New Fungus-Resistant Grapevine Vitis and V. vinifera L. × M. rotundifolia Derivative Hybrids Display a Drought-Independent Response in Thiol Precursor Levels
Luciana Wilhelm de Almeida, Laurent Torregrosa, Gabriel Dournes, Anne Pellegrino, Hernán Ojeda, and Aurelie Roland*
The use of new disease-resistant grapevine varieties is a long-term but promising solution to reduce chemical inputs in viticulture. However, little is known about water deficit effects on these varieties, notably regarding berry composition. This study is aimed at characterizing the primary metabolites and thiol precursors levels of 6 fungi-resistant varieties and Syrah. Vines were grown under field conditions and under different water supply levels, and harvested at the phloem unloading arrest. A great variability among varieties regarding the levels of thiol precursors was observed, with the highest concentration, of 539 μg/kg, being observed in the 3176-N, a hybrid displaying red fruits. Water deficit negatively and equally impacted the accumulation of sugars, organic acids, and thiol precursors per berry and per plant, with minor effects on their concentration. The observed losses of metabolites per cultivation area suggest that water deficits can lead to significant economic losses for the produce.