# Rootstock Effect on Volatile Composition of Albarino Wines
## 3 Results and Discussion
### Wine Volatile Composition
With respect to volatile acids, five compounds were significantly affected by the rootstock (2+3 methylbutyric, hexanoic, decanoic and dodecanoic acids), with higher concentrations for wines from 110R in both vintages. The highest concentration of decanoic and hexanoic acids was also shown for 110R in the 2010 vintage. However, the higher contribution of ethyl esters to Albarino wine was shown when grapevines were grafted onto SO4 (58.7%). [PERSON] et al. [9] found higher levels of total fatty acids in Merlot wines from grapevines grafted onto SO4 than those from grapevines grafted onto Gravesac and 110R. The rootstock also affected, to a greater extend, the esters and acetates in the 2010 vintage (nine compounds) than in the 2009 vintage (five compounds). Only ethyl decanoate was not influenced by the rootstock in any of the vintages. The highest values of these compounds were shown for 110R, with the exception of ethyl lactate and isoamyl acetate in 2009, where the highest concentration was found for 420A and 41B respectively. In the 2010 vintage, ethyl octanoate, hexyl acetate and isoamyl acetate exhibited the highest values for 420A. Gravesac and 110R showed lower values of ethyl octanoate in Merlot wines [9]. Moreover, Merlot wines from SO4 had lower diethyl succinate and higher ethyl lactate content than those from grapevines grafted onto other rootstocks included in the study [9]. In the same way to our work, [PERSON] et al. [9] showed that the total ethyl ester content was higher in wines obtained from grapevines grafted onto Gravesac when compared to those obtained from SO4 grafted vines. The vintage affected all ethyl esters and acetates. Ethyl esters are responsible for the fruity aromas, which improve the wine quality [32]. From terpen and C\({}_{13}\)-norisoprenoids, four compounds were identified in Albarino wines. The rootstocks significantly affected to linalool, \(\alpha\)-terpineol and \(\beta\)-damacenone concentrations in 2009 and Ho-trienol in 2010. The highest values of C\({}_{13}\)-norisoprenoids were reached for 110R (2009) and 3309C (2010). The 3309 Couderc (3309C) plant vigor is low to moderate, and the growth speed is a little slow. However, the obtained products of plants grafted with this rootstock have recognized quality [19]. Vintage effect and interaction R\({}^{\prime}\)V were only significant for \(\beta\)-damascenone. Studies reported the impacts of different rootstocks on quality of wine grape berries, where the highest wine quality was produced by Chardonnay and Pinot noir vines grafted on 110 R, as compared to the other rootstocks [8]. Esters and terpen both contribute to the fruity and floral aromas. In addition, C\({}_{13}\)-norisoprenoids, also characterized by floral aromas, are important volatile compounds due their contribution to wine aroma, because they showed low olfactory thresholds [33]. A recent study on rootstock effects on Cabernet Sauvignon showed that SO4 induced a reduction in concentration of total esters, whilst 110R increased the concentration of C\({}_{13}\)-norisoprenoids at harvest [14]. In the same way, [PERSON] et al. [18] also reported that Summer Black grafted on SO4 caused a reduction in ethyl ester content, compared to own-rooted. In agreement with those results, Albarino wine from vines grafted in SO4 showed lower ethyl esters and terpen concentration, mainly in the 2010 vintage. In this sense, wines from vines grafted on SO4 may induce adverse effects, whereas 110R has a positive influence on Albarino wines. [PERSON] et al. [34] applied sensory analysis to determine the influence of rootstocks on Shiraz wine quality, showing that the highest quality scores were obtained by wines from vines grafted in110 Richter and the lowest by wines from own-roots. Principal components analysis (PCA) was performed on the different groups of volatile compounds, to visualize the differentiation of the wines on the bases of the different rootstocks and vintages (Figure 2).