Flavour improvement in early generations of fresh market tomatoes (Solanum lycopersicum): I. Identification of QTL for sensory attributes, physicochemical measurements and volatile compounds

Abstract

Human sensory analysis is the most appropriate method for assessing the flavour of fresh market tomatoes, but it is very labour and time consuming. Therefore, sensory attributes are often neglected in early generations of breeding programmes and genetic studies, although there is a demand for tomatoes with improved flavour. In this study, the recently developed Breeders' Sensory Test was applied to an F2 mapping population derived from two parents with superior flavour. Sensory attributes, physicochemical measurements, volatiles and fruit weight were assessed in organic low-input and hydroponic cultivation. A linkage map spanning 1070 cM was developed. In total, 71 quantitative trait loci (QTL) were detected for the means of both cultivation systems, 61 for organic and 46 for hydroponic cultivation. A proportion of 27% of the loci were co-localized between both cultivation systems. Nine distinct QTL clusters for flavour-related traits were identified, including a large cluster on chromosome 6 comprising five sensory and nine volatile QTL. The sensory QTL on chromosomes 2, 5, 6, 10 and 11, partly within clusters, are recommended for marker-assisted selection.