Characterization of Fusarium solani Causing Fusarium Root Rot of Lisianthus in Korea

Hyo-Won  Choi1,*   Sung Kee  Hong2   Young Kee  Lee1   Jeomsoon  Kim1   Jae Guem  Lee1   Hyo Won  Kim1   Eun Hye  Kang1   Eun Hyeong  Lee1   

1Crop Protection Division, National Institute of Agricultural Sciences
2Microbial Safety Team, National Institute of Agricultural Sciences

Abstract

Lisianthus (Eustoma grandiflorum) is a flowering ornamental plant used widely in Korea. In 2015, wilting, damping-off, stunting, and root rot symptoms were observed in lisianthus plants of Yeoju and Gimhae, Korea. Affected seedlings appeared yellow and showed poor development of root systems in the field and in nursery boxes. Furthermore, affected plants were yellow, stunted, and died at approximately 2–3 months after transplanting. Fusarium species were consistently isolated from the basal stems of diseased plants. Nine isolates were identified as Fusarium solani based on morphological characteristics. Macroconidia of isolates were relatively wide, straight-to-slightly curved, and microconidia formed in false heads on long monophialides. Abundant chlamydospores were produced at the middle or tips of hyphae. To confirm this identification, a molecular analysis of the translation elongation factor 1 alpha (TEF) and RNA polymerase II subunit (RPB2) genes was conducted. The sequences of TEF and RPB2 showed 99.2–99.9% and 98.0–98.1% similarity, respectively, to those of reference F. solani strains in NCBI GenBank. Pathogenicity was tested using root dipping inoculation of healthy lisianthus seedlings. Symptoms were observed within 7 days of inoculation only in inoculated plants. This is the first report of F. solani causing Fusarium root rot on lisianthus in Korea.

Acknowledgements

This study was supported by a grant (Project No. PJ010004) from Rural Development Administration, Republic of Korea.

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