Impact of grapevine rootstock genotypes on nitrogen status of the scion and phenolic composition in Pinot noir berries and wine

Abstract

Context and purpose of the study. Nitrogen (N) limitation enhances the production of phenolic compounds in grapes due to the downregulation of the flavonoid biosynthesis pathway. Grapevine rootstocks influence the N status of the grafted scion through variations in their uptake and assimilation efficiency. However, the extent to which rootstocks regulating the vegetative growth of the scion have an impact on fruit and wine composition remains poorly understood. This study aimed to determine whether the effect of rootstocks on the phenolic composition of Pinot Noir berries and wines is related to the N status of the scion.

Material and methods. A rootstock trial, was planted 2003 in a vineyard of Hochschule Geisenheim University (Germany). The investigation was carried out on Pinot Noir vines grafted onto 17 rootstocks across four field replicates over three vintages (2012–2014). The rootstocks included Riparia Gloire, 5C, 8B, SO4, Binova, 125AA, 420A, Kober 5BB, 110 Richter, 140 Ruggeri, 1103 Paulsen, 41B, 101-14, Schwarzmann, Georgikon 28, Börner, and Rici. Yield, vigor, together with scion N status were recorded using an optical sensor and juice yeast-assimilable nitrogen. Phenolic composition in Pinot Noir berries was analyzed, and micro-scale fermentation was performed to produce wines for each replicate.

Results. While rootstock had no significant effect on Pinot Noir fruit yield (p=0.181), it significantly influenced both vigor and the N status of the scion. Berries from Pinot Noir vines grafted onto rootstocks such as 5C, 420A, 41B, 1103 Paulsen, SO4, and 140 Ruggeri exhibited significantly higher tannin concentrations in both skins and seeds compared to those grafted onto Georgikon, Riparia, 8B, 125AA, and Schwarzmann. However, these differences were not observed in the wines. Anthocyanin concentrations were higher in berries from vines grafted on 8B, 420A, 5C, 41B, and 110 Richter, with this trend translating into wines, showing an inverse relationship with the scion’s N status.

Conclusion. This study highlights the critical interaction between rootstock-driven N uptake efficiency and scion phenolic composition in berries and wines. These findings provide a foundation for selecting rootstocks that align with desired wine profiles and vineyard management objectives.