Targeted metabolomics approach for the characterization of wild Vitis genotypes

Wine is one of the most popular beverages in the world which is exclusively produced from Vitis vinifera varieties due to the superior quality of their grapes. However, today a large amount of fungicides and pesticides are used in viticulture in order to protect grapevine from their pathogens with a strong impact on environment and human health. For this reason, research has focused on the development of new interspecific hybrids using wild American genotypes in order to introgress their resistant traits to pests and diseases in V. vinifera cultivars. Despite this, little is known regarding the metabolic profile of wild genotypes. The aim of this work was to characterize the grape composition of two hybrids varieties (41B and K5BB) and five wild genotypes (V. andersonii, V. arizonica Texas, V. champinii, V. cinerea and V. californica) in six different vintages. Also V. vinifera cultivars (Pinot Noir and Cabernet Sauvignon) were taken into consideration as references. A targeted metabolomics strategy was used for the investigation of simple phenolic compounds, anthocyanins, proanthocyanidins and lipids. In particular, grape skins anthocyanins were analyzed using LC-DAD [1]. Three genotypes contained diglucosides for less than 5% of the total anthocyanins while four genotypes accounted for more than 40% of the total. LC-MS/MS methods were used for the study of phenolic compounds and lipids [2,3]. The results obtained showed that three wild genotypes contained higher average amount of total phenols and that the one out of seven non-V. vinifera genotypes contained a higher content of total lipids compared to V. vinifera cultivars. Analysis of proanthocyaninds by LC-MS showed that wild genotypes were mainly rich in oligomers and short-chain polymers [4]. Heatmap analysis was used to point out the differences in genotypes’ content for the different metabolites studied. This work demonstrates the existence of a significant genotypic diversity between the grape composition of V. vinifera and other species. The information gained could be very useful for the future grapevine breeding.