Rootstock-scion interaction:3. Effect on the composition of Cabernet Sauvignon wine

Abstract The interaction among rootstock, scion and environment may induce different responses to the grapevine physiology and consequently to the grape and wine composition. The vineyards of Serra Gaúcha, Brazil, are established in soils that may have different physicochemical attributes. Furthermore, the grapevines are grafted on a wide diversity of rootstocks. Therefore, this study aimed to determine their effect on the wine composition of the Cabernet Sauvignon (CS) grafted on Rupestris du Lot, 101-14 Mgt, 3309 C, 420A Mgt, 5BB K, 161-49 C, SO4, Solferino, 1103 P, 99 R, 110 R, Gravesac, Fercal, Dogridge and Isabel, featuring some genetic diversity altogether. The experimental design was in randomized blocks, with 15 treatments, three replicates and 10 vines per plot. The grapes were harvested at maturity for three years, and then wines were made in glass recipients of 20 L. When alcoholic and malolactic fermentations were over, the wine analyses were performed on twenty-five variables related to alcohol, acidity, dry extract, polyphenols and volatile compounds. The main results show that all variables were affected year by year, some of them by the rootstock and a few by the interaction between rootstock and year. The rootstock effect was observed mainly on variables related to alcohol, acidity and ashes. Results show that the CS/101-14 Mgt wine had higher alcohol content than CS/Dogridge and CS/Isabel wines, which was probably due to the 101-14 Mgt rootstock favoring an early grape ripening. However, higher pH values were observed in the CS/Rupestris du Lot, CS/5BB K and CS/Gravesac than CS/420A Mgt, CS/110 R and CS/Isabel wines. These results show that there is a diversity of rootstocks that can be used by the growers due to the Cabernet Sauvignon wine composition similarities.摘要 砧木、接穗与环境之间的互作可对葡萄生理产生不同调控效应，进而影响葡萄与葡萄酒的组分构成。巴西塞拉高查（Serra Gaúcha）产区的葡萄园所依托的土壤理化属性存在差异，且当地种植的葡萄均嫁接于种类繁多的砧木之上。为此，本研究旨在探究不同砧木对赤霞珠（Cabernet Sauvignon，CS）葡萄酒组分的影响，实验涉及的砧木包括Rupestris du Lot、101-14 Mgt、3309 C、420A Mgt、5BB K、161-49 C、SO4、Solferino、1103 P、99 R、110 R、Gravesac、Fercal、Dogridge以及Isabel，整体具备丰富的遗传多样性。本实验采用随机区组设计，共设置15个处理组，每组设置3次重复，每小区种植10株葡萄树。研究连续三年于葡萄成熟阶段进行采收，随后在20L玻璃容器中完成酿酒工序。待酒精发酵与苹果酸-乳酸发酵结束后，针对葡萄酒的25项指标开展分析，涵盖酒精度、酸度、干浸出物、多酚类物质以及挥发性化合物等维度。核心研究结果显示，所有检测指标均受年份因素影响，部分指标受砧木因素调控，少数指标同时受砧木与年份的交互作用影响。砧木效应主要体现在与酒精度、酸度及灰分相关的指标上。其中，CS/101-14 Mgt组合酿制的葡萄酒酒精度显著高于CS/Dogridge与CS/Isabel组合，推测该现象源于101-14 Mgt砧木可促进葡萄提早成熟。而CS/Rupestris du Lot、CS/5BB K与CS/Gravesac组合酿制的葡萄酒pH值则显著高于CS/420A Mgt、CS/110 R与CS/Isabel组合。上述结果表明，鉴于不同砧木酿制的赤霞珠葡萄酒组分存在共性，种植者可选用多样化的砧木进行葡萄栽培。