Unreported Post-harvest Disease of Apples Caused by Plenodomus collinsoniae in Korea

Kallol Das1   Yeong-Hwan Kim1   Jingi Yoo2   Leonid N. Ten1   Sang-Jae Kang1   In-Kyu Kang3   Seung-Yeol Lee1,4,*   Hee-Young Jung1,4   

1School of Applied Biosciences, Kyungpook National University, Daegu 41566, Korea
2Tree Fruit Research and Extension Center, Washington State University, Wenatchee 98801, USA
3Department of Horticultural Science, Kyungpook National University, Daegu 41566, Korea
4Institute of Plant Medicine, Kyungpook National University, Daegu 41566, Korea


This study was conducted to isolate and identify the fungal pathogen caused unreported post-harvest disease on apples (cv. Fuji) fruit in Korea. The disease symptoms on apples appeared as irregular, light to dark brown, slightly sunken spots. The three fungal strains were isolated from infected tissues of apple fruits and their cultural and morphological characteristics were completely consistent with those of Plenodomus collinsoniae. The phylogenetic analysis using the internal transcribed spacer (ITS) regions, beta-tubulin (TUB), and the second largest subunit of RNA polymerase II (RPB2) sequences revealed the closest relationship of the isolates with Plenodomus collinsoniae at the species level. The pathogenicity test showed the same dark brown spots on Fuji apple cultivar. Therefore, P. collinsoniae is a newly reported fungal agent causing post-harvest disease on apples in Korea.

Figures & Tables

Fig. 1.Disease symptoms, cultural and morphological characteristics, and pathogenicity test on apples (cv. Fuji) with inoculation using colony agar blocks of KNU-20-A1. (A-D): Primary symptoms; (E, F): Colony of strain KNU-20-A1 on potato dextrose agar (PDA) after 10 days; (G,H): Colony of strain KNU-20-A1 on oatmeal agar (OA) after 10 days; (I, J): Inoculation after 14 days; (K, L): Enlarged picture; M: After 30 days, pycnidia-like structures on PNA (pine needle agar); (N): After 30 days, pycnidia-like structures on OA agar; (O, P): Hyphal structures of KNU-20-A1 (scale bars: M, N=500 μm; O, P=10 μm).