Mapping the ‘Wild Strawberry’ Aroma in a Fragaria vesca NIL Collection

F. vesca is a simplified model for the study of the strawberry genetics. The availability of a quality reference genome and the recently developed near isogenic line (NIL) mapping collection are powerful tools for the study of any genetic trait. In this study we pursue the mapping of the wild strawberry-like aroma performing detailed profile of the volatile composition of F. vesca NIL collection. Fully ripe berries from 42 NILs were collected, gas chromatography-mass spectrometry (GC-MS) analyzed and total RNA extracted. In order to assess which regions of the genome could be responsible for the variations in volatile ratios, a QTL analysis was performed. We were able to map a total of 126 QTL from 81 different compounds including esters, aldehydes, alcohols, ketones, terpenoids and furans. The QTL mapping revealed 50 major stable QTL that accounted for a high proportion of the variability of 47 compounds, including 14 major QTL for 13 ‘key compounds’ responsible of strawberry aroma. The transcriptome of fully ripe fruits from selected NILs and the recurrent parental of the NIL collection F. vesca var. ‘Reine des Vallées’, were sequenced. Many QTL co-locate in few genetic regions according to clusters suggesting a control by a reduced number of loci. Two genetic regions that harbor interesting QTL involved with strawberry aroma perception have been selected to perform a whole transcriptomic study. The differential expression analysis of the red-ripe fruits allowed to highlight differentially expressed genes related to wild strawberry aroma variation.