Ten grapevine rootstocks: effects on vegetative development, production and grape quality of cv. Mencia in the d.o. Bierzo (Spain)

In this study for the first time, eight natural stilbenes (trans-resveratrol, trans-piceid, cis-piceid, trans-astringin, trans-piceatannol, (+)-trans-s-viniferin, pallidol and hopeaphenol) isolated and purified from Vitis vinifera, were simultaneously separated and analysed within 5 mn by ultra high pressure liquid chromatography coupled with photodiode array detection.

The increased intensity and frequency of heatwaves, coupled with prolonged periods of drought, are a significant threat to viticulture worldwide. During these conditions the more exposed leaves can show visible symptoms of heat damage. We monitored the functionality of photosystem II (PSII) in the field to better understand the impact of heatwaves on canopy performance. A factorial experiment was established in summer 2023 using Shiraz grapevines in the Barossa valley of South Australia, involving water-stressed and well-watered vines.

Vineyards face climate change, increasing temperatures, and drought affecting vine water status. Water deficit affects plant physiology and can ultimately decrease yield and grape quality when it is not well managed. Monitoring vine water status and irrigation can help growers better manage their vineyards.

The undergoing global warming scenario is affecting grapevines phenology, including the timing of berry ripening and harvest date, negatively impacting production and quality. This work reports the crucial role of NAC61, a grapevine NAC transcription factor, in regulating metabolic processes occurring from the onset of ripening onwards. NAC61 high confidence targets mainly represent genes acting on stilbene biosynthesis and regulation, and in osmotic and oxidative/biotic stress-related responses. The direct regulation of the stilbene synthase regulator MYB14, the osmotic stress-related gene DHN1b, and the Botrytis cinerea susceptibility gene WRKY52, were all further validated.

As the climate warms, the focus of concern in viticulture often turns to how higher temperatures may shift growing regions, change the character of AVAs, and alter fruit quality. However, climate warming is increasing most quickly during the winter dormancy cycle, a critical and often underappreciated portion of the grapevine life cycle. In response to decreasing temperatures and decreasing daylength, grapes initiate a series of physiological changes to enter dormancy, acquire freeze resistance, and time spring phenology such that the growing season begins after threat of frost.