Search for recessive resistance genes to downy and powdery mildew in grapevine for the development of durable resistance varieties.

Downy and powdery mildew are important diseases of grapevine (Vitis vinifera), mainly managed with pesticides.Although dominant resistance genes from wild Vitis species have been introgressed into cultivated grapevine genetic background, their durability remains limited.Alternative strategies, such as recessive resistance genes, have proven effective in other species, offering a promising path to long-term disease control.Given the high heterozygosity of grapevine, we hypothesize that alleles conferring recessive resistance may already exist within the V. vinifera gene pool.In such a case, self-fertilization of a susceptible V. vinifera variety would result in approximately 25% of individuals showing resistance.