Genotypic and environmental effects on flavor attributes of ‘Albion’ and ‘Juliette’ strawberry fruits

• Strawberry volatiles were analyzed by headspace GC × GC–ToFMS.
• A control study monitored environmental conditions over a growing season.
• Genotypic effect was important for pH, titratable acidity and sugar:acid ratio.
• Environmental effects were most important for total soluble solids.
• Genotypic variation and G × E interactions were predominant for volatiles.

This work is aimed at investigating the genotypic and environmental effects on flavor attributes of two strawberry varieties, in particular, the Australian variety Juliette and the Californian variety Albion, when cultivated in the open field. Flavor quality parameters (i.e. pH, titratable acidity, total soluble solids content and sugar/acid ratio) and volatile compositions of these two genotypes were evaluated over ten harvest dates in one growing season. Correlations have been established between these flavor attributes with variations in air and soil temperatures, photosynthetically active radiation, relative humidity, soil moisture, and rainfall, during the growing season. While genotype was the major source of phenotypic variation for pH, titratable acidity and sugar/acid ratio, the total soluble solids content was more dependent on environmental conditions during production than on genotype. Fluctuations in soil and air temperatures, in particular, were found to significantly influence the total soluble solids content of strawberries. Furthermore, the effect of genotype was, for many volatile compounds, stronger than that of the environment. The genotype-by-environment interactions were highly significant for the four quality parameters, as well as for a majority of the volatile compounds. A set of environmental conditions have also been identified, which may be conducive for the production of highly flavorsome strawberries.