Vineyard microclimate alterations induced by black mulch through transcriptome reshaped the flavoromics of Cabernet Sauvignon

Aims: Some of the most direct effects of climate variability on grapevines are the changes in the onset and timing of phenological events and in the length of the growing season, which may affect grape quality. The aim of this research was to analyze the projected changes in vine phenology and on grape composition of the Tempranillo variety in Rioja DOCa under different climate change scenarios.

Wine complexity is considered a multidimensional yet equivocal sensory percept. This project uncovered sensory attributes Australian Chardonnay wine consumers associate with Chardonnay wine complexity
and correlations between expert and consumer perceived wine complexity and preference. A
wine consumer test examined 6 Australian Chardonnay wines of three complexity levels designated low (LC1&2), medium (MC1&2), and high (HC1&2) by an expert panel (n = 8) using a benchtop sensory task. Consumers (n = 81) rated their perceived liking using a 9-point hedonic scale; wine complexity with a 5-point scale anchored “low”, “low-medium”, “medium”, “medium-high”, and “high” and lastly, profiled the wines using Rate-All-That-Apply (RATA). Psychographic segmentation with the Fine Wine Instrument
(FWI) generated three segments; Wine Enthusiasts (WE n=29), Aspirants (ASP n=40) and No- Frills (NF n=12).

Today, there is need to design, produce and label terroir wines, with unique organoleptic properties and more “attractive to consumers”. For this purpose, two Saccharomyces cerevisiae yeast strains (Sa and Sb) isolated during spontaneous fermentations were used for white wine production from the Assyrtiko grape of Santorini. A third commercial strain was used as control.

The Douro Demarcated Region, in Northern Portugal, offers outstanding wines with unique characteristics. Due to the today’s globalized marketplace, local producers often need to further develop their cultivation techniques to remain competitive. The Association of Viticultural Development in the Douro Valley (ADVID) works as a unit of experimentation, offering services and training to meet the demands of the Douro’s vitiviniculturists.

In the last decades, climate change required already adaptation of vineyard management. Increase in temperature and unexpected weather events cause changes in all phenological stages requiring new management tools. For example, defoliation can be a useful tool to reduce the sugar content in the berries creating differences in the wine profiles. In a ten-year field experiment using Riesling (Vitis vinifera L, planted 1986, Geisenheim, Germany), various mechanical defoliation strategies and different intensities were trialed until 2016 before the vineyard was uprooted. Wood was sampled from the plant compartments root, trunk, cordon and shoot for analyses of physicochemical properties (e.g. lignin and element content, pH, diameter), nonstructural carbohydrates and the microbial communities. The aim of the study was to investigate the influence of reduced canopy leaf area on the sink-source allocation into different compartments and potential changes of the fungal and prokaryotic wood-inhabiting community using a metabarcoding approach. Severe summer pruning (SSP) of the canopy and mechanical defoliation (MDC) above the bunch zone decreased the leaf area by 50% compared to control (C). SSP reduced the photosynthetic capacity, which resulted in an altered source-sink allocation and carbohydrate storage. With lower leaf area, less carbohydrates are allocated. This for example resulted in a decreased trunk diameter. Further, it affected the composition of the grapevine wood microbiota. SSP and MDC management changed significantly the prokaryotic community composition in wood of the root samples, but had no effect in other compartments. In general, this study found strong compartment and less management effects of the microbial community composition and associated physicochemical properties. The highest microbial diversities were identified in the wood of the trunk, and several species were recorded the first time in grapevine.