Effect of rain-shelter cultivation on the monoterpenes profile of Muscat Hamburg grapes and wines

Abstract Monoterpenes make important contributions to the aroma of grapes and wine. In this study, the monoterpene profiles and related gene expression patterns were investigated in vitis vinifera cv. Muscat Hamburg grapes grown under open-field and rain-shelter cultivation for two vintages. The results showed bound monoterpenes biosynthesis was repressed during the rainy season. There were no significant differences on the concentration of most of individual monoterpenes in grapes between rain-shelter and open-field cultivation in 2018. Compared with open-field cultivation, grapes under rain-shelter cultivation and the resulting wines had greater contents of monoterpenes in the rainy vintage (2019), in line with the higher expressions of most of the TPSs genes in rain-shelter cultivated grapes. Rain-shelter cultivation might improve tolerance to seasonal rain-induced stresses. The present study has revealed the influence of rain-shelter cultivation on monoterpene compounds in Muscat Hamburg grapes and wines thus providing a useful technique for improving the aroma quality of grapes and wines in the rainy season.