Damping-off of Deltoid Synurus Caused by Rhizoctonia solani AG AG-1 (IB)

Wan-Gyu Kim^1,* Gyo-Bin Lee¹ Hong-Sik Shim¹ Weon-Dae Cho¹

¹Global Agro-Consulting Corporation, Suwon 16614, Korea

Abstract

Damping-off symptoms were frequently observed in young deltoid synurus (Synurus deltoides) plants grown in a farmer's vinyl greenhouse located in Hwacheon, Gangwon Province, Korea, during a disease survey in July 2019. The incidence of diseased plants in the vinyl greenhouse investigated was 5-30%. Five isolates of Rhizoctonia sp. were obtained from the diseased plants and identified as Rhizoctonia solani AG AG-1 (IB), based on morphological and cultural characteristics and anastomosis test results. Three isolates of R. solani AG-1 (IB) were tested for pathogenicity on deltoid synurus using artificial inoculation. All the tested isolates induced damping-off symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the farmer's vinyl greenhouse. To our best knowledge, this is the first report of R. solani AG-1 (IB) causing damping-off in deltoid synurus.

Figures & Tables

Fig. 1. Damping-off symptoms of deltoid synurus plants. A and B: Symptoms observed in the vinyl greenhouse investigated. C: Symptoms induced by artificial inoculation tests with AG-1 (IB) isolates. D: Non-inoculated plants (control).