Discovering the process of noble rot: fungal ecology of grape berries during the noble rot transformation in different vineyards of the Tokaj wine region

Grape quality potential for wine production is strongly influenced by environmental parameters and agronomic factors. Several studies underline the rootstock effect on scions vegetative growth and berry composition [1] with an impact on wine quality. Rootstocks are promising agronomic tools for climate change adaptation and in most grape-growing regions the potential diversity of rootstocks is not fully used and only a few genotypes are planted. Moreover, little is known about the effect of rootstock genetic variability on the aromatic composition in wines.

The wine industry is increasing the demand for indigenous yeasts adapted to the terroir to produce unique wines that reflect the distinctive characteristics of each region. In our group, we have identified and characterized 60 native yeast strains isolated from a vineyard in Maldonado-Uruguay, in which three strains stood out: Saccharomyces cerevisiae T193FS, Saturnispora diversa T191FS, and Starmerella bacillaris T193MS. Their oenological potential was evaluated at a semi-pilot scale in Tannat must vinification in the wine cellar to have a more precise and representative evaluation of the final product.

In recent years, Mediterranean regions are being affected by marked climate changes, primarily characterized by reduced precipitation, greater concurrence of temperature extremes and drought during the growing season, and increased inter-annual variability in temperatures and rainfall. Generally, high-quality red wines need moderate water deficit. Hence, irrigation may be needed to avoid severe vine water stress occurring in some vintages and soils with low holding capacity. The aim of this work was to evaluate the effects of soil recharge irrigation in pre-sprouting and summer irrigation every week (30 % ETO) from the pea size state until the end of ripening (RP) compared to exclusively summer irrigation every week (R) in the same way that RP, on must volatile composition at harvest.

Due to climate change, the occurrence of heatwaves and drought events is increasing, with significant impact on viticulture. Common ways to adapt viticulture to a changing climate include site selection, genotype selection, irrigation management and canopy management. The latter mentioned being for instance source-sink manipulations, such as leaf removal, with the aim to delay ripening.

Grapevine vigour, defined as the propensity to assimilate, store and/or use non-structural sugars for allowing fast growth of shoots and producing large canopies[1], is crucial to optimize vineyard management. Recently, a model has been proposed for predicting the vigor of young grapevines through the measurement of the vegetative growth and physiological parameters, such as water status and gas exchange[2]. Our objectives were (1) to explore the influence of the association of two grapevine varieties (Tempranillo and Cabernet Sauvignon, grafted onto R110 rootstocks) with arbuscular mycorrhizal fungi (AMF) on the vegetative vigour of young plants; and (2) to assess the effect of environmental factors linked to climate change on the vegetative vigour of Cabernet Sauvignon.