• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2002년도 총회 및 추계학술발표회
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• pp.70.2-70
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• 2002

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.33-33
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• 2015

Clubroot disease is the major threat to the production of Chinese cabbage (Brassica rapa L.) in Japan. Although the breeding of the clubtoot resistant (CR) cultivars is one of the most efficient ways to control this disease, the CR cultivars do not always have effects due to the breakdown of resistance. Therefore, it is necessary to develop the breeding strategy to accumulate multiple CR genes in a single cultivar effectively. We have identified two incomplete dominant CR loci, Crr1 and Crr2, which are originated from the European CR turnip Siloga. To investigate the effectiveness of marker-assisted selection (MAS) for CR breeding, the inbred line with Crr1 and Crr2 was crossed with parental lines of the existing CR $F_1$ cultivar of Chinese cabbage, followed by 5 times of MAS and backcrossing. The $F_1$ derived from a cross between the resulting parental lines improved the clubroot resistance as expected and had the same morphological characters as the original $F_1$ cultivar. We have shown that the Crr1 locus comprised two loci: Crr1a, which by itself conferred resistance to the mild isolate; and Crr1b, which had a minor effect, but was not required for Crr1a-mediated resistance. Further genetic analysis suggested that Crr1b was necessary to acquire resistance to the more virulent isolate in combination with Crr2. Molecular characterization of Crr1a encoding TIR-NB-LRR class of R protein revealed that there were at least 4 alleles in Japanese CR cultivars of Chinese cabbage. PCR analysis with Crr1a-specific markers demonstrated that the functional alleles were predicted to be present in European CR turnips, Debra and 77b besides Siloga, whereas rarely in Japanese CR cultivars, indicating that Crr1a is an useful source to improve the resistance of Chinese cabbage cultivars.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.27-27
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• 2015

Clubroot (Plasmodiophora brassicae) is a serious agricultural problem affecting Brassica crop production worldwide. It also infects the model plant Arabidopsis thaliana. During infection, this biotrophic pathogen manipulates the development and metabolism of its host leading to the development of galls in the root and hypocotyl. In turn, its own development is strongly influenced by the host. The aim of this study is to investigate the metabolism of clubroot-infected plants using a combination of transcriptomic and metabolomic approaches. We have used direct injection mass spectrometry to obtain a metabolic fingerprint of when changes in the metabolome occur and linked this with changes in host and pathogen gene expression. We have identified alterations in carbohydrate metabolism that occur during P. brassicae infection of A. thaliana plants. Transcriptomic analysis showed that host genes associated with sugar transport and metabolism were induced during gall formation and that the pathogen also expresses genes associated with these processes. We have examined the impact of inactivating host sucrose synthase, cytosolic invertase and sugar permeases on gall formation, identifying host genes that are required for gall formation. We have also explored how sugar status is changed in root tissue, developing and mature leaf during infection of wild type and mutant plants.

• 식물병연구
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• 제20권1호
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• pp.21-24
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• 2014

Plasmodiophora brassicae는 십자화과 작물에 뿌리혹병을 일으키는 주요 병원균이다. 본 연구에서는 뿌리혹병균의 신속 정확한 검출을 위해서 뿌리혹병균에 대한 새로운 종 특이적 프라이머를 개발하고자 하였다. 새롭게 개발된 프라이머들은 10종의 주요 토양병원균을 비롯하여 기주인 배추 DNA와는 반응하지 않고 P. brassicae와만 반응하는 특이성을 갖고 있었다. 그 가운데 Primer ITS1-1/1-2는 민감도 검정 결과, 10 spores/ml의 DNA까지 검출이 가능함으로써, first round PCR용임에도 불구하고 이전의 검출법 보다 감도가 높고 정확한 결과를 얻었다. Quantitative real-time PCR로 분석할 경우에는 더 적은 수의 포자까지 안정적으로 검출해 낼 수 있어 새로운 P. brassicae 종 특이적 프라이머로서의 유용성을 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제23권3호
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• pp.313-321
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• 2013

Bacillus subtilis XF-1, a strain with demonstrated ability to control clubroot disease caused by Plasmodiophora brassicae, was studied to elucidate its mechanism of antifungal activity against P. brassicae. Fengycin-type cyclopeptides (FTCPs), a well-known class of compounds with strong fungitoxic activity, were purified by acid precipitation, methanol extraction, and chromatographic separation. Eight homologs of fengycin, seven homologs of dehydroxyfengycin, and six unknown FTCPs were characterized with LC/ESI-MS, LC/ESI-MS/MS, and NMR. FTCPs (250 ${\mu}g/ml$) were used to treat the resting spores of P. brassicae ($10^7/ml$) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm ($A_{260}$) and at 280 nm ($A_{280}$) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be cleaved by the FTCPs of B. subtilis XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol.

