Grapevine performances in five areas of ‘Chianti Classico’ Comportement de la vigne en cinq zones des « Chianti Classico »

A critical aspect of wine quality is the overall expression of wine flavour, which is formed by the interplay of volatile aroma compounds, their precursors, and taste and matrix components.
Grapes directly contribute to wine only a small number of potent aroma compounds, and the unique
sensory attributes and perceived quality of a wine result from combining 100s of metabolites of grapes, yeast and bacteria, and oak wood.

Long-term studies on grapevine phenology have clearly demonstrated that global warming is affecting phenological events, leading to an anticipation in their timing, and negatively impacting grape yield and berry quality. Therefore, dissecting the genetic determinants involved in the plant regulation of the phenological stages of budburst, flowering, veraison and ripening can improve our knowledge of the underlying mechanisms and support plant breeding programs and the advancement of vineyard management strategies.
We report here the results of a QTL mapping experiment conducted on three segregating populations obtained from the crossing of ‘Cabernet Sauvignon’ and ‘Corvina’, ‘Corvina’ and the hybrid ‘Solaris’ and ‘Rhine Riesling’ and ‘Cabernet Sauvignon’.

The management of oxygen during winemaking and aging is a big issue in order to achieve high quality wines. The correct amount of O2 improves aroma, astringency, bitterness and color, however an excess of oxygen promotes the appearance of yellow

Measurement of carbon isotope discrimination in berry juice sugars at maturity (δ13C) provides an integrated assessment of water use efficiency (WUE) during the period of berry ripening, and when collected over multiple seasons can be used as an indication of drought stress response. Berry juice δ13C measurements were carried out on 48 different varieties planted in a common garden experiment in Bordeaux, France from 2014 through 2021 and were paired with midday and predawn leaf water potential measurements on the same vines in a subset of six varieties. The aim was to discriminate a large panel of varieties based on their stomatal behaviour and potentially identify hydraulic traits characterizing drought tolerance by comparing δ13C and hydroscapes (the visualisation of plant stomatal behaviour as a response to predawn water potential). Cluster analysis found that δ13C values are likely affected by the differing phenology of each variety, resulting in berry ripening of different varieties taking place under different stress conditions within the same year. We accounted for these phenological differences and found that cluster analysis based on specific δ13C metrics created a classification of varieties that corresponds well to our current empirical understanding of their relative drought tolerances. In addition, we analysed the water potential regulation of the subset of six varieties (using the hydroscape approach) and found that it was well correlated with some δ13C metrics. Surprisingly, a variety’s water potential regulation (specifically its minimum critical leaf water potential under water deficit) was strongly correlated to δ13C values under well-watered conditions, suggesting that base WUE may have a stronger impact on drought tolerance than WUE under water deficit. These results give strong insights on the innate WUE of a very large panel of varieties and suggest that studies of drought tolerance should include traits expressed under non-limiting conditions.

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.