First report of powdery mildew caused by Leveillula taurica on Cucurbita ficifolia in Korea.
During routine field surveys in October and November 2014, unusual symptoms of leaf chlorosis or yellowing were observed on fig-leaf gourds (Cucurbita ficifolia) planted in 2 experimental plastic houses in Iksan, Korea Republic. Symptoms included chlorosis of the adaxial leaf surface and white fungal colonies on the abaxial leaf surface. Chlorotic lesions were mostly angular but not completely vein-limited, suggesting some differences from typical downy mildew symptoms. Microscopic observation revealed the lesions to be associated with a powdery mildew. No chasmothecia were found over the course of the season. The causal pathogen was isolated and identified as Leveillula taurica based on morphological, molecular and pathogenicity analyses. The resulting 766 bp sequence was deposited in GenBank (accession no. MH698492). This is thought to be the first report of L. taurica on C. ficifolia globally as well as in Korea Republic.