Petiole phosphorus, magnesium and sulphur concentrations are controlled by rootstocks with Vitis riparia genetic background in grapevine

Backgrounds and aims: Grapevine, Vitis vinifera, requires grafting on Phylloxera tolerant rootstocks of American origin in most viticultural areas of the world. The most commonly used species in rootstock creation are V. berlandieri, V. riparia and V. rupestris. Rootstocks not only provide tolerance to Phylloxera but assure the supply of water and mineral nutrients to the scion. The objective of this work was to determine to what extent rootstocks of different genetic backgrounds alter the mineral composition of petioles of grapevine. Methods and results: Vitis vinifera cv. Cabernet Sauvignon was grafted onto 13 rootstock genotypes and planted in a vineyard in three blocks. The concentration of 13 mineral elements was determined in the petioles at veraison (berry softening). Genetic background of rootstocks has a significant effect on petiole mineral composition. Rootstocks with at least one V. riparia genetic background reduced the concentration of phosphorus and magnesium and increased the concentration of sulphur in the petiole of Cabernet Sauvignon. Conclusion: Rootstocks with a V. riparia genetic background generally confer low scion vigour and we have shown that they also confer low petiole phosphorus concentration; this could suggest that phosphorus uptake and use is related to known rootstock conferred vigour in grapevine. Significance of the study: This is the first study to demonstrate a significant link between the genetic background of a rootstock genotype and its ability to regulate scion phosphorus, magnesium and sulphur content, in field conditions.