Foot Rot of Bok Choy and Kale Caused by Rhizoctonia solani AG-2-1 in Korea

Wan-Gyu Kim¹ Gyo-Bin Lee¹ Hong-Sik Shim¹ Weon-Dae Cho^1,*

¹Global Agro-Consulting Corporation, Suwon 16614, Korea

Abstract

Foot rot symptoms were occasionally observed on young bok choy (Brassica rapa subsp. chinensis) and kale (B. oleracea var. viridis) plants grown in vinyl greenhouses located in Icheon and Yangpyeong, Gyeonggi Province, Korea. These observations were made during disease surveys in April 2020. The incidence of diseased plants in the vinyl greenhouses investigated was 0.5-1.0% in bok choy and 0.5-5.0% in kale. Five isolates of Rhizoctonia sp. were obtained from diseased roots of bok choy and three isolates of Rhizoctonia sp. were taken from diseased stems of kale. All the Rhizoctonia sp. isolates were identified as Rhizoctonia solani AG-2-1 based on the morphological characteristics and anastomosis test. Three isolates each of R. solani AG-2-1 from bok choy and kale were tested for pathogenicity in their host plants by artificial inoculation. The tested isolates induced foot rot symptoms on the inoculated bok choy and kale plants. The symptoms on the bok choy and kale, induced by the artificial inoculation, were similar to those observed on plants from the vinyl greenhouses that were investigated. This is the first report of R. solani AG-2-1 causing foot rot in bok choy and kale in Korea.

Figures & Tables

Fig. 1. Foot rot symptoms in bok choy and kale. A and B, symptoms on young plants of bok choy and kale, respectively observed in the vinyl greenhouses investigated; C and D, symptoms on plants of bok choy and kale, respectively induced by artificial inoculation tests with AG-2-1 isolates; E and F, non-inoculated plants of bok choy and kale (control), respectively.