INTERREG WIVITIS PROJECT

Context

Reducing the use of pesticides and adaptation to climate change are the two major challenges facing modern agriculture, with viticulture being particularly sensitive to them. To avoid the massive use of pesticides, several national varietal selection programs have been set up to create varieties resistant to the main fungal diseases of grapevines (commonly known as PIWIs). To date, these programs have succeeded in generating several downy and powdery mildew-resistant varieties with high oenological and agronomic qualities.  Remarkably, the ResDur program at INRAE Colmar is at the forefront of the national varietal selection strategy, successfully creating varieties that are increasingly gaining popularity in different French vineyards.

The current challenge is to bring climate change into the equation. The WiVitis project aims to understand the ability of PIWIs to cope with climate change and the predicted increase in disease pressure coming along with it. To achieve this goal, WiVitis brings together French, German and Swiss scientific and viticultural partnerships from the transnational Upper Rhine region. The WiVitis project is co-financed by the European Union as part of the Interreg Upper Rhine 2021-2027 program.

Objectives

The primary objective of WiVitis is to strengthen cross-border cooperation and promote the exchange of data and materials to better organize responses to the adverse effects of climate change on viticulture in the Upper Rhine region.

From a scientific point of view, WiVitis studies grapevine-pathogen interactions with a focus on aspects linked to climate change. These include the resilience of berries to extreme climatic conditions, and experiments combining pathogens with heat stress. The choice of biological material used for WiVitis is based on a collection that includes emblematic local varieties and PIWIs selected in the Upper Rhine region, while the targeted diseases are downy mildew (caused by Plasmopara viticola) and grey mold (caused by Botrytis cinerea).

WiVitis Activities at INRAE Colmar

The INRAE Colmar center is at the heart of WiVitis, coordinating a workpackage that involves the GMV, GAV teams and the ‘Unité d'Expérimentation Agronomique et Viticole’ (UEAV).

Research activities are organized along two axes:

1) Study of grape skin composition in relation to Botrytis susceptibility.

Botrytis-infected berries of different varieties (PIWI and traditional) (Figure 1) are subjected to metabolic analyses in order to understand the molecular determinants of resistance or susceptibility at the cuticular level. To this end, we have developed a method for extracting cuticular lipids from grapes, as well as a method for separating and identifying metabolites of interest using liquid chromatography coupled with high-resolution mass spectrometry.

Figure 1: Representative photos of the resistance of berries of different varieties to Botrytis cinerea infection. Berries were incubated for 14 days under conditions favorable to the pathogen.

2) Study of the impact of heat stress on the physiology and resistance of PIWIs to downy mildew.

To this end, we are currently developing a platform to simulate one of the most devastating phenomena of climate change: heat waves. During the 2024 summer, a prototype was validated (Figure 2). For the 2025 season, the objectives are to setup larger experiments and to validate an operational protocol combining downy mildew infection and heat stress.

Figure 2: Left: detail of heat wave simulation prototype. Top right: thermal photos showing the temperature difference between control and heat-stressed plants. Bottom right: graph showing leaf temperatures of control plants (blue line) and treated plants (red line) during a test with a +10°C difference between control and treatment. X axis: time (date). Y axis: temperature in degrees Celsius.

Main parterships

• Germany: Julius Kühn-Institut Siebeldingen (JKI), Dienstleistungzentrum Ländlicher Raum Rheinpfalz, Staatliches Weinbauinstitut Freiburg (WBI)
• France: INRAE Grand Est – Colmar
• Switzerland: Forschungsinstitut für biologischen Landbau (FiBL), Swiss Nanoscience Institute (University of Basel)

Associated parterships

• Germany: Rebschule Freytag
• France: Institut Français de la Vigne et du Vin (IFV)
• Switzerland: Agroscope, Canton du Jura, Kanton Basel-Stadt, Kanton Aargau, Basel Landschaft, Auer Rebschule