The importance of soil and geology in tasting terroir; a case history from the Willamette valley, Oregon

Downy mildew, a disease caused by Plasmopara viticola (Berk. et Curt.) Berl. and De Toni, is one of the strongest threats to grapevine (Vitis vinifera L.) production. Recently, sources of resistance to downy mildew were identified among Caucasian germplasm. Among them, the Georgian variety Mgaloblishvili revealed a unique resistance mechanism. A genome wide association study (GWAS) allowed the identification of the genetic bases of Mgaloblishvili resistance, the loci Rpv29, Rpv30 and Rpv31. To dissect the three resistance loci, Mgaloblishvili genome was sequenced using PacBio HiFi reads and assembled.

Grafting Vitis vinifera L. (wine traditional cultivars) onto North American grapevine species or hybrids is a common practice in viticulture given their tolerance against phylloxera (Daktulosphaira vitifoliae). However, rootstock genetic background affects the response of grapevines to environmental stresses and their ability for establishing a symbiotic relationship with the microbial communities, and more specifically with arbuscular mycorrhizal fungi (AMF).
The aim of this study was to evaluate Monastrell variety (clone ENTAV 369) grafted onto three rootstocks (140Ru, 110R and RG8) characterized by a different genetic background, in combination with AMF inoculation (Rhizophagus irregularis) vs. a non-inoculated control with regards to vegetative growth, leaf gas exchange parameters, and mycorrhization.

Phenolic compounds are secondary metabolites of grapes. Plants produce a wide variety of this type of metabolites through diverse biosynthesis pathways and their production is sometimes a response to external stimuli, either environmental or biotic stresses. Some of them may act as chemical defenses against pathogens or herbivores and their synthesis is increased when the attack exists. However, it is remarkable that the synthesis of these interesting compounds can be activated even when the stimulus is not present, with the use of elicitors. These are substances that when applied exogenously trigger the biosynthetic pathways conducting to the synthesis of these defense compounds.

Aromatic characteristics of wines are strongly influenced by agronomical and enological factors, depending of the climate, cultivar and winemaking process. Tropical wines are a new concept of vitiviniculture that is being developped in the Northeast of Brazil since the 80’s, located between 8-9º latitude of the South Hemisphere, where the second most important cultivar used for reds is Tempranillo. In this condition, vines produce grapes and enologists elaborate wines twice a year, because high temperatures, solar radiation and water availability for irrigation.

The capture and valorization of fermentative CO2 have been developed for several years by the company w platform for internal uses, notably in the cellars: inerting, cooling, reduction of water consumption, extraction, with aroma valorization. In a context of climatic warming during the vegetative cycle, grapes are currently harvested with a significant sugar concentration, a phenomenon that is expected to intensify in the coming decades. The high alcohol content of the resulting wines goes against the demand of customers who are seeking high-quality wines with less alcohol.