First Report of Pythium Leak of Potato (Solanum tuberosum) Caused by Pythium aphanidermatum in Korea

First Report of Pythium Leak of Potato (Solanum tuberosum) Caused by Pythium aphanidermatum in Korea

Yu Jin Kim1, Sang Hoon Lee2, Eui-Hwan Chung1, and Ki Deok Kim1*

1Department of Plant Biotechnology, Korea University, Seoul, Korea

2Division of Biotechnology, Korea University, Seoul, Korea

*Email: kidkim@korea.ac.kr

Potato (Solanum tubersum) has been cultivated as one of the most important food crops in Korea. The potato tubers grown in 2021 and 2022 from two different areas (Hongsung, Chungnam, Korea and Chunchun, Kangwon, Korea) were shown to be watery and dark black rotten symptoms with pink tinges. In this study, the causal agent was isolated and identified as Pythium aphanidermatum by phylogenetic analysis using neighbor-joining and maximum-likelihood methods with internal transcribed spacer (ITS) and cytochrome oxidase subunit II (coxII) genes. Four isolates of the causal agent from two different regions were characterized their macro- and micro-morphologies and further tested their pathogenicity against potatoes. As a result, we observed that the morphological characteristics of the isolates from the diseased potato tubers were similar with the reference strains (KACC40156 and KACC48066) of P. aphanidermatum, and all the tested isolates proven pathogenic on potato tubers. Therefore, we reported that P. aphanidermatum is the causal agent of Pythium leak on potato and this is the first report of the disease on potato in Korea.