Wine colour adsorption phenotype: an inheritable quantitative trait loci of yeasts

Aims: In this work, a population of 88 descendants derived from three wine strains of Saccharomyces cerevisiae was tested for the enological trait 'wine colour adsorption' (WCA) to evaluate its inheritability. Methods and Results: The WCA phenotype was tested on plate agar medium specifically formulated for the purpose. After 10 days of anaerobic incubation at 28 C, a computer-assisted assessment of WCA aptitude of the yeasts was carried out. The biomass colour - ranging from white to dark brown - reflects the adsorption of grape pigments: white and dark brown biomass colour corresponds to low and high adsorption, respectively. In order to confirm biomass colour results, microvinification trials using red must were performed, and the obtained wines were analysed. Conclusions: The analysis of the progeny demonstrated that the enological trait WCA is inheritable and polygenic. Significance and Impact of the Study: A way to describe the polygenic effect of the WCA trait has been found, also showing that this trait is inheritable. The impact of the work revolves more around the large-scale screening method, which could then assist in breeding wine yeast, and can also be used as a scientific tool to investigate WCA trait.