## 1 Introduction  
Wine has been of particular interest in the field of food sciences due to its unique sensory attributes and health properties [1, 2]. Wine aroma is one of the most important aspects that directly affect the overall quality of wine [3, 4]. Volatile compounds in wine are mainly derived from three origins: grape berry, fermentation, and aging. Volatile compounds in grapes can be extracted during fermentation process into wine and these volatiles mainly determine the varietal scents of wine [3, 5]. Additionally, fermentative aroma of wine, such as higher alcohols and esters, results generally from volatiles generated during the wine fermentation process [6, 7]. The wine aging process can further yield volatile compounds that possess aging characteristics, which can further wine complexity [8, 9]. There are several volatile compounds derived from grape secondary metabolism, including terpen, C\({}_{13}\)-norisoprenoids, methoxypryrazines, C\({}_{6}\) compounds, and volatile phenols [5, 10]. These compounds are responsible for the varietal aroma of wines. They are already present in the grapes in free or bound forms, and come into wine through fermentation unaltered or with only minor modifications [5]. Their content in grape is influenced by some genetic factors (variety and clone) and environmental and viticulture conditions (temperature, light exposure, irrigation and nitrogen availability), finally affecting the aroma quality of wine [11]. The typical aromas of certain varietal wines have been associated with some potent volatile compounds. For example, methoxypyrazines such as 3-isobutyl-2-methoxypyrazine (IBMP) and 3-isopropyl-2-methoxypyrazine (IPMP) are responsible for 'green bell pepper' aroma in Cabernet Sauvignon, Carmenere, and Sauvignon Blanc wine [12; 13], and monoterepenes such as linalool and geraniol greatly contribute to the 'floral' character of most Muscat varieties [14]. In addition, several studies have shown that different clones of the same grape variety also exhibit significant differences in their productive characteristics and ability to produce wines with different organoleptic characteristics [15; 16; 17]. It has been reported that different clones have the ability to produce wines with distinct color [18], phenolic content [19; 20; 21], aromatic profile [22; 23; 24; 25], and elemental profile [18; 26] in several grape varieties. Some research on the differences in volatile composition in grapes and wines from clones of different varieties has been conducted. It has been found that different Sauvignon Blanc clones display varied concentrations of thiol precursors in grape juices and free thiols in wines [27; 28]. [PERSON] et al. (2007) also found that clone was an important factor affecting the methoxypyrazine content in Carmenere wine [12]. [PERSON] observed variation in free and bound 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and vitispirane concentrations among eight Riesling clones [25]. Therefore, the clonal selection is very important for obtaining the specific characteristics of the grapes and wines. Oak barrel aging is a common process for red wine maturation since this process can significantly enhance the complexity of wine through incorporating wine with important aging featured volatiles [29; 30]. For example, oak barrel odorants, such as lactones and volatile phenols, can be extracted from the oak barrel to the wine during the aging process, which resulting in the aging attributes of red wine [29]. Meanwhile, oxidation, condensation, hydrolysis, and esterification also happen during the wine aging process, potentially resulting in the formation of many new volatile compounds, and these compounds can improve the aromatic complexity of wine [31]. It is known that oak barrel type and toasting level are two important factors that impact wine aging performance [32; 33]. It has been reported that a short aging process can release the limited volatiles from the oak barrel to the wine matrix, which does not effectively improve wine aging features.