Exploring diversity of grapevine responses to Flavescence dorée infection

Grapevine phylloxera (Daktulosphaira vitifoliae Fitch), controlled by grafting, has re-emerged due to climate change, with shorter hibernation phases, earlier hatching and migrating of hibernales towards the leaves of the vines, and increased reproduction cycles within one season.

Recent advancements in genomic sequencing technologies have enabled more detailed and direct studies of DNA methylation, which can help characterise epigenetic variations in plants. The Grapevine Improvement team at the Bragato Research Institute is studying the use of Oxford Nanopore sequencing to identify epigenetic changes associated with environmental differences among clonally-propagated grapevines.

This study involved sequencing DNA from the same Sauvignon Blanc clone, sourced from diverse New Zealand viticultural regions, using the PromethION platform.

Red wines constitute the majority of the wines produced in Bordeaux. All along the winemaking process, many microorganisms may develop in wine. A lot of them are useful but a common defect found in wine is linked to the development of Brettanomyces bruxellensis, a yeast that produces volatile phenols. These molecules are responsible for an unwanted sensorial defect described as similar to “horse sweat”, “burnt plastic” or “leather”. It has been shown that while some wines are very permissive and easily contaminated, others are pretty resistant to Brettanomyces development. However, common parameters such as pH, alcohol or sugars composition cannot fully explain the differences observed in wine permissiveness.

Toasted pruning vine-shoots represent a promising new enological tool for developing wines with chemical and organoleptic high quality, allowing that the resources of the vineyard to be returned to the wine through a “circular process”.

Les approches du terroir en tant qu’entité géographique (zonages) connaissent un développement accru récent en lien avec l’essor des SIG. Les méthodes, les objectifs et les critères utilisés varient considérablement selon les études.