Characterization of varieties named ‘Caiño’ cultivated from Northwest of Spain

Cette communication sera basée sur les résultats d’une étude auprès des consommateurs réalisée par la société G3 pour l’I.N.A.O. sur les attitudes des consommateurs vis à vis des produits de terroir et des A.O.C. et sur un mémoire de DEA soutenu par Monsieur J-C. DURIEUX à l’Université de Paris X Nanterre, consacré aux variables explicatives du comportement d’achat des vins A.O.C.

Antão Vaz is a Portuguese white grapevine variety grown mainly in the wine-growing regions of Southern Portugal, particularly in the Alentejo, Lisbon and Setúbal peninsula regions. It is a very vigorous and productive variety, giving the wines a strong identity. It needs heat and sunlight and prefers deep and dry soils, which makes it tolerant to scald caused by the high summer temperatures of Southern Portugal. However, this variety is very susceptible to downy mildew, caused by plasmopara viticola, a very destructive disease in years with rainy springs.

Water is the main limiting factor for yield in viticulture. Improving drought adaptation in viticulture will be an increasingly important issue under climate change. Genetic variability of water deficit responses in grapevine partly results from the rootstocks, making them an attractive and relevant mean to achieve adaptation without changing the scion genotype. The objective of this work was to characterize the rootstock effect on the diurnal regulation of scion transpiration. A large panel of 55 commercial genotypes were grafted onto Cabernet Sauvignon. Three biological repetitions per genotype were analyzed. Potted plants were phenotyped on a greenhouse balance platform capable of assessing real-time water use and maintaining a targeted water deficit intensity. After a 10 days well-watered baseline period, an increasing water deficit was applied for 10 days, followed by a stable water deficit stress for 7 days. Pruning weight, root and aerial dry weight and transpiration were recorded and the experiment was repeated during two years. Transpiration efficiency (ratio between aerial biomass and transpiration) was calculated and δ13C was measured in leaves for the baseline and stable water deficit periods. A large genetic variability was observed within the panel. The rootstock had a significant impact on nocturnal transpiration which was also strongly and positively correlated with maximum daytime transpiration. The correlations with growth and water use efficiency related traits will be discussed. Transpiration data were also related with VPD and soil water content demonstrating the influence of environmental conditions on transpiration. These results highlighted the role of the rootstock in modulating water deficit responses and give insights for rootstock breeding programs aimed at identifying drought tolerant rootstocks. It was also helpful to better define the mechanisms on which the drought tolerance in grapevine rootstocks is based on.

Red Blotch disease caused by Grapevine red blotch-associated virus (GRBaV) is a severe concern to grape growers and winemakers in major grape-growing regions worldwide. One key aspect of all viruses, including Red Blotch, is their intimate association with cell components and anomalous structures following infection. Therefore, the objective of this study was to analyze symptomatology, vine function, fruit quality and ultrastructure of various tissues and document the relationship of ultrastructural cytopathology with the GRBaV infection in Pinot Noir and Merlot employing various microscopy techniques.

Water resource is a major limiting factor impacted by climate change that threatens grapevine production and quality. Understanding the ecophysiological mechanisms involved in the response to water deficit is crucial to select new varieties more drought tolerant. A major bottleneck that hampers such advances is the lack of methods for measuring fine functioning traits on thousands of plants as required for genetic analyses. This study aimed at investigating how water deficit affects the trade-off between carbon gains and water losses in a large panel representative of the Vitis vinifera genetic diversity. 250 genotypes were grown under 3 watering scenarios (well-watered, moderate and severe water deficit) in a high-throughput phenotyping platform.