Modifications of Vitis vinifera L. cv. Petit Verdot grape flavonoids as affected by the different rootstocks in eastern China

Rootstocks are widely used in viticulture because of their strong ability to resist biotic and abiotic stress. In two-successive years (2016−2017), the effects of five rootstocks (101-14MGt, 1103P, Beta, 5BB, and SO4) on the berry flavonoid profiles of Petit Verdot were evaluated by HPLC-MS. The results showed that there was limited influence of rootstocks affecting the technological ripening of Petit Verdot. With respect to flavonoid compounds, 1103P and Beta tended to increase the concentrations of anthocyanin in grape skins in the two seasons. 101-14MGt and 1103P enhanced the flavonol concentrations, whereas Beta showed a detrimental effect on the biosynthesis of flavonols except for syringetin. Additionally, despite the season factor dominating the effect on flavan-3-ols, 101-14MGt tended to show a slight increase in flavan-3-ol concentrations in skins and seeds. In conclusion, based on the evaluation of physicochemical indicators and flavonoid compounds of mature berries, the current study provided data for grafting of Petit Verdot on various rootstocks in eastern China.