Domestication effects in European breeding history of strawberry demonstrated by aroma compound pattern

Abstract

Domestication of plants results in wanted improvements but also in negative side-effects effects depending on the genetic constitution of the material, in particular, after intense breeding. Negative effects, for example, losses in aroma and resistances are obvious for horticulturists as well as for consumers. Molecular studies demonstrated the loss of allelic diversity (Gil-Ariza et al., 2009; Horvath et al., 2011). In this study, we investigated 50 old and modern European strawberry cultivars released between 1849 and 2016. All available fruit from ten plants per cultivar were harvested and analyzed as a batch by immersion stir bar sorptive extraction-gas chromatography-quadrupole mass spectrometry (lmm-SBSE-GC-qMS). The sum of all detected 82 volatile organic compounds (VOCs) including 18 character impact compounds were evaluated with respect to the breeding history. Overall, old cultivars as a group showed a much higher diversity in aroma patterns in quality and in quantity of the sum and the quantity of single VOCs in comparison to modern cultivars. A high number of VOCs showed a much higher range of values (relative concentrations) in old cultivars. Some VOCs are lacking in modern cultivars, for example, methyl anthranilate is present in nearly the half of the cultivars released before 1952 whereas no modern cultivar showed detectable amounts of this important ester characterized by a flowery, wood-strawberry-like odour. On the other hand, a third of the old cultivars did not show the aroma-active compound ydodecalactone in contrast to the modern cultivars with 100% detectability. Linalool as a key compound with flowery and citrus-like odor impression varied in cultivars released before 1960 from zero to a value of 106 relative concentration. In modern cultivars, it was detectable throughout the collection with values of 3 to 67 relative concentrations. The data showed changes in the profile of aroma in the process of domestication. The complaints about the flavor and the low sensorial quality of modern cultivars are reflected to a certain extend in the aroma patterns.