Estimation of plant hydraulics of grapevine in various «terroirs» in the Canton of Vaud (Switzerland)

Grapevine (Vitis vinifera L.) is a challenging plant species to transform and regenerate due to its complex genome and biological characteristics. This limits the development of cisgenic and gene-edited varieties. One hurdle is selecting the best starting tissue for the transformation process, much like isolating suitable tissue for protoplasts. One promising method involves delivering CRISPR/Cas components to protoplasts isolated from embryogenic calli, which are then induced to regenerate. However, this process is inefficient, time-consuming, and only applicable to a few genotypes. To enhance grapevine regeneration efficiency, the expression of developmental and plant growth regulators shows promise in escaping the recalcitrance encountered in traditional tissue culture methods.

Phosphonic acid and especially potassium dihydrogen phosphonate are widely used to restrain the ubiquitous pressure of grapevine downy mildew in viticulture. Nevertheless, phosphonic acid and its derivatives have been banned in organic viticulture in October 2013, because they have been classified as plant protection products since then.

The plant rhizosphere microbial communities are an essential component of plant microbiota, which is crucial for sustaining the production of healthy crops. The main drivers of the composition of such communities are the growing environment and the planted genotype. Recent viticulture studies focus on understanding the effects of these factors on soil microbial composition since microbial biodiversity is an important determinant of plant phenotype, and of wine’s organoleptic properties. Microbial biodiversity of different wine regions, for instance, is an important determinant of wine terroir.

The mechanical strength or firmness of a fruit is considered an important parameter to characterize its state of maturity or conservation, as other parameters such as sugar level or color.

Vegetative growth and yield are reported to affect grape and wine quality. They can be controlled through different techniques linked to vine management. The objective of this research was to determine the effect of vine vigour and number of clusters per vine on physicochemical composition and phenolic profile of red wines. The experiment was carried out during two vegetative cycles, with cv. Cabernet Sauvignon grafted onto Paulsen 1103. Three vine vigour were defined, according to shoot weight at previous harvests, being low, medium and high. Five treatments of number of clusters were used for each vigour, with 15, 22, 29, 36, and 45 clusters per vine. Grapes from all treatments were harvested in the same day from Brix and total acidity criteria. Thirty days after bottling, classical analyzes and phenolic compounds were performed. As results, different responses were obtained from each vintage. In 2020, a dry season from veraison to harvest, grapes and wines obtained from low vigour treatment and 45 clusters per vine was the highest in sugar and alcohol content respectively, while grapes and wines from high vigour and 15 clusters presented the lowest sugar and alcohol content. Total anthocyanins were higher in treatment with low vigour and 15 clusters, while the lowest amounts were found in low vigour with 45 clusters, as well as medium and high vigour with 36 clusters per vine. Total tannins were higher in high vigour with 22 clusters and medium vigour with 29 clusters, while were lower in low vigour with 36 clusters. In 2021, a wet season at harvest, responses were different, and great variations were observed between treatments. As conclusions, yield and vine vigour had strong influence on grape and wine quality, promoting different enological potentials on which can be indicated/used for aging strategies of red and even rosé wines.