Characterization of variety-specific changes in bulk stomatal conductance in response to changes in atmospheric demand and drought stress

Viticulture worldwide is currently affected by the effects of climate change. This set of adverse phenomena lead to a deterioration of functional vine mechanisms, affecting growth, physiology and grape ripening, which may cause severe losses with respect to yield and quality. To prevent water stress and other abiotic factors from severely affecting its physiology, the vine’s response is to reduce transpiration and photosynthesis rates. This response varies depending on the cultivar and its ability to adapt to the environment. The hydroscape method is based on the internal regulation of water status in the plant. It has been recently used to classify grapevine genotypes according to their iso/anisohydric behavior when they are subjected to water stress conditions.

“Terroir” has been acknowledged as an important factor in wine quality
and style. It can be defined as an interaction between climate, soil, vine (cultivar, rootstock) and human
factors such as viticultural and enological techniques. Soil and climate are the two components of the “Terroir” with an important role on the vine development and berries ripening. The present study is focused on the effects of the weather conditions and the soil characteristics on the phenological and berries ripening dynamics of the “Touriga Nacional” in Dão region.

The C-glycosidic ellagitannins constitute a subclass of hydrolyzable tannins of remarkable structural diversity. In this work we first achieved the hemisynthesis of flavano-ellagitannins, then we used them to develop a new efficient detection and quantification procedure for the C-glycosidic ellagitannins as well as flavano-ellagitannins.

Drought caused by climate change has a dramatic incidence on the vineyard. Despite employing specific rootstocks tolerant to drought like 110 Richter, the vineyard continues to experience various losses, revealing the importance of the scion cultivar in the adaptation to drought stress. In this regard, Merlot, a widely cultivated grapevine, exhibited reduced drought tolerance compared to less cultivated varieties like Callet, a local cultivar originating from the Balearic Islands that demonstrated greater resilience to drought. Therefore, understanding the drought stress response in both cultivars and the cross-talk between scion and rootstock is key to unveiling possible differences that could affect to the adaptation to drought in vineyard.

In view of increasing drought frequencies due to climate change, enhancing grapevine resilience to water scarcity has become vital for sustainable viticulture.