The interplay between grape ripening and weather anomalies – A modeling exercise

Worldwide, with an average of 6.7 million cultivated hectares, of which exclusively 51% in Europe (faostat, 2021), the production of table and wine grapes is a leading sector, with continued growth in Europe in the area devoted to vine cultivation. during the growing season, most of the plant organs can be susceptible to several fungal and oomycete diseases, leading to important economic losses and causing detrimental effects on fruit quality. the increasingly scarce availability of fungicidal products, often also related to their relative impact on the environment, coupled with the emergence of resistance in the pathogen to these products, make defence increasingly challenging.

Grapevine (Vitis spp.) is a globally significant fruit crop, and enhancing its agronomic and oenological traits is crucial to meet changing agricultural conditions and consumer demands. Conventional breeding has played a key role in domesticating grapevine varieties, but it is a time-consuming process to develop new cultivars with desirable traits for cultivation.
New plant breeding techniques (NpBTs) offer a potential revolution in grapevine cultivation, and genome editing has shown promise for targeted mutagenesis. The success of these biotechnological approaches relies on efficient in vitro regeneration protocols, particularly through somatic embryogenesis (SE).

Grapevine interspecific hybrids (PIWIs, from German “pilzwiderstandsfähige Rebsorten” meaning fungus tolerant grapevine cultivars), offer a promising alternative to traditional cultivars in many wine regions due to their tolerance to certain fungal diseases. This makes them a potential solution for sustainable wine production, particularly under organic systems. Despite extensive research on certain agronomic traits and susceptibility to biotic diseases, such as powdery and downy mildews, the response of these cultivars to abiotic stressors, such as drought, remains unclear. Our study aims to investigate the eco-physiological traits of two commercial PIWI cultivars, Muscaris and Souvignier gris, at the leaf level to evaluate their response to drought stress.

Climate change is increasing the frequency of water deficit in many grape-growing regions. Grapevine varieties differ in their stomatal behavior during water deficit, and their ability to regulate water potential under dry soil conditions is commonly differentiated using the concept of isohydricity. It remains unclear whether stomatal behavior, water potential regulation, and the resulting degree of isohydricity has a relationship with changes to fruit growth during water deficit. This study was conducted on four varieties (`Cabernet Franc`, `Semillon`, `Grenache`, and `Riesling`) subjected to both short-term, severe water deficit and long-term, moderate water deficit applied at both pre- and post-veraison.

It is often said that wine is a complex matrix and the chemical analysis of wine with the thousands of compounds detected and often measured is proof. New technologies can assist not only in separating and identifying wine compounds, but also in providing information about the sample as a whole. Information-rich techniques can offer a fingerprint of a sample (untargeted analysis), a comprehensive view of its chemical composition. Applying statistical analysis directly to the raw data can significantly reduce the number of compounds to be identified to the ones relevant to a particular scientific question. More data can equal more information, but also more noise for the subsequent statistical handling.