Identification of Podosphaera xanthii as the causal agent of powdery mildew disease affecting Echinacea purpurea in Korea

In-Young Choi1,2   Sun-Hee Hong3   Yong-Ho Lee3   Hyeon-Dong Shin4,*   

1Department of Agricultural Biology, Jeonbuk National University, Jeonju 54896, Korea
2Institute of Agricultural Science and Technology, Jeonbuk National University, Jeonju 54896, Korea
3Department of Plant and Environment Science, Hankyong National University, Anseong 17579, Korea
4Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Korea

Abstract

During the extensive forays for discovering the biodiversity of phytopathogenic fungi in Korea, powdery mildew-affected purple coneflowers (Echinacea purpurea) were frequently found. Since 2004, nine samples have been deposited in the Korea University Herbarium. The initial symptoms include white, evanescent mycelia and irregular patches on mature leaves. Mild symptoms in the form of discolored lesions are also noticed on the stem and petal of the affected plants. Based on the morphological characteristics of the anamorph and the phylogenetic analysis of the internal transcribed spacers (ITS) and large subunit (LSU) rDNA sequences, the causal fungus was identified as Podosphaera xanthii. This is the first report that identifies the causal agent of powdery mildew disease affecting purple coneflower in Korea.

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