Powdery mildew (PM) of strawberry (Fragaria ×ananassa), caused by the obligate parasite Podosphaera aphanis syn., is a major fungal disease of strawberry crops all over the world.
This disease is particularly severe in the humid environments of covered, small tunnels and greenhouses. Marked variation in the susceptibility of different strawberry cultivars to PM and a high heritability of PM resistance have been reported in strawberry breeding populations. This implies a great potential for the breeding of new cultivars with enhanced disease resistance.