Races and Dominant Population of Chinese Cabbage Clubroot Pathogen, Plasmodiophora brassicae in Korea

Jang, Se Jeong; Heo, Seung Hwan; Jang, Chang Soon; Kang, Sung Woo; Lim, Yong Ryo; Kim, Hong Gi

Research in Plant Disease 2007;13(1):45-49.
Published online April 30, 2007.

국내 배추 뿌리혹병균, Plasmodiophora brassicae의 race와 그 우점 양상

장세정, 허승환, 장창순, 강성우, 임용표, 김홍기

Races and Dominant Population of Chinese Cabbage Clubroot Pathogen, Plasmodiophora brassicae in Korea

Se Jeong Jang, Seung Hwan Heo, Chang Soon Jang, Sung Woo Kang, Yong Ryo Lim, Hong Gi Kim

Abstract

Single spores were isolated from infected roots of Chinese cabbage with a typical clubroot symptom, collected from different Chinese cabbage cultivation areas in Korea. When the single spore isolates were inoculated on Chinese cabbage, radish, turnip, kale, leaf mustard and Williams`` differential varieties, among 321 roots harvested two weeks after inoculation, a visual symptom was observed on only one root and light/uncommon symptoms were done on 70 roots. These 71 individuals were homogenized and used as inocula. These inocula caused generally higher pathogenicity than that of single spore. Finally 15 isolates, with enough growth for conducting further experiment, were selected. These 15 individuals were grouped four, seven, two and two into race 1, race 4, race 9 and race 11, respectively, using Williams`` differential set. It was confirmed that race 4 were dominantly present in Korea. These 15 had been obtained from roots of Chinese cabbages, radishes and turnips inoculated with single resting spores and had shown pathogenicity to Laurentian and Wilhelmsburger belong to Rutabaga in Williams`` differential variety set. Therefore, we assume that such characteristic pathotypes including race 4, especially, of P. brassicae showing strong pathogenicity to Chinese cabbage, radish and turnip may be dominant in Korea.

Key Words: Chinese cabbage, Clubroot, Plasmodiophora brassicae, Race, Single spore isolate, SSI