association study unravels the genetic control of the apple volatilome and its interplay with fruit texture.

Brian Farneti,Mario Di Guardo,Fabrizio Costa,Franco Biasioli,Riccardo Velasco,Iuliia Khomenko,Luca Cappellin

doi:10.1093/jxb/erx018

Abstract

Fruit quality represents a fundamental factor guiding consumers' preferences. Among apple quality traits, volatile organic compounds and texture features play a major role. Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS), coupled with an artificial chewing device, was used to profile the entire apple volatilome of 162 apple accessions, while the fruit texture was dissected with a TAXT-AED texture analyzer. The array of volatile compounds was classed into seven major groups and used in a genome-wide association analysis carried out with 9142 single nucleotide polymorphisms (SNPs). Marker-trait associations were identified on seven chromosomes co-locating with important candidate genes for aroma, such as MdAAT1 and MdIGS. The integration of volatilome and fruit texture data conducted with a multiple factor analysis unraveled contrasting behavior, underlying opposite regulation of the two fruit quality aspects. The association analysis using the first two principal components identified two QTLs located on chromosomes 10 and 2, respectively. The distinction of the apple accessions on the basis of the allelic configuration of two functional markers, MdPG1 and MdACO1, shed light on the type of interplay existing between fruit texture and the production of volatile organic compounds.

Highlights

Fruits are important components of the human diet, supplying important elements such as sugars, organic acids, vitamins and fiber
It is known that volatile organic compounds (VOCs) can be distinguished in two categories (Yahia, 1994): those produced by whole fruit and those synthesized during chewing
The PTR-ToF-MS setting employed in this investigation enabled a full scan of the entire volatilome in 1 s, allowing real-time monitoring for most VOCs emitted by the fruit during chewing

Summary

Introduction

Fruits are important components of the human diet, supplying important elements such as sugars, organic acids, vitamins and fiber. The distinction of the apple accessions on the basis of the allelic configuration of two functional markers, MdPG1 and MdACO1, shed light on the type of interplay existing between fruit texture and the production of volatile organic compounds.

Results

Conclusion