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Home • Exobasidium maculosum A7-4 v1.0
Exobasidium leaf spot of blueberry. Photo by Marin Brewer.
Exobasidium leaf spot of blueberry. Photo by Marin Brewer.
E. maculosum infection on blueberry fruit. Photo by Marin Brewer.
E. maculosum infection on blueberry fruit. Photo by Marin Brewer.
Yeast-like growth of E. maculosum on PDA. Photo by Marin Brewer.
Yeast-like growth of E. maculosum on PDA. Photo by Marin Brewer.

Exobasidium maculosum is an emerging pathogen of blueberry (Vaccinium spp.) in the southeastern United States and northeastern North America. This dimorphic basidiomycete causes Exobasidium leaf and fruit spot on several commercial blueberry species and interspecific hybrids. It grows as a saprotrophic, budding yeast or as a biotrophic, filamentous parasite. Although it causes a recently emerging disease, studies show that populations are geographically structured and that genetic diversity is very high, which both suggest that the emergence is not due to a recent introduction. Members of the genus Exobasidium are host specialized and cause perennial and systemic shoot and leaf deformities, including localized annual leaf spots and blisters, witch’s brooms and galls on leaves, shoots and flowers when infecting members of the Ericales. Species are delimited based on host and disease phenotype. There are over 150 described species within the genus Exobasidium.

Genomic analysis of E. maculosum will provide insight into the genes underlying host-pathogen interactions and host manipulation, as well as dimorphism, and the saprophytic and pathogenic lifestyles. Additionally, the genetic basis of disease emergence, elevated genetic diversity, species divergence and ecological adaptation can be investigated.