Effect of bearing position on phenolics profiles in the skins of four cultivars of grapevine (Vitis vinifera L.)

Abstract

SummaryThe fan-shaped trellis training system, resulting in grapevines (Vitis vinifera L.) with more than two trunks, has been widely used in northern China. The fruiting zone of grapevines trained to the fan-shaped trellis system is distributed from the top to the bottom of the canopy. The phenolics profiles of the skins of ‘Cabernet Sauvignon’, ‘Merlot’, ‘Chardonnay’, and ‘Italian Riesling’ grape berries were analysed to measure the effect of differences in bearing position on the phenolic compound and anthocyanin compositions of grape berries.The results showed that the upper bearing position significantly increased the concentrations of most phenolic compounds in grape berry skins. Among the non-anthocyanin and anthocyanin phenolic compounds identified in this study, the upper bearing position promoted the accumulation of delphinidin-, cyanidin-, and petunidin-glucosides in the skin of the two red grape cultivars. However, lowering the bearing position was associated with greater methylation of anthocyanins, and the flow of photosynthate towards the biosynthesis of kaempferol. These results were correlated with micrometeorological alterations in the canopy at the different bearing positions. The findings of this study suggest that higher bearing positions can increase the accumulation of phenolic compounds in grape berry skins in four different grapevine cultivars.