Podosphaera clandestina causes powdery mildew on sour cherry in Iran

Abstract

During 2014–2016, symptoms and signs of a powdery mildew disease were observed on the leaves and twigs of sour cherry (Prunus cerasus) in orchards from Firouragh in the Khoy region (West Azarbaijan province) of Iran. Young leaves and twigs were covered with a powdery growth consisting of mycelium and the asexual reproductive structures of a powdery mildew species. Affected leaves were curled upward and smaller than uninfected leaves, while affected twigs were stunted and often defoliated. The fungus was identified as belonging in the genus Podosphaera, based on morphological characteristics of its asexual state. Chasmothecia were not observed. The PCR amplification and sequencing of its ITS-rDNA revealed that the causal agent was Podosphaera clandestina. This is the first record on the occurrence of P. clandestina on sour cherry in Iran.