Grapevine Rootstock Genotype Influences Nitrogen Levels, Must and Wine Composition and Sensory Characteristics of Assyrtiko (<em>Vitis vinifera</em> L.)

This study examined the impact of five grapevine rootstocks (110 R, 140 Ru, 3309 C, 41 B, and FERCAL) on must composition, nitrogen status, and sensory attributes of Vitis vinifera L. cv. Assyrtiko wines. Vines were grown under uniform vineyard conditions, and microvinifications were conducted consistently across treatments. Rootstock genotype significantly influenced Baumé, density, titratable acidity, pH, and yeast-assimilable nitrogen (YAN). Musts from R110 contained the highest YAN (227.2 mg/L) and intermediate Baumé (12.5°), whereas 140 Ru exhibited the lowest YAN (133.2 mg/L) and Baumé (11.7°). These differences were reflected in fermentation kinetics and final wine composition. Wines from R110 contained the highest tannin concentration (0.375 g/L), while FERCAL produced the highest ethanol content (13.1 % vol). Sensory evaluation revealed significant rootstock effects on colour intensity, aroma intensity, aroma complexity, balance, and overall quality, with R110 and 3309 C receiving the highest scores. The findings demonstrate that rootstock selection may affect the chemical and sensory profile of Assyrtiko wines, providing a practical tool for optimizing wine style and quality across diverse viticultural environments. Further research is needed to confirm these findings and explore extra parameters and novel rootstock-scion interactions.