Variation for susceptibility to crown rot and powdery mildew in wild strawberry from North America

Variation for susceptibility to crown rot {Phytophthora cactorum) and to powdery mildew (Sphaerotheca macularis) was observed in a collection of 318 octoploid strawberry plants collected from 37 populations across the Northern United States. The effectiveness of recently developed provenances for octoploid strawberries has been assessed. High susceptibility to powdery mildew was restricted to the Central Mountains provenance, which includes F. virginiana ssp. glauca from the Rocky Mountains and eastern portions of the Cascade Mountains. Populations from the Western Mountain provenance had the highest values for crown rot susceptibility with some overlap into neighbouring populations. The Western Mountain provenance includes F. virginiana ssp. platypetala from the western Cascade mountains and the Olympic Mountains. These data suggest that the provenance partitioning may have some predictive value in identifying areas with horticulturally similar features.