Interactions « Terroir x Vigne » : facteurs de maîtrise du micro-environnement et de la physiologie de la plante en rapport avec le niveau de maturité et les éléments de typicité

Context and purpose of the study. Intra-varietal variability for key physiological and oenologically important traits can be exploit in viticulture following the consistently higher environmental pressure driven by climate change.

Flow cytometry (FCM) is a powerful technique allowing the detection, characterization and quantification of microbial populations in different fields of application (medical environment, food industry, enology, etc.). Depending on the fluorescent markers and specific probes used, FCM provides information on the physiological state of the cell and allows the quantification of a microorganism of interest within a mixed population. For 15 years, the enological sector has shown growing interest in this technique, which is now used to determine the populations present (of interest or spoilage) and the physiological state of microorganisms at the different stages of winemaking.

Preliminary experiment of harvest timing was carried out in Eger wine district, Hungary in 2009. In situ physiological responses, berry quality parameters and wine quality of the Kékfrankos grapevine were studied at two growing sites (Eger-K6lyuktet6 – non-stressed, flat vineyard, and Eger-Nagyeged hill – water stressed, steep slope vineyard).

Actually, many countries around the world are studying different strategies for adapting winegrowing regions to climate changes, focusing on a sustainable viticulture.

Botrytis cinerea is a fungus that causes common infection in grapes and other fruits. In winemaking, its presence can be both considered desirable in the case of noble rot infection or undesirable when grey rot is developed. This fungus produces an extracellular enzyme known as laccase which is able to cause oxidation of phenolic compounds present in must and wine, causing most of the times a decrease in its quality and problems during the winemaking process [1]. Material and methods: Three B. cinerea strains (B0510, VA612 and RM344) were selected and grown in a liquid medium adapted from one previously described [2]. The enzyme was isolated by tangential ultrafiltration of the culture medium using a QuixStand system equipped with a 30 KDa filtration membrane.