관주 접종법을 이용한 효율적인 배추 뿌리혹병 저항성 검정법 |
조수정, 장경수, 최용호, 김진철, 최경자 |
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Convenient Screening Method of Chinese Cabbage for Resistance to Plasmodiophora brassicae Using Soil-Drenching Inoculation |
Su Jung Jo, Kyoung Soo Jang, Yong Ho Choi, Jin Cheol Kim, Gyung Ja Choi |
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Abstract |
Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of 4.0 × 108 spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at 20oC for 3 days, and then cultivated in a greenhouse (25 ± 5oC) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease. |
Key Words:
Breeding, Clubroot, Crucifer crops, Cultivar, Resistant |
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