うどんこ病
Oidium mangiferae is a plant pathogen that infects mango trees causing powdery mildew. Powdery mildew of mango is an Ascomycete pathogen of the Erysiphales family that was initially described by Berthet in 1914, using samples collected from Brazil. "O. mangiferae" is found in all areas where mangoes have been raised long term, but is particularly widespread in India where both the host and the pathogen are native. Currently no teleomorph stage has been identified, but due to certain morphological characteristics it has been suggested that "O. mangiferae" belongs in the "Erysiphe" polygony group. Mango is the only known host for this pathogen, though "O. mangiferae" appears to be identical to fungi responsible for powdery mildew diseases on various other plant species, particularly oak, though some differences may be observed. In particular, the number of cells in conidiophores varies from 2 on mango to 3-5 on oak. "O. mangiferae" has been known to infect oak leaves in the laboratory, however due to the lack of a known telemorph stage "O. mangiferae" is still considered to only be a pathogen of mango. Recent analysis of its ribosomal DNA suggests it is conspecific with "Erysiphe alphitoides", the causative agent of powdery mildew in European oaks.