Allelic variation at a terpene synthase locus shapes wine monoterpene composition and aroma

Abstract

The genetic basis of wine monoterpene variation and its sensory consequences remain poorly understood. We investigated how allelic variation at a chromosome 10 linalool QTL harboring a terpene synthase cluster, including VviTPS54, influences wine aroma in a Riesling x Cabernet Sauvignon mapping population. Twenty-six wines from progeny selected for contrasting genotypes were subjected to HS-SPME-GC-MS profiling and descriptive sensory analysis. Genotypes carrying the high-linalool Riesling allele produced substantially elevated monoterpene levels dominated by (3S)-linalool. Berry and wine monoterpene profiles were significantly correlated, and berry monoterpene glycosides showed broad correlations with wine monoterpenes. High-monoterpene genotypes were more closely associated with Floral, Tropical Fruit, and Apricot/Peach attributes, though perception was modulated by matrix effects from berry pigmentation. These results demonstrate that allelic variation at a terpene synthase locus drives coordinated changes in wine monoterpene composition and linked sensory attributes, while underscoring the complexity of translating genetic variation into sensory outcomes.