## 3 Results
### Effects of Rostotsots on Merlot Berry and Wine Volatile Composition  
Table 3 lists the concentrations of the main aroma compounds in the Merlot scion-rootstocks grapes and wines. C6 volatile compounds have been reported as characteristic compounds for non-muscat grape cultivars mainly composed of two aldehydes, five alcohols, three esters, and one acid [25]. As the most abundant volatile compounds in grapes, hexanal and _(E)_-2-hexenal are two dominant C6 aldehydes from linoleic/linolenic acid in the LOX pathway. They were found to be greenish, with a fruity flavor, and to significantly influence the aromatic feature of the grapes [26; 27]. Regarding the C6 aldehydes, hexanal and _(E)_-2-hexenal were found in MT and MT-5 BB grapes but appeared in all Merlot wines. Wine from own-rooted Merlot was shown to have the highest hexanal and _(E)_-2-hexenal levels. With three Merlot scion-rootstocks, MT-1103P presented a higher level than MT-5 BB and MT-SO4. Concerning C6 alcohols, MT-1103P and MT-SO4 grapes had only hexanol, while MT and MT-5 BB grapes had hexanol, _(Z)_/_(E)_-3-hexenol, and _(E)_-2-hexenol. These three C6 alcohol profiles were all found in wines from MT, MT-5 BB, MT-1103P, and MT-SO4. Additionally, these Merlot scion-rootstock wines contained higher contents of _(E)_-2-hexenol than _(Z)_/_(E)_-3-hexenol. Similar observations were made in other grape cultivars [27; 28; 29]. Meanwhile, MT-5 BB and MT-SO4 had a higher _(E)_-2-hexenol level than MT whereas MT-1103P showed the lowest level. This differed from the results of a study that showed wine from own-rooted Merlot with the lowest content of _(E)_-3-hexenol and the highest content of hexanol and _(Z)_-3-hexenol [18]. Rootstocks gave the Merlot grapes a markedly higher hexanol than own-rooted Merlot, which was also manifested in wines. C6 esters, as important volatiles, have been depicted as fruity, floral, and sweet flavors in fruits [30; 31]. Isobutyl acetate, the only C6 ester, was found in MT-1103P and MT-SO4 scion-rootstocks grapes. Hexanoic acid was found in Merlot scion-rootstock grapes and wines, the same as in a past study [27]. Wines from MT-5 BB and MT-SO4 had higher hexanoic acid levels than MT and MT-1103P when the C6 acid was present only in MT and MT-5 BB grapes. At the same time, MT-1103P and MT-SO4 grapes contained another C6 acid, named butanoic acid, and ethyl ester. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**Grapes**} \\ \cline{2-7}  & **MT** & **MT-5 BB** & **MT-1103P** & **MT-SO4** & **MN** & **MN-5 BB** & **MN-1103P** \\ \hline Total sugar & 196.77 \(\pm\) 0.42 b & 191.87 \(\pm\) 0.26 c & 206.40 \(\pm\) 0.64 b & 187.47 \(\pm\) 0.62 d & 204.27 \(\pm\) 0.53 A & 197.23 \(\pm\) 0.45 B & 193.10 \(\pm\) 0.43 C \\ Glucose & 96.40 \(\pm\) 0.78 a & 86.70 \(\pm\) 0.90 c & 93.17 \(\pm\) 0.54 b & 84.60 \(\pm\) 0.51 d & 93.06 \(\pm\) 0.48 A & 90.03 \(\pm\) 0.52 B & 87.43 \(\pm\) 0.52 C \\ Fructose & 98.57 \(\pm\) 1.09 c & 103.17 \(\pm\) 0.90 b & 111.50 \(\pm\) 0.78 a & 101.13 \(\pm\) 0.86 b & 108.83 \(\pm\) 0.59 A & 105.40 \(\pm\) 0.50 B & 102.83 \(\pm\) 0.52 C \\ Total soluble & 219.07 \(\pm\) 0.21 d & 229.37 \(\pm\) 0.53 b & 248.40 \(\pm\) 0.70 a & 225.20 \(\pm\) 0.99 c & 244.37 \(\pm\) 0.54 A & 236.50 \(\pm\) 0.64 B & 231.13 \(\pm\) 0.33 C \\ Titralable & 5.61 \(\pm\) 0.06 b & 6.53 \(\pm\) 0.08 a & 6.56 \(\pm\) 0.03 a & 6.58 \(\pm\) 0.02 a & 6.94 \(\pm\) 0.04 C & 7.85 \(\pm\) 0.05 A & 7.34 \(\pm\) 0.10 B \\ acidity & 39.04 & 35.13 & 37.86 & 34.22 & 35.21 & 30.13 & 31.49 \\ \hline \multicolumn{7}{c}{All parameters are listed with their standard deviations (n = 3). For each parameter, values with different letters are significantly different between the samples (\(p\leq\) 0.05).} \\ \end{tabular}
\end{table} 
Table 1: Effects of physicochemical parameters in Merlot and Marselan berries induced by the rootstocks (g/L).