White blister, white rust. White or yellowish sporangial pustules (blisters), often in concentric groups and often confluent, mainly on lower surface of leaves, also on petioles and flowers, sometimes causing hypertrophy.
Morphology
Sporangiophores 30-45 x 15-18 µm, non-septate, hyaline. Sporangia in basipetal chains (oldest at top), globose to oval, 12-18 µm diam., hyaline, thin-walled. Oospores rarely found in leaves, usually in stems, globose, brownish, 30-55 µm diam., wall thick, tuberculate with low blunt ridges that are often confluent and irregularly branched.
Notes Recent molecular studies have enabled distinct species to be separated from Albugo candida sens lat. However, it has also been found that A. candida sens. str. has a wide host range within the Brassicaceae and also extends to the closely related Cleomaceae and Capparaceae (Choi, et al., 2007).
