title: First Report of Potato Stem-End Rot Caused by Fusarium oxysporum in Korea.
abstract: In this study, we identified the causative agent of stem-end rot in potatoes that were grown in Gangwon alpine areas of Korea in 2013. The disease symptoms included appearance of slightly sunken circular lesion with corky rot on the potato surface at the stem-end portion. The fungal species isolated from the infected potatoes were grown on potato dextrose agar and produced white aerial mycelia with dark violet pigments. The conidiophores were branched and monophialidic. The microconidia had ellipsoidal to cylindrical shapes and ranged from 2.6~11.4 × 1.9~3.5 µm in size. The macroconidia ranged from 12.7~24.7 × 2.7~3.6 µm in size and had slightly curved or fusiform shape with 2 to 5 septate. Chlamydospores ranged from 6.1~8.1 × 5.7~8.3 µm in size and were present singly or in pairs. The causal agent of potato stem-end rot was identified as Fusarium oxysporum by morphological characterization and by sequencing the internal transcribed spacer (ITS1 and ITS4) regions of rRNA. Artificial inoculation of the pathogen resulted in development of disease symptoms and the re-isolated pathogen showed characteristics of F. oxysporum. To the best of our knowledge, this is the first study to report that potato stem-end rot is caused by F. oxysporum in Korea.
authors: Department of Plant Science, Gangneung-Wonju National University, Gangneung 210-702, Korea.
authors: Md
authors: M
authors: Aktaruzzaman
authors: Department of Plant Science, Gangneung-Wonju National University, Gangneung 210-702, Korea.
authors: Sheng-Jun
authors: SJ
authors: Xu
authors: Department of Plant Science, Gangneung-Wonju National University, Gangneung 210-702, Korea.
authors: Joon-Young
authors: JY
authors: Kim
authors: Department of Plant Science, Gangneung-Wonju National University, Gangneung 210-702, Korea.
authors: Jae-Hyoun
authors: JH
authors: Woo
authors: Daegwallyong Horticultural Cooperative, Pyungchang 232-950, Korea.
authors: Young-Il
authors: YI
authors: Hahm
authors: Department of Plant Science, Gangneung-Wonju National University, Gangneung 210-702, Korea.
authors: Byung-Sup
authors: BS
authors: Kim
keywords: Fusarium oxysporum; Pathogenicity; Solanum tubersum; Stem-end rot of potato