Isolation of Fungal and Bacterial Pathogens As a Causal Agent of Root Rot of Cnidii Rhizoma

Isolation of fungal and bacterial pathogens as a causal agent of root rot of Cnidii Rhizoma

Hee Sang Yun1, Hyeong Ho Park1, Chung Ryul Jung2,*, Hyong Woo Choi1,*

1Department of Plant Medicals, College of Life Sciences and Biotechnology, Andong National University, Andong, Republic of Korea

2Forest Entomology and Pathology, National Institute of Forest Science, Seoul, Republic of Korea

*Email: hwchoi@anu.ac.kr

Cnidii Rhizoma (Cnidium officinale Makino), belongs to Umbelliferae family, is a perennial plant native to China and it is also distributed in Korea and Japan. The root was used as an oriental medicine to improve blood circulation and as a pain reliever. It also treating headaches, abdominal pain, paralysis due to cold spells, and dystocia. In July 2023, the root rot of the Cnidii Rhizoma was observed in Yeongyang, Gyeongsangbuk Province, Korea, (36.687282, 129.083025). Brown necrotic symptoms from the center or edge of the root were observed. The symptomatic roots were brought to the laboratory, cut into small pieces, and surface sterilized. The tissues were plated on Potato Dextrose Agar (PDA) medium, and cultured at 28°C for 7 days. Colonies were isolated and cultured for pure isolation on freshly prepared PDA plates. In total 154 fungi and bacteria were isolated from the lesions. For the pathogenicity test, sliced healthy roots were inoculated with the fungal and bacterial isolates. After incubating the roots at 28 ° C for 7 days, rot symptoms were observed. Among them, 11 fungal and 15 bacterial isolates successfully induced root rot symptoms. No symptoms were observed in the control group. The isolated fungal and bacterial pathogens are planned to be identified morphologically and molecularly.