Athelia rolfsii에 의한 적갓 흰비단병 국내 최초 발생 보고

초록

In 2023, symptoms of southern blight appeared on the stems and petioles of red-leaf mustard grown in the field at Haman-gun, South Korea. Symptoms of the disease include water-soaking of the lower part of the stem and red-leaf mustard petioles, rot, gradual wilting, and eventually death of the affected plant. White hyphae developed on the stems and petioles of areas in contact with the soil, and many small, brown, round sclerotia were formed. The colonies on potato dextrose agar plates were white, and numerous small, brown, round sclerotia were formed over time. The size of the sclerotia was 1 to 3 mm, and the width of the hyphae was 4 to 9 µm. The optimal temperature for hyphal growth and sclerotia formation was 30℃. Additionally, clamp connections were observed in the hyphae. As a result of molecular identification using sequence analysis and phylogenetic analysis of the ITS rRNA region, the causative fungus was identified as Athelia rolfsii. In pathogenicity tests, 6 days after inoculation, the stems and petioles of red-leaf mustard showed water-soaking, and these areas gradually rotted. Sclerotia on the white hyphal mats were abundantly formed at the inoculation site. No symptoms were induced in the negative control. Additionally, pathogen re-isolation was performed to fulfill Koch's postulates. This study is the first report of southern blight caused by A. rolfsii on red-leaf mustard in Korea. It is expected to provide valuable information for epidemiological investigation of disease outbreaks and establishment of disease management strategies.

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