doi: 10.4489/KJM.520207 Citation BibTeX RIS Mendeley

Peltaster fructicola: Undescribed Sooty Blotch and Flyspeck Species on Apple Fruit in Korea

Peltaster fructicola: Undescribed Sooty Blotch and Flyspeck Species on Apple Fruit in Korea

• Jun-Woo Choi (Department of Plant Medicine, Kyungpook National University, Daegu 41566, Korea)
• Seong-Keun Lim (Department of Plant Medicine, Kyungpook National University, Daegu 41566, Korea)
• Seo-Ryeong Lee (Department of Plant Medicine, Kyungpook National University, Daegu 41566, Korea)
• Chang-Gi Back (Department of Environmental Horticulture and Landscape Architecture, Environmental Horticulture, Dankook University, Cheonan 31116, Korea)
• In-Kyu Kang (Department of Horticultural Science, Kyungpook National University, Daegu 41566, Korea)
• Seung-Yeol Lee (Institute of Plant Medicine, Kyungpook National University, Daegu 41566, Korea)
• Hee-Young Jung (Institute of Plant Medicine, Kyungpook National University, Daegu 41566, Korea)

While investigation of the fungal diseases on apples collected from Cheongsong-gun and Bonghwa-gun in Gyeongbuk province, Korea, between August and September 2023 isolated f ive fungal strains from fruits with sooty blotch and flyspeck (SBFS) disease. The strains were designated as KNUF-23-CS02, KNUF-23-CS-06, KNUF-23-CS12, KNUF-23-BH01, and KNUF-23BH03. When grown on potato dextrose agar and 2% water agar, the cultural characteristics of the strains were similar to those previously reported characteristics of Peltaster fructicola Pf001. The strains produced monoblastic, hyaline conidiogenous cells; the conidia were hyaline, unicellular, cylindrical to ovoidal, and 3.5-7×1.7-3.9 and 4.0-6.6×1.8-3.2 μm in size on synthetic nutrient-poor agar or water agars, respectively. Secondary conidia production by microcyclic conidiation and budding was observed. The KNUF-23-BH03 strain was shown to cause SBFS symptoms similar to those observed on the apples in the pathogenicity test. Molecular phylogenetic analyses were conducted based on the isolated species sequences of the internal transcribed spacer region, nuclear large ribosomal DNA subunit, and mitochondrial small ribosomal RNA subunit gene. The five strains were clustered with Peltaster fructicola Pf001. Based on the cultural and morphological characteristics and phylogenetic analysis, the five strains were identified as Peltaster fructicola, which has not been previously reported in Korea.