Comparative study of qualitative and quantitative characters of grape cultivar ‘Mavrodafni’ (Vitis vinifera L.) grown in different regions of the PDO Mavrodafni Patras

The interaction between wine and landscapes is of an unsuspected richness. On the one side, the vineyards form part of the landscapes which they model. On the other side, the wines are related in their perception to the image of a region, a landscape and are at the origin of a cultural richness.

In red wines, anthocyanins evolve during the wine-making process and ageing. They react with other compounds (such as vinylphenols, acetaldehyde, pyruvic acid…) to form a stable family of compounds called pyranoanthocyanins. Furthermore, the oxidation process can modify the anthocyanic profile of a red wine. It is also interesting to evaluate the occurrence of the different subclasses of pyranoanthocyanins and to characterize their chemical properties. The first objective of this study is to evaluate the occurrence of the different groups of pyranoanthocyanins in an oxidised Merlot wine by a centrifugal partition chromatography strategy. The second goal is to evaluate their relative impact in red wines from Bordeaux region by measuring their concentrations.

The strategy of single berry phenotyping is a recently rediscovered research tool that has gained great attention. The latest studies have indicated that previous physiological models based on pooling asynchronous populations of berries provided biased or blurred information on berry development key players. The possibility of monitoring and sampling single synchronized berries to study their development sequentially has opened new lines of research aimed at unraveling the genes that regulate grapevine fruit development. This study aimed to decipher the gene pathways responsible for the activation/deactivation of physiological processes involved in the green phase of growth, the onset of ripening, and the second growth phase.

A Syrah/R99 vineyard in the Stellenbosch area was used. The vineyard is vertically trained and spaced 2.75 x 1.5 m in north-south orientated rows on terroir with Glenrosa soil and west-facing slope. Irrigation (to 100% field water capacity) treatments were applied at different development stages [all stages (including berry set stage); pea size; véraison; post-véraison]. Combined effects of water status and ripeness level were investigated. Preliminary results are presented.

Soil management through cover crops can influence the cycle of nutrients, promote water infiltration, decrease erosion, and enhance the soil microbiota biodiversity, improving the grapevine performance. However, the area under the vines tends to be left bare by applying herbicides or tillage to avoid competition with the crop in semi-arid climates. Use of covers under-vine might be an alternative to these practices aiming at grapevine quality and soil health improvement. The aim of this research was to study the implications of soil management under the vines (cultivation and cover crops) on growth, yield, berry composition and soil microbial communities. A cover crop composed by a mixture of legumes was sown and compared with a control (cultivation), which includes frequent tillage to keep the soil bare, in three areas characterized by different edaphoclimatic conditions in the region of Navarra.