Soils, climate and vine management: their influence on Marlborough Sauvignon blanc wine style

Studies on model plants have shown that temporary soil flooding exposes roots to a significant hypoxic stress resulting in metabolic re-programming, accumulation of toxic metabolites and hormonal imbalance. To date, physiological and transcriptional responses to flooding in grapevine are poorly characterized. To fill this gap, we aimed to gain insights into the transcriptional and metabolic changes induced by flooding on grapevine roots (K5BB rootstocks), on which cv Sauvignon blanc (Vitis vinifera L.) plants were grafted.

Conserving and exploring the intra-varietal diversity of ancient varieties is essential to foster their use in the future, preserving the traditions and history of ancient growing regions and their wines. The conservation of representative samples of ancient varieties and the utilization of intra-varietal variability through polyclonal selection are advisable strategies to save and promote the cultivation of each variety, respectively.

The unique characteristics of terroir play a fundamental role in shaping the identity and quality of wines, influencing the aromatic complexity of young wines and their long-term aging potential. The volatile compounds responsible for these aromas are crucial to identifying and appreciating a given wine.

Grapevine breeding is part of the research program of Agroscope in Switzerland since 1965. From 1965 to 1995, the aim of the Vitis vinifera crosses was to obtain a high resistance to grey rot (Botrytis cinerea), one of the most virulent fungal pathogens in the Swiss vineyard. In 2021, the grape varieties released from this first breeding program covered 936 ha of the 15’000 ha of the Swiss vineyard.
In 1996, a second breeding program aimed at obtaining, by classical interspecific hybridization, grape varieties resistant to downy mildew (Plasmopara viticola) and powdery mildew (Erisyphe necator) and less sensitive to grey rot (Botrytis cinerea). In order to accelerate and make the selection process more reliable, an early biochemical test was developed based on the natural defense mechanisms of the vine against downy mildew (stilbene phytoalexins). The synthesis of stilbenes (i.e., resveratrol and its oxidized dimers - and -viniférine) and pterostilbenes (methylated derivative) is among the most efficient induced defense mechanisms of grapevine against fungal pathogens on both the leaves and the clusters.

Winegrowers must adapt more and more their viticultural practices in order to evolve toward a sustainable viticulture, to be competitive and to improve both the production methods and the quality and typicalness of wines. In this context, ‘Terroir’ studies in Loire Valley vineyards have allowed to build decision aid maps that can be used directly by growers to adjust their practices.