Veraison as determinant for wine quality and its potential for climate adapted breeding

Anthocyanins are responsible for the red wine color and their ability to condense with tannins is considered as a contributor in astringency reduction. However, recent studies showed the possibility of anthocyanins to influence directly the in-mouth perception of wines.

The precise molecular mechanisms underlying the domestication of grapevine (Vitis vinifera L.) Are still not fully understood. In the recent years, next-generation sequencing (NGS) of plastid genomes has emerged as a powerful and increasingly effective tool for plant phylogenetics and evolution. To uncover the biological profile of the grapevine domestication process comprehensively, an investigation should encompass both the cultivated varieties (V. vinifera subsp. Vinifera) and their wild ancestors V. vinifera subsp. Sylvestris) across all potential sites of their distribution and domestication.

Vine water status was measured on 96 plots of three vines inside a vineyard block of 0.28 ha during three years: 2003, 2004 and 2005. Three physiological indicators were implemented: stem water potential, carbon isotope discrimination measured on grape sugars at ripeness (δ13C) and canopy temperature measured by high resolution remote sensing. For stem water potential, measurements were taken on every single vine of each plot.

Grape anthocyanin content and composition could affect the quality and the production strategies of red wines. Differences in the pigment composition modify the color properties in terms of hue, extractability and stability. Thus, for the production of a highly qualitative wine such as “Amarone”, variations in the pigment composition are not negligible. The aim of this work was the investigation of the anthocyanin profile changes during ripening in Corvina grapes, the main cultivar for the “Amarone” production. The experiment took place in 2015, in two vineyards located in Valpollicella (Italy).

The grape maturation process is being affected by the consequences of global climate change and, as a result, there is a gap at harvest time between the technological maturity of grapes (mostly the concentration of sugar and acids) and its phenolic quality. Due to this gap, the wines elaborated using those grapes show a non-adequate phenolic composition, which results in defects on its color and astringency characteristics. Astringency is mainly related to the salivary protein precipitation because of the interaction not only with wine flavanols but also with other wine phenolics, such as flavonols or different pigments.