English
First Report of Peach Canker Caused by Diaporthe eres in Korea
Yu Bi Kim1, Cheong Woon Kim1, Gyoung Hee Kim1,2*
1Department of Agricultural Life Science, Sunchon National University, Suncheon, Republic of Korea
2Department of Plant Medicine, Sunchon National University, Suncheon, Republic of Korea
*Email: ghkim@scnu.ac.kr
Canker diseases caused by Diaporthe species are important diseases of woody plants, including peach, leading to twig dieback and decline. In February 2025, canker symptoms were observed on peach (Prunus persica L.) trees in a commercial orchard in Woldeung, Jeonnam Province, Korea. Initial symptoms included browning of the bark, followed by the development of sunken lesions accompanied by cracking and necrosis of cortical tissues. As the disease progressed, elongated and sunken cankers formed on branches and trunks, frequently expanding and coalescing. Infected tissues exhibited internal brown discoloration of vascular tissues, and gummosis was occasionally observed on lesion surfaces. Severe infections resulted in extensive stem cankers and dieback of affected branches. Fungal isolates obtained from symptomatic tissues were cultured on potato dextrose agar (PDA), producing cottony colonies with gray aerial mycelia and pale yellow conidial masses. Alpha conidia were hyaline, smooth, fusiform to cylindrical, measuring 6.2–9.7 × 3.0–4.7 μm (n = 100), whereas beta conidia were hyaline, smooth, curved, with a subtruncate base and tapering apex, measuring 21.0–29.0 × 1.0–1.6 μm (n = 30). These characteristics were consistent with Diaporthe eres. Phylogenetic analyses based on ITS, TUB2, TEF1-α, and CAL sequences confirmed the isolate as D. eres. Pathogenicity was verified by inoculating healthy peach stems with mycelial plugs. Typical canker symptoms developed within 14 days after inoculation, and the pathogen was consistently re-isolated from inoculated tissues, fulfilling Koch’s postulates. This is the first report of peach canker caused by D. eres in Korea.
