Abstract

The effects of different rootstocks on the grape quality and volatile aromatic compounds of ‘Shine Muscat’ were investigated. The basic physicochemical parameters of berries from five scion–rootstock combinations (SM-Beta, SM-SO4, SM-5C, SM-Fercal, SM-YN2) and own-rooted ‘Shine Muscat’ grape were measured, and their volatile aromatic compounds were determined using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS). Our results showed that the SM-YN2 combination exhibited the highest berry weight, and increased by 28.13% compared with SM self-rooted seedling. In addition, the ‘5C’ and ‘YN2’ rootstocks could better maintain total soluble solids (TSS), titratable acidity (TA), TSS/TA and pH in the berries, whereas the ‘Beta’, ‘SO4’ and ‘Fercal’ rootstocks impaired TSS. Volatile profiling identified 841 volatile compounds classified into 15 categories, among which terpenoids constituted the predominant contributors to berry aroma. Furthermore, 22 characteristic aroma compounds were screened, and linalool presented the highest concentration among all terpenoids in ‘Shine Muscat’ fruit. Odor activity values (OAVs) and aroma proportion analyses further revealed that linalool is the key compound for the characteristic ‘muscat’ aroma of ‘Shine Muscat’. In addition, the SM-YN2 combination exhibited 31.96% and 4.61% higher concentration and proportion of linalool compared to own-rooted vines. Notably, with the exception of ‘YN2’, ‘Beta’, ‘SO4’, ‘5C’ and ’Fercal’ downregulated the expressions of one or more terpenoid synthesis-related genes. In conclusion, grafting onto rootstock could improve berry quality, particularly the ‘YN2’ rootstock, which yielded ‘Shine Muscat’ grapes with the highest overall quality. As a resource of the East Asian grape group, ‘YN2’ can be utilized as a rootstock in future production.

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