Climatic zoning and viticulture in Galicia (North West Spain)

The Pomerol vineyard, located 35 km east of Bordeaux, covers around 800 ha on the left bank of the Isle. There is a system of fluvial terraces with more or less coarse gravel and pebble spreading, resting on a Tertiary substratum ranging from the Middle to Upper Eocene to the Lower Oligocene (Dubreuilh, 1993). This interweaving of terraces of varying thickness results in a brutal superposition of differentiated materials which give rise to various types of soil. Several site studies in this sector of the Libounais show significant morphological and analytical differences from one point to another (Guilloux et al ., 1978; Duteau, 1982; Van Leeuwen et al.., 1989). The distribution of the soils of the Pomerol vineyard was studied and resulted in a cartography at 1/25000th (Merouge, 1995).

Water tolerance in plants is often associated with the accumulation of osmotic protectants, which are secondary metabolites that can help the plant to cope with water stress. One of the key osmotic protectants is a sugar called Raffinose, which is synthesized by a family of enzymes called Raffinose synthases. In this work, we focused on one of these enzymes, VviRAF2, which is a gene that shows different expression levels and genetic variants (SNPs) among different grapevine cultivars, ranging from tolerant to susceptible to water stress, and the transcription factors that may regulate the expression of this gene family.

Les travaux menés, dans le cadre du programme départemental pour la connaissance et la valorisation des terroirs viticoles, sur l’aire A.O.C. Coteaux du Languedoc / Pic Saint-Loup ont permis d’appliquer à l’échelle d’une Appellation d’Origine Contrôlée (13 communes), une méthodologie d’étude axée sur les aspects sol/climat/topographie qui concourent à l’identification des terroirs naturels, facteurs de typicité des vins.

Controlling the development of the bacterial population during the winemaking process is essential for obtaining correct wines[1]. Carbonic Maceration (CM) wines are recognised as high-quality young wines. However, due to its particularities, CM winemaking implies a higher risk of bacterial growth: lower SO2 levels, enrichment of the must in nutrients, oxygen trapped between the clusters… Therefore, wines produced by CM have slightly higher volatile acidity values than those produced by the destemming/crushing method[2].

The quality of wine is assessed, among other things, by its color, which is mainly due to its anthocyanin content. These pigments are polyphenols that give red, purple and blue hues depending on the relative proportion of anthocyanins produced by the action of flavonoid 3’5′ hydroxylase (delphinidin-3-glucoside, petunidin-3-glucoside, malvidin-3-glucoside) or flavonoid 3′ hydroxylase (cyanidin-3-glucoside, peonidin-3-glucoside). To study the genes involved in this biosynthetic pathway, we focused on Vitis vinifera cv. Tannat, known for producing wines with higher anthocyanin content and darker purple color compared to most red grape varieties. In this work, we have performed RNA-Seq analysis of skins during berry development, taking green and red berries at 50% veraison as separate samples, as an experimental strategy to focus on the differential expression of genes of interest.