Evaluation of the resistance mechanisms of new fungus-resistant grape varieties

Evaluation of the resistance mechanisms of new fungus-resistant grape varieties and their influence on the potential savings in plant protection


Project duration: November 2018 to October 2021

Funded by the Forschungsring des Deutschen Weinbaus (FDW)
This project is being worked on as part of a doctoral thesis by Chantal Wingerter


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Viticulture worldwide is based on European wine varieties. However, these are highly susceptible to the American pathogens, powdery mildew and downy mildew, which were introduced in the 19th century. This problem requires the massive use of fungicides or copper preparations to reduce the enormous crop yield losses.
One way to reduce the use of fungicides is to increase the cultivation of fungus-resistant grape varieties ("Piwis"). To this end, resistance properties against powdery and downy mildew from American or Asian wild grape varieties have been introduced into susceptible European grape varieties through long-term crossing programs. The cultivation of such new varieties can improve the development of viticulture with regard to factors such as sustainability, resources and environmental protection.

In this project, new fungus-resistant grape varieties are being tested for their resistance to powdery and downy mildew. Various plant protection variants for Piwis with different resistances are being tested and the infestation intensity and frequency of powdery and downy mildew are being determined over three years. Based on the results, recommendations for action are to be given that contribute to the sustainability of plant protection in Piwis, to sensibly reduce the input of fungicides in viticulture and thus support the cultivation of these varieties.

Furthermore, the resistance mechanisms of selected fungus-resistant grape varieties to downy mildew will be investigated. The findings of the different defense mechanisms and the resistance loci involved should contribute to a better understanding of the molecular basis and, based on this, to evaluate the stability and durability of the defense mechanisms against aggressive isolates of downy mildew in order to ensure sustainable resistance management and breeding.