Méthodologie pour application et valorisation des études de terroir dans les caves cooperatives des Côtes du Rhône (France)

In 1979, the so-called “french paradox” was proposed, that is, a correlation between wine consumption, a diet rich in saturated fats, and a low mortality from coronary heart disease. On the other hand, it has also been described that alcohol consumption has negative effects on aging and increases the risk of liver cirrhosis and cancer. However, both hypotheses are based on population studies that may present distortions due to multiple factors (geographic, diet, smoking, socioeconomic level, etc.).

l lavoro presenta l’evoluzione dei contenuti di arsenico nelle uve durante lo sviluppo e la maturazione, e la sua distribuzione nell’acino; verifica inoltre la relazione tra i contenuti di As nelle uve

The perception of wine quality is determined by the assessment of multiple sensory stimuli, including aroma, taste, mouthfeel and visual aspects. With so many different parameters contributing to the overall perception of wine quality, it is important to consider the contribution of all metabolites in a wine when attempting to relate composition to quality.

In the last decades, climate change required already adaptation of vineyard management. Increase in temperature and unexpected weather events cause changes in all phenological stages requiring new management tools. For example, defoliation can be a useful tool to reduce the sugar content in the berries creating differences in the wine profiles. In a ten-year field experiment using Riesling (Vitis vinifera L, planted 1986, Geisenheim, Germany), various mechanical defoliation strategies and different intensities were trialed until 2016 before the vineyard was uprooted. Wood was sampled from the plant compartments root, trunk, cordon and shoot for analyses of physicochemical properties (e.g. lignin and element content, pH, diameter), nonstructural carbohydrates and the microbial communities. The aim of the study was to investigate the influence of reduced canopy leaf area on the sink-source allocation into different compartments and potential changes of the fungal and prokaryotic wood-inhabiting community using a metabarcoding approach. Severe summer pruning (SSP) of the canopy and mechanical defoliation (MDC) above the bunch zone decreased the leaf area by 50% compared to control (C). SSP reduced the photosynthetic capacity, which resulted in an altered source-sink allocation and carbohydrate storage. With lower leaf area, less carbohydrates are allocated. This for example resulted in a decreased trunk diameter. Further, it affected the composition of the grapevine wood microbiota. SSP and MDC management changed significantly the prokaryotic community composition in wood of the root samples, but had no effect in other compartments. In general, this study found strong compartment and less management effects of the microbial community composition and associated physicochemical properties. The highest microbial diversities were identified in the wood of the trunk, and several species were recorded the first time in grapevine.

Le comportement de la vigne est étroitement lié aux propriétés hydriques des sols surtout dans leurs parties profondes.