Investigating the role of endophytes in enhancing grapevine resilience to drought

Pruning is one essential vineyard management activity whose main purpose is to regulate plant growth and vigour, modulating berry size, and consequently, wine quality. In Chilecito, La Rioja Province, Argentina, Torrontés Riojano stands as the only autochthonous variety for winemaking, yielding golden and aromatic berries and distinctive muscatel-tasting wines. This white cultivar, resulting from the natural cross between Moscatel de Alejandría x Criolla Chica, is traditionally trained in “parral” (horizontal trellis system), aimed to manage vigorous canopies. This project constitutes the first study on the influence of pruning intensity on Torrontés Riojano growth habit and berry quality.

The Ability of PVPP (Polyvinylpolypyrrolidone), PVP-DEGMA-TAIC (copolimerization of N-vinyl-2-pyrrolidinone with ethylene glycol dimethacrylate and triallyl isocyanurate) and PAEGDMA
(poly(acrylamide-co-ethylene glycol dimethacrylate)) polymers was tested as removal agents for Fumonisin B1 (FB1) and Fumonisin B2 (FB2) from model solutions and red wine. The polymers removal capacity was checked at three different resident times (2, 8 and 24 hours of contact time between the polymer and the sample), showing no differences in the percentage of FB1 and FB2 removal. Then, different polymer concentrations (1, 5 and 10 mg mL-1) were tested in model solution with and without phenolics (i.e. gallic acid and 4-methylcatechol).

Tannin, anthocyanins and their reaction products play a major role in the quality of red wines. They contribute to their sensory characteristics, particularly colour and astringency. Grape tannins and anthocyanins are extracted during red wine fermentation. However, their concentration and composition change over time, due to their strong chemical reactivity1. It is also well known that yeasts influence the wine phenolic content, either through the release of metabolites involved in the formation of derived pigments1, or through polyphenol adsorption2,3.

The components and methodology for characterization of the terroir have been described by Gómez-Miguel & Sotés (1993-2014, 2003) and Gómez-Miguel (2011) taking into account the full range of environmental factors (i.e: climate, lithology, vegetation, topography, soils, altitude, etc.), landscape variables (derived from photo-interpretation and a digital elevation model), and specific variables to the country’s viticulture (i.e: size and distribution of the vineyards, varieties, phenology, productivity, quality, designation regulations, etc.).

The study of new wine grape cultivars can be interesting to diversify the local wine productions without using international varieties. With this aim some Vitis vinifera intraspecific crosses obtained by Prof. Dalmasso in the 1930s and registered in the Italian National Catalogue in 1977, have been studied in the last years.