First Report of Root Rot of Dendropanax trifidus Caused by Fusarium oxysporum in Korea

Hyerin Ma^1,2 Sungyu Choi³ Hyunkyu Sang^3,* Hyun-Jun Kim^1,*

¹Department of Biomedicine and Biotechnology, Paichai University, Daejeon 35345, Korea
²Department of Biomedicine and Biotechnology, Paichai University, Daejeon 35345, Korea
³Department of Biomedicine and Biotechnology, Paichai University, Daejeon 35345, Korea

Abstract

Dendropanax trifidus belonging to the family Araliaceae, is a warm-temperate evergreen tree distributed in Jeju Island, Bogil Island, Geomun Island, Geoje Island, Wando, and Haenam in Korea. In June 2021, a root rot disease in which branches of Dendropanax trifidus seedlings turned brown and shrunk was discovered at the seedling cultivation facility in Naju-si, Republic of Korea. To identify the root rot fungus, three strains were isolated from the diseased tissues of seedlings and their mycological characteristics were investigated on potato dextrose agar. In addition, a molecular phylogenetic analysis was performed using sequences of the internal transcribed spacer (ITS) region and translation elongation factor 1-α (EF1-α) gene. The fungus was identified as Fusarium oxysporum. For pathogenicity test, the roots of seedlings were immersed in the conidia suspension of the strains and planted. After 20 days inoculation, root rot and browning symptoms were confirmed in the inoculated plants. This is the first report of F. oxysporum on D. trifidus in Korea.

Figures & Tables

Fig. 1.Symptoms and mycological characteristics of Fusarium root rot on seedling of caused by . (A) seedlings exhibiting low germination rate and root rot symptoms (right). (B) Brown encrosis appearing on stems and roots. (C ) Top and bottom view of cultured on potato dextrose agar after 7 days. (D) Microconidia. (E) Macroconidia. Scale bars=20 μm. (F) Symptoms on stems and roots artificially inoculated with F. oxysporum. (G) Untreated control.