Controlling Fungal Diseases of Garden Rose Foliage: Towards Valorization and Labeling of Genetic Resources for Reduced Phytosanitary Inputs

Garden roses suffer aesthetic damage and heavy fungicide use due to two foliar pathogens: Podosphaera pannosa (powdery mildew) and Diplocarpon rosae (black spot). This study developed controlled‐condition infection assays and conducted genetic analyses in an interspecific rose population. Despite challenges in preserving the powdery mildew pathogen, assays for black spot were successful. Analyses revealed three QTLs associated with black spot resistance and one major QTL for powdery mildew resistance. The recently sequenced rose genome now allows the identification of candidate resistance genes within these QTL regions. Further functional studies are necessary to confirm these genes and support the breeding of low‐input, disease‐resistant rose varieties.