New technologies to characterize spatial variability in viticulture

The notion of «terroir» refers to the link between the composition, quality and taste of a wine, on the one hand, and its place of origin, on the other. It involves, among other things, the signature of soil elements, as well as the influence of climatic conditions and plant material used. The composition of the wine is also influenced by the winemaking, storage and bottling processes. We were lucky enough to have a time series of the same champagne, from the end of the first world war to the present. On this exceptional time series, we followed, with the most advanced methods, all the elemental signatures by isotopic multi-dilution, the evolution of the isotopic ratios of heavy elements with very high precision of Sr, Pb, B and Cu.

Actually, many countries around the world are studying different strategies for adapting winegrowing regions to climate changes, focusing on a sustainable viticulture.

In a recent context where consumers pay an increasing attention to sustainability and eco-friendly aspects in the decision-making process, the use of the resistant varieties in the wine sector have returned to the attention. In this context, the use of mould-resistant grape varieties would be an opportunity for sparkling wine producers as it can reduced the pesticide utilization in grape management and hence production costs.
However, the use of the resistant varieties to produce the base wine may be strongly influenced due to its requirements for a particular balance between sugars and acidity to ensure the quality of the final product. In addition, the aromatic profile of base wine plays a crucial role in the perception of the quality of the sparkling wine.

Developments in high-throughput sequencing (HTS) technologies allow us to obtain large amounts of microbial information from wine and must samples. Thus approaches, that are aimed at characterising the microbial diversity during fermentation, can be enhanced, or possibly even replaced, with HTS-based metabarcoding. To reduce experimental biases and increase data reproducibility, we compared 3 DNA extraction methods by evaluating differences in the fungal diversity with Riesling alcoholic fermentation samples at four different vineyards. The fungal diversity profiling was done using the genetic markers ITS2 and D2 using metabarcoding. The extraction methods compared consisted of a commercial kit, a recently published protocol that includes a DNA enhancer, and a protocol based on a buffer containing common inhibitor removal reagents. All methods were able to distinguish vineyard effects on the fungal diversity, but the results differed quantitatively.

Berry Shrivel (BS, Traubenwelke) is a sugar accumulation disorder of grapevine of unknown causes, having a great negative impact on grape quality and incalculable risks for yield losses, and for which no reliable curative practices are available.