Wine chemical profiling of genotypes obtained from crosses involving Croatian native grapevine germplasm

Abstract

One of the goals of the breeding program launched at the Faculty of Agriculture in Zagreb is to create new varieties resistant to fungal diseases suitable for growing in Croatian wine regions. Moreover, the newly created varieties should have acceptable chemical profiles that are comparable to traditional vinifera varieties. Selected genotypes included in this study were obtained by crossing ‘Grk’ x ‘Panonia’ (GRP genotypes) and ‘Dišeća ranina’ x ‘Panonia’ (DRP genotypes). After genotyping, 14 genotypes were confirmed to inherit resistant genes, and are now subjected to chemical profiling.

After harvesting at technological maturity, microvinification was carried out, and the resulting wines were subjected to physicochemical analyses and volatile profiling. Physicochemical analyses included basic chemical parameters of the wine, such as the alcohol content, extract, and total acidity, as well as individual acids present in the wine. The results revealed significant variability among genotypes, with several genotypes showing promising oenological characteristics. Wines produced from genotypes DRP-4, DRP-7 and GRP-17 showed significantly higher alcohol content and extract, while GRP-17 showed the lowest total acidity. This variability indicates that it would be possible to produce different wine styles in accordance with the basic chemical characteristics.

Analysis of volatile organic compounds confirmed the presence of esters, higher alcohols, and other aroma-active compounds in concentrations comparable to those found in vinifera wines, without the presence of undesirable ‘foxy’ aromas typical for earlier generations of resistant cultivars. Results also revealed high concentrations of esters, norisoprenoids and terpenes in comparison to wines made from at least one parent variety. The PCAanalysis further explained the variability. Among GRP genotypes, GRP-33 was singled out by its high presence of terpene compounds, while GRP-16 and GRP-36 grouped closely to Grk. Among DRP genotypes, genotype DRP-4 was singled out by high concentrations of terpenes, fatty acids, and volatile phenols. Other DRP genotypes were situated between parent genotypes, indicating similarity to both parents.

In conclusion, this study confirmed that the listed genotypes combine favourable physicochemical composition with desirable resistance to fungal diseases. This proves that resistance breeding does not necessarily compromise wine quality and that new grapevine varieties are suitable for wine production.

Acknowledgements

This research was funded by the Croatian Science Foundation, grant number IP-2022-10-9428 project “Application of metabolomics, high-throughput phenotyping and molecular markers in early selection for disease resistance in the development of new grape varieties—VitiResist”.