Breeding for durable resistance to downy and powdery mildew in grapevine

Sabine Wiedemann-Merdinoglu,Didier Merdinoglu,Emilce Prado,Christophe Schneider,Pere Mestre

doi:10.20870/oeno-one.2018.52.3.2116

Sabine Wiedemann-Merdinoglu, Didier Merdinoglu + Show 3 more

Open Access

https://doi.org/10.20870/oeno-one.2018.52.3.2116

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Abstract

The current strategy to control grapevine downy and powdery mildew relies on chemical treatments. An alternative solution to the use of chemicals is the development of varieties resistant to pathogens. Several genetic factors derived from Vitis species closely related to cultivated grapevine and conferring protection against downy mildew or powdery mildew have already been identified. Nevertheless, many major resistance genes have been overcome by virulent strains of pathogens in various plant-pathogen interactions, and such resistance breakdowns have already been described in grapevine. Resistance genes are a limited resource, and their introduction in a new variety is a long-term and costly process. This is why the assessment and improvement of resistance durability is crucial, particularly in the case of a perennial species. The Inra-ResDur breeding program aims at creating varieties with durable resistance to downy and powdery mildew. The pyramiding strategy employed to limit the risk of resistance breakdown is described. Other innovative ways are proposed to enhance resistance durability.

Highlights

The current strategy to control grapevine downy and powdery mildew relies on chemical treatments
As Vitis species closely related to cultivated grapevine have already been shown to be potential sources of resistance, an alternative solution to the use of chemicals is the development of varieties resistant to pathogens (Boubals, 1959; Staudt and Kassemeyer, 1995; Cadle-Davidson, 2008)
That is why Inra (French National Institute for Agricultural Research) decided in 2000 to launch a breeding program to create varieties combining durable resistance to downy and powdery mildew with berry quality suitable for the production of high quality wines (Merdinoglu et al, 2009). The use of these resources in breeding programs is not trivial, partly because the varietal ideotype is complex and must meet several objectives in order to have a commercial future: display a high level of resistance to the two major diseases, downy and powdery mildew; show at least partial resistance to diseases that may emerge in the absence of phytosanitary treatments; provide effective and durable resistance; and display a berry composition compatible with the production of high quality wines in a context of climate change