Microbial metagenomics of vineyard soils and wine terroir

Climate change is here. One of the main consequences is an increase in the frequency and severity of abiotic stresses which mostly occur in a combined manner. Grapevine, which grows in a large diversity of pedo-climatic conditions, has presumably evolved different mechanisms to allow this widespread adaptation. Harnessing the genetic diversity in these mechanisms will be central to the future of viticulture in many traditional wine growing areas. The interactions between the scion and the rootstock through grafting add an additional level of diversity and adaptive potential to explore.
At the physiological level, these mechanisms are related to processes such as root system development and functioning (water and nutrient uptake), interactions with the soil microbiome, gas exchange regulation, hydraulic properties along the soil-plant-atmosphere continuum, reserve storage, short and long distance signaling mechanisms and plasticity for some of these traits.

Planting vineyards in cooler climates has been used over recent years as
a strategy to counter the climatic shifts caused by climate change. A move towards higher altitudes in hilly and mountainous wine regions may provide a solution to deleterious effects that increased ambient temperatures have on wine quality. Until now, the influences of higher altitudes and their climates, as well as their effect on vine growing cycles, still holds a lot of scientific uncertainty. The transnational EU-funded project REBECKA (Interreg V-A IT-AT: ITAT1002, duration: 2017-2019) has the objective to develop a regional valuation method to rate the suitability for viticulture in South Tyrol (Italy) and Carinthia (Austria). Preliminary surveys were performed regarding the effects of altitude on ripening performance of the cultivar Pinot Noir.

Changes in the low molecular weight phenolic fraction, obtained by liquid-liquid microextraction technique, were studied after controlled oxidation of two typologies of Sangiovese wines (Brunello di Montalcino and Chianti Classico) belonging to two vintages (2017 and 2018). The fractions were characterized by LC-MS and quantified by HPLC. The most abundant extracted compounds were the phenolic acids. The effect of oxidation, vintage, and wine typology was stated by a three-ways ANOVA. Gallic and syringic acids significantly increased after oxidation while (–)-epicatechin decreased the most.

The aim of this study is to provide an overview of the terroir of Saint-Romain, Burgundy, based on three main information sources: official data relating to vines (CVI), soil cartography and a survey of winegrowers’ practices.

Sfursat di Valtellina is a DOCG reinforced wine produced in Valtellina from partially withered red grapes of Vitis vinifera L. cv. Nebbiolo. The grape ripeness degree and the dehydration process strongly influence the physicochemical characteristics of grapes [1, 2, 3]. In particular, grape skin and seeds contain several classes of phenolic compounds strictly associated with red wine quality, which are significantly affected by these factors [4]. The aim of this research is to assess the combined influence of different ripeness levels and withering rates on the standard chemical composition and phenolic profile of winegrape in order to provide new insights and approaches to the management of withering, searching for the valorization of grape potentialities.