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(Stachys sieboldii) in Jinju, Korea. White colonies were present on leaves and petioles. Severely infected lesions were discolored, being brown. In the present study, the morphological features of anamorphic and teleomorphic Korean specimens were studied. To complete the identification, the sequence of the internal transcribed spacer region of the ribosomal RNA gene(ITS rRNA) was analyzed. Based on morphological characteristics, including anamorphic and teleomorphic features, as well as analysis of the ITS rRNA gene region, the fungus associated with the symptoms was identified as Neoerysiphe galeopsidis. Although the host ranges of powdery mildew caused by N. galeopsidis has been previously recorded, no full description or illustration of fungal symptoms and signs on Japanese artichoke has yet appeared. To the best of our knowledge, this is the first full description of powdery mildew disease on Japanese artichoke featuring molecular identification, morphological features, symptoms, and signs in Korea.