Characterization of bunch compactness and identification of associated genes in a diverse collection of cultivars of Vitis vinifera L.

Aim: Evaluating the effects of high amount of air injection during red wine fermentation process, on phenolic extraction dynamics, oxygen dissolution, phenolic compounds evolution, and oxidation of red wines.MethodsRed grapes musts were fermented in 100.000 L stainless steel tank, equipped with Parsec SRL “Air mixing” gas injection systems. For this experiment, treatments with two injection regimes, high and low intensity, and high and low daily frequency, were used. Oxygen analyzer was introduced into the tank to evaluate the gas concentration evolution along the fermentation.

ÂThe natural abundance of carbon stable isotopes has been reported to be related to water availability in grapevines quite widely. In the case of nitrogen, the natural abundance of its stable isotopes is mainly affected by the nature of the source of nitrogen (organic vs. inorganic) used by the plant, though the bibliography available for grapevine is very scarce.

The relationship between grape production and leaf surface is a highly debated aspect in terms of the impact it may have on the composition and quality of grapes, especially in areas that focus their cultivation on high-quality wine. In many occasions, the limitation of the unitary production level in these areas is claimed to be the main factor for achieving high quality levels in the wine, forgetting the importance of the source-sink relationship and other environmental factors and management of the canopy. Taking this consideration into account, this work seeks to know the response of the vine as a whole, and the individual shoot as well, to the application of various alternatives of leaves and clusters removal, carried out in the phase immediately before veraison, in cv. Verdejo, in Spain.

Global climate change affects regional climates and hold implications for wine growing regions worldwide. Although winegrowers are constantly adapting to internal and external factors, it seems relevant to develop tools, which will allow them to better define actual and future agro-climatic potentials. Within this context, we develop a modelling approach, able to simulate the impact of environmental conditions and constraints on vine behaviour and to highlight potential adaptation strategies according to different climate change scenarios. Our modeling approach, named SEVE (Simulating Environmental impacts on Viticultural Ecosystems), provides a generic modeling framework for simulating grapevine growth and berry ripening under different conditions and constraints (slope, aspect, soil type, climate variability…) as well as production strategies and adaptation rules according to climate change scenarios. Each activity is represented by an autonomous agent able to react and adapt its reaction to the variability of environmental constraints. Using this model, we have recently analyzed the evolution of vineyards’ exposure to climatic risks (frost, pathogen risk, heat wave) and the adaptation strategies potentially implemented by the winegrowers. This approach, implemented for two climate change scenarios, has been initiated in France on traditional (Loire Valley) and emerging (Brittany) vineyards. The objective is to identify the time horizons of adaptations and new opportunities in these two regions. Carried out in collaboration with wine growers, this approach aims to better understand the variability of climate change impacts at local scale in the medium and long term.

Proteins constitute one of the three main components of grape juice and white wine, phenolic compounds and polysaccharides being the others. A specific group of the total grape-derived proteins resists degradation or adsorption during the winemaking process and remains in finished wine if not removed by the commonplace commercial practice of bentonite fining. While bentonite is effective in removing the problematic proteins, it is claimed to adversely affect the quality of the treated wine under certain conditions, through the removal of colour, flavor and texture compounds. A number of studies have indicated that different protein fractions require distinct bentonite concentrations for protein removal and consequent heat stabilization.