Diversity and Pathogenic Characteristics of Fusarium Species isolated from Wilted Soybeans in Korea

Hyo-Won Choi1,*   Seungnoh Kim2   Sung Kee Hong1   

1Crop Protection Division, National Institute of Agricultural Sciences, Wanju 55365, Korea
2Taean Agricultural Technology Center, Taean 32144, Korea


Wilted soybean plants were collected from soybeans cultivation fields in Korea from 2014 to 2016. Fusarium spp., Colletotrichum spp., Rhizoctonia spp., Macrophomina sp., Phytophthora spp., and Calonectria ilicicola were obtained from the infected samples. Out of these, Fusarium spp. were the dominant species (79.1%). In total, 53 isolates were identified as F. solani species complex, F. oxysporum species complex, F. graminearum species complex, and F. fujikuroi species complex based on mycological characteristics. Sequence typing analysis was conducted using translation elongation factor 1 alpha (TEF) to confirm the identification of isolates. All isolates were identified as F. solani, F. oxysporum, F. commune, F. asiaticum, and F. fujikuroi based on phylogenetic analysis of TEF sequences. Pathogenicity of 44 isolates was tested on three cultivars of soybean using the root dip inoculation method. Out of 5 Fusarium species, only F. asiaticum could not cause the symptoms or be weak. Ten isolates were selected based on pathogenic characters and species identification to investigate the host range and screen soybean cultivars for resistance. Fusarium solani, F. oxysporum, and F. commune were aggressive only to soybean, and F. fujikuroi was aggressive to kidney bean, yellow cowpea, black cowpea, adzuki bean as well as soybean. All 13 Korean soybean cultivars were susceptible to F. commune and F. fujikuroi. Out of 13 cultivars, cv. Janggi, cv. Poongsannamul, and cv. Socheongja were resistant to Fusarium wilt, while cv. Hwanggeumol and Chamol were susceptible to Fusarium wilt.

Figures & Tables

Fig. 1. Disease index of wilt in legume and maize plants. 0, no symptom; 1, necrosis of less than 20% of root tissue and discoloration of the vascular; 2, 21-50% necrosis of root tissue and discoloration of the vascular; 3, more than 51% necrosis of root tissue and discoloration/ necrosis of the vascular; 4, complete necrosis of root tissue and plants death.