Vineyard’s ozone application to induce secondary metabolites accumulation in grapes and wine

One of the main challenges in the wine industry is to understand how different wine processing techniques and practices can influence the overall quality of the final product.

Damage during the budbreak period due to spring season frosts remains one of the most significant weather-related challenges to viticulture around the world. For example, in 2021, €2bn of estimated damage was reported in france while >50% of vineyards were badly affected in the UK in 2017.

Vitis champinii cultivars Ramsey and Dog-ridge are main choices for rootstocks to adapt viticulture in semi-arid and arid regions thanks to their distinctive tolerance to drought and salinity. However, genetic studies on non-vinifera rootstocks have heavily relied on the grapevine (Vitis vinifera) reference genome, which difficulted the assessment of the genetic variation between rootstock species and grapevines. In the present study, this limitation is addressed by introducing a novo phased genome assembly and annotation of Vitis champinii. This new Vitis champinii genome was employed as reference for mapping RNA-seq reads from the same species under drought and salt stresses, and for comparison the same reads were also mapped to the Vitis vinifera PN40024.V4 reference genome. A significant increase in alignment rate was gained when mapping Vitis champinii RNA-seq reads to its own genome, compared to the Vitis vinifera PN40024.V4 reference genome, thus revealing the expression levels of genes specific to Vitis champinii. Moreover, differences in coding sequences were observed in ortholog genes between Vitis champinii and Vitis vinifera, which therefore challenges previous differential expression analyses performed between contrasting Vitis genotypes on the same gene from the Vitis vinifera genome. Genes with possible implications in drought and salt tolerance have been identified across the genome of Vitis champinii, and the same genomic data can potentially guide the discovery of candidate genes specific from Vitis champinii for other traits of interest, therefore becoming a valuable resource for rootstock breeding designs, specially towards increased drought and salinity due to climate change.

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.

Le sol et le climat occupent une place prépondérante dans le concept de terroir, pour lequel l’OIV s’apprête à adopter une définition internationale. Les travaux de recherche qui ont été menés depuis une trentaine d’années sur ces thèmes et qui ont été, pour les plus importants, présentés dans les 7 premiers Congrès Internationaux des Terroirs Viticoles ont considérablement modifié les connaissances sur le fonctionnement des terroirs viticoles dans le monde et le comportement des consommateurs avertis par rapport aux vins de terroirs.