SSR analysis of some Vitis sylvestris (GMEL.) accessions of the Szigetköz and Fertő-hanság national park, Hungary

Nitrogen (N) supply strongly influences vine productivity and berry composition, matching availability and uptake requirements of vines during the growing season is essential to optimize vine nutrition. The nutritional status of grapevines is commonly assessed by the determination of petiole nutrient concentrations at flowering. The reserve N could also be an earlier indicator for grapevine N status, this work aimed to assess how the petiole levels relate to these perennial N reserves.

Using grapevine genetic diversity is one of the strategies to adapt viticulture to climate change. In this sense, assessing the plasticity of cultivars in their responses to environmental conditions is essential. For this purpose, the drought tolerance of Grenache, Tempranillo and Semillon cultivars grafted onto SO4 was evaluated at two experimental vineyards, one located in Valencia (Spain) and the other in Bordeaux (France). This was done by assessing gas exchange parameters, water relations and leaf hydraulic traits at the end of the season.

Several classes of flavonoids, such as anthocyanins, flavonols, flavanols and flavones, undergo a slow H/D exchange on aromatic ring A, leading to full deuteration at positions C(6) and C(8). Within the flavanol class, H-C(6) and H-C(8) of catechin and epicatechin are slowly exchanged in D2O to the corresponding deuterated analogues; even quercetin, a relevant flavonol representative, shows the same behaviour in a D2O/DMSOd6 1:1 solution. Detailed kinetic measurements of these H/D scrambling processes are here reported by exploiting the time-dependent changes of their peak areas in the 1H-NMR spectra taken at different temperatures. A unifying reaction mechanism is also proposed based on our detailed kinetic observations, even taking into account pH and solvent effects. Molecular modelling and QM calculations were also carried out to shed more light on several molecular details of the proposed mechanism.

Environmental factors like soil and climate influence grape quality potential. Their impact is often mediated through vine water and nitrogen status. Depending on the color of the grapes (red or white) and the type of wine produced, the desired level of vine water and nitrogen status for optimum wine quality is different. Little investigation has been carried out concerning these factors and their potential influence on sparkling wine quality on two vintages. In this study vine water and nitrogen status were assessed at a very high density and related to grape composition and berry weight. Through statistical analyses, the major factors driving grape quality potential on Pinot noir in Champagne were highlighted.

Etant lié au sol et aux conditions atmosphériques, le statut hydrique influence la physiologie de la vigne d’une part, mais joue aussi un role important en ce qui concerne la qualité du raisin et donc du vin d’autre part. Nous avons mesuré, dans la région de Stellenbosch, le statut hydrique sur des pieds de Sauvignon Blanc non irrigués, implantés sur 2 terroirs différents, l’un froid, l’autre plus chaud.