Ability of Saccharomyces cerevisiae strains to modulate the aroma of albariño wines

Insufficient levels of malate and lack of acidity in commercial grape cultivars (V.vinifera) hinders the quality of fruit grown in warm climates. Conversely, excessive levels of malate and sourness in wild Vitis grape, leads to unpalatable fruit and complicates the introgression of valuable disease resistant alleles through breeding. Nonetheless, albeit decades of research, knowledge regarding the molecular regulation of malate levels in grape remains limited.

A set of Syrah plots covering a wide range of terroirs distributed in the vineyards of the Rhone Valley and the Mediterranean South is examined through their oenological and sensory characteristics. The multidimensional analysis of data leads to the following groupings: (1) A group of unstructured wines with a simple aromatic profile dominated by fruity-floral notes; they come from plots where the ripening conditions have been disturbed by unfavorable climatic conditions, or an excess harvest.

Aerial thermography has emerged as a promising tool for water stress detection in grapevines, but there are still challenges associated with this technology, particularly concerning the methodology employed to extract reliable canopy temperature values. This consideration is relevant especially in vertically trained vineyards, due to the presence of multiple surfaces which are captured by drone thermal cameras with high-resolution. To test the technology and the data analysis required, a field study was conducted during the 2022-2023 season in a model vineyard with multiple scions-rootstock combinations trained on a vertical shoot-positioning (VSP) system. Additionally, three irrigation regimes were implemented to introduce variability in water stress levels.

Plants have evolved different strategies to cope with environmental stresses and, although still debated, it was observed that they can remember past stress occurrence.
Anatomical and physiological adjustments have been observed in different grapevine cultivars after repeated drought exposure, however epigenetic, transcriptional and biochemical changes associated with drought-primed ecological memory have been poorly studied.
This work was conceived to test whether exposure to recurring events of mild drought could prime vines to endure severe drought stress. Particularly, we investigated whether the expected improved stress tolerance of Vitis vinifera cv Nebbiolo plants subjected over years to moderate and long-lasting water stress events (WS-primed) depended on molecular memory phenomena or on resetting of stress-induced signals.

The gradual change in rainfall patterns experienced in the south of France vineyards, especially around the Mediterranean sea, means that the vines are increasingly subject to summer drought. The winegrowers developped the use of irrigation techniques to ensure the maintenance of competitive yields in the production of wines under Protected Geographical Indication label. In practice, drip irrigation pipes can be installed above the ground or buried into the soil as well as at different distances from the vine row. The objective of this study was to examine the profiles of the wet bulbs of the soil obtained from two drip irrigation systems : aerial drip located under the vine row and subsurface drip placed in the middle of the inter-row. This experiment took place over two consecutive seasons (2020-2021) on a 3.4 ha Viognier plot in the Mediterranean region (PGI Oc, France) on sandy clay soil. The annual rainfalls were less than 400 mm. Soil water content probes were installed at different depths (20 – 40 – 60 – 80 cm) and at different lateralities from the vine row (30 – 60 – 90 – 120 cm) to control the formation of the soil wet bulb during irrigation. The mapping and the analysis of the data allowed a better understanding and differentiation of the water percolation when irrigating with subsurface or aerial drip. For the same amount of water and without differences of vine water status, it is shown that in a subsurface drip irrigation situation, the size of the wet bulb formed is larger than in aerial drip irrigation system.