title: Pathotype Classification ofPlasmodiophora brassicaeIsolates Using Clubroot-Resistant Cultivars of Chinese Cabbage.
abstract: Clubroot disease caused byPlasmodiophora brassicaeis one of the most serious diseases inBrassicacrops worldwide. In this study, the pathotypes of 12 KoreanP. brassicaefield isolates were determined using various Chinese cabbage including 22 commercial cultivars from Korea, China, and Japan, and 15 inbred lines. AllP. brassicaeisolates exhibited the typical clubroot disease on non-clubroot resistant cultivar, indicating that the isolates were highly pathogenic. According to the reactions on the Williams' hosts, the 12 field isolates were initially classified into five races. However, when these isolates were inoculated onto clubroot-resistant (CR) cultivars of Chinese cabbage, several isolates led to different disease responses even though the isolates have been assigned to the same race by the Williams' host responses. Based on the pathogenicity results, the 12 field isolates were reclassified into four different groups: pathotype 1 (GN1, GN2, GS, JS, and HS), 2 (DJ and KS), 3 (HN1, PC, and YC), and 4 (HN2 and SS). In addition, the CR cultivars from Korea, China, and Japan exhibited distinguishable disease responses to theP. brassicaeisolates, suggesting that the 22 cultivars used in this study, including the non-CR cultivars, are classified into four different host groups based on their disease resistance. Combining these findings, the four differential hosts of Chinese cabbage and four pathotype groups ofP. brassicaemight provide an efficient screening system for resistant cultivars and a new foundation of breeding strategies for CR Chinese cabbage.
authors.affiliation: Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon 34113, Korea.
authors.forename: Hun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Jo
authors.affiliation: Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea.
authors.forename: Yong Ho
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea.
authors.forename: Kyoung Soo
authors.initials: KS
authors.lastname: Jang
authors.affiliation: Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon 34113, Korea.
authors.forename: Gyung Ja
authors.initials: GJ
authors.lastname: Choi
keywords: Chinese cabbage; breeding; clubroot; differential hosts; resistance