Morphological and Molecular Identification of Powdery Mildew caused by Neoerysiphe galeopsidis on Stachys sieboldii Miq.

Abstract

From August to October 2013, a powdery mildew was found on Japanese artichoke(Stachyssieboldii) in Jinju, Korea. White colonies were present on leaves and petioles. Severely infectedlesions were discolored, being brown. In the present study, the morphological features ofanamorphic and teleomorphic Korean specimens were studied. To complete the identification, thesequence of the internal transcribed spacer region of the ribosomal RNA gene(ITS rRNA) wasanalyzed. Based on morphological characteristics, including anamorphic and teleomorphicfeatures, as well as analysis of the ITS rRNA gene region, the fungus associated with thesymptoms was identified as Neoerysiphe galeopsidis. Although the host ranges of powderymildew caused by N. galeopsidis has been previously recorded, no full description or illustrationof fungal symptoms and signs on Japanese artichoke has yet appeared. To the best of ourknowledge, this is the first full description of powdery mildew disease on Japanese artichokefeaturing molecular identification, morphological features, symptoms, and signs in Korea.