Effects of hormone- and natural-based elicitors at the transcriptomic level in berries of cv. Tempranillo

Global warming is one of the biggest environmental, social, and economic threats. In the Douro Valley, change to the climate are expected in the coming years, namely an increase in average temperature and a decrease in annual precipitation. Since vine cultivation is extremely vulnerable and influenced by the climate, these changes are likely to have negative effects on the production and quality of wine.
Adaptation is a major challenge facing the viticulture sector where the choice of plant material plays an important role, particularly the rootstock as it is a driver for adaptation with a wide range of effects, the most important being phylloxera, nematode and salt, tolerance to drought and a complex set of interactions in the grafted plant.
In an experimental vineyard, established in the Douro Region in 1997, with four randomized blocs, with five varieties, Touriga Nacional, Tinta Barroca, Touriga Franca and Tinta Roriz, grafted in four rootstocks, Rupestris du Lot, R110, 196-17C, R99 and 1103P, data was collected consecutively over 20 years (2001-2020). Phenological observations were made two to three times a week, following established criteria, to determine the average dates of budbreak, flowering and veraison. During maturation, weekly berry samples were taken to study the dynamics of sugar accumulation, amongst other parameters. Climate data was collected from a weather station located near the vineyard parcel, with data classified through several climatic indices.
The results achieved show a very low coefficient of variations in the average date of the phenophases and an important contribution from the rootstock in the dynamic of the phenology, allowing a delay in the cycle of up to10-12 days for the different combinations. The Principal Component Analysis performed, evaluating trends in the physical-chemical parameters, highlighted the effect of the climate and rootstock on fruit quality by grape varieties.

Evidence for a specific effect of soil mineral composition on wine character is largely anecdotal. However, soil potassium supply to the vine must be properly balanced between deficiency and excess for good fruit quality.

Soil management through cover crops in the lines of the vineyards is a common practice in viticulture, since it improves the characteristics of the soil. It has been shown that the cover crops can influence the cycle of nutrients, promote infiltration, decrease erosion, and enhance the soil microbiota biodiversity improving the grapevines. However, the area under the vines tends to be left bare by applying herbicides or tillage to avoid competition with the crop in hot climates. The use of cover crops under the vines might be a plausible alternative to the use of herbicides or cultivation, improving grapevine quality and soil characteristics. The aim of this research was to study the implications of different management of the soil under the vines (herbicide, cultivation or cover crops) on grapevine growth, water and nutritional status and belowground microbial communities.

The phenolic profiles of little known red grape cultivars, namely Garnacho, Moribel and Tinto Fragoso, which are autochthonous from the Spanish region of La Mancha (ca. 600,000 ha of vineyards) have been studied over the consecutive seasons of years 2013 and 2014. The study was separately performed over the skins, the pulp and the seeds, and comprised the following phenolic types: anthocyanins, flavonols, hydroxycinnamic acid derivatives (HCADs), total proanthocyanidins (PAs) and their structural features. The selected grape cultivars belong to the Vine Germplasm Bank created in this region in order to preserve the great diversity of genotypes grown in La Mancha.

Acetaldehyde is a common component of wine. It is already formed during the fermentation being an intermediate in the production of ethanol. Moreover, it can derive from the oxidation of ethanol during the wine production and aging. In wine, concentrations of acetaldehyde range from 30 to 130 mg/L. Acetaldehyde in wine can react with many compounds such as SO2, amino acids and