About PIWI Grapes
Contact UsPIWI NewsMembershipIssuesResearchWine AwardsPIWI PedigreeTermsQuestions
Who?What?Where?Why?PIWI Grape Varieties
German PIWIsItalianCzechUS HybridsFrench SwissHungaryWhat is a PIWI Grapevine?
As the German word “pilzwiderstandsfähig” translates to “fungus resistant,” that is the key to PIWI grapevines. The fungus resistance comes from crossing Vitis vinifera with other Vitis species (V. rupestris, V. amurensis, V. rotundifolia, etc.) that have natural genetic resistance to powdery mildew (Oidium/Erysiphe necator) and downy mildew (Peronospora/Plasmopara viticola).
Aren’t These Just Hybrid Grapes?
The short answer is yes, but these are fourth, fifth and even sixth-generation hybrids, so they are not the grapes your parents were drinking. It is a fact that many of the new PIWI grapes contain 80 to 90% Vitis vinifera genetics, and because of this, the German government legally defines these grapes as Vitis vinifera. Even France is working on modern hybrid grapevines.
Tradition breeding was a long process, taking 20 or more years to select a new variety. With the development of improved laboratory tests, breeders can identify the grapevines with the resistance markers and focus their attention on those vines. Once you know that they have the resistance genetics, the research can focus on berry quality and plant growth habits, both important characteristics.
Powdery Mildew (E. Necator)
Downy Mildew
The Genetics
Powdery: Run1 Ren1 Ren3 Ren4 Downey: Rpv1, Rpv3.X, Rpv10 & Rpv12