• 식물병연구
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• 제18권2호
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• pp.123-128
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• 2012

We investigated the resistance of 50 commercial Chinese cabbage cultivars against clubroot disease caused by Plasmodiophora brassicae in the three difference fields, Suwon, Hwacheon, and Pyeongchang. Wilting symptom on Chinese cabbage was first observed at 15 days after transplanting in Pyeongchang and Hwacheon, while disease symptoms appeared later in Suwon after the rainy season. Among 50 cultivars, eight cultivars, SC26, SC29, SC30, SC31, SC34, SC46, SC47 and SC50 showed highly susceptible symptoms like wilting and heavy root galls in all three fields. Meanwhile, seven cultivars such as SC05, SC06, SC07, SC09, SC11, SC17, and SC36 showed moderate resistance with delayed wilting and few root galls. Only two cultivars, Chuwol (CB22) and Gohyangssam (CB23) were highly resistant to clubroot disease until the harvest season in all of the three fields. These two commercial cultivars may be considered as candidate cultivars for cultivation of organic Chinese cabbage in Suwon, Hwacheon, and Pyeongchang.

• 식물병연구
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• 제25권1호
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• pp.33-37
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• 2019

2016년부터 2018년까지 제주도내 농가포장에서 재배되고 있는 콜라비에 뿌리혹병 지속적으로 발생(최고발병률 27.2%)했다. 초기 감염은 뿌리털 부분이 정상주 뿌리털에 비해 비대했으며, 병이 진전되면서 뿌리 중심부에 혹이 형성되고, 잎이 시들고 끝이 누렇게 변했다. P. brassicae 휴면포자 현탁액을 이용한 병원성 검정결과 접종 50일 후에 병원성을 나타냈다. 병원균은 콜라비 세포조직 안에 빈 곳 없이 무수히 많은 휴면포자를 형성하며, 휴면포자는 단세포로 무색, 원형 또는 타원형, 크기는 직경 $3-5{\mu}m$이다. 콜라비 뿌리혹병원균의 ITS rDNA 염기서열 분석, 계통수 작성 결과 P. brassicae로 동정했다. 따라서 균학적 특징, 병원성 검정, ITS rDNA 염기서열 비교분석 등의 결과를 바탕으로 이 병은 우리나라에서 지금까지 보고되지 않은 'Plasmodiophora brassicae에 의한 콜라비 뿌리혹병'으로 명명하고자 한다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.28-28
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• 2015

Clubroot disease caused by Plasmodiophora brassicae induces severe losses of cruciferous vegetables worldwide. To control clubroot of Chinese cabbage, many CR (clubroot resistance) F1 hybrid cultivars have been bred and released in Korea, China and Japan. In this study, we determined the race of P. brassicae 12 field isolates, which collected from 10 regions in Korea, using Williams' differential varieties including two cabbage ('Jersey Queen', 'Badger Shipper') and two rutabaga ('Laurentian', 'Whilhelmsburger'). By Williams' differential varieties, 12 clubroot pathogens were assigned into one (GN2), two (HS and YC), two (HN1 and HN2), three (DJ, KS and SS) and four (GS, GN1, JS and PC) isolates for races 1, 2, 4, 5 and 9, respectively. In addition, the degree of resistance of 45 CR cultivars that were from Korea, China and Japan was tested with the 12 isolates. The 45 CR cultivars of Chinese cabbage were differentiated into three genotypes according to their resistance responses. Even though the 12 P. brassicae isolates were same race by Williams' differential varieties, three CR genotypes showed different resistance response to the isolates. These results indicate that races of P. brassicae by Williams' differentials were not related with resistance of CR cultivars, and three CR genotypes represented qualitative resistance to the P. brassicae isolates. CR genotype I including 'CR-Cheongrok' showed resistance to GN1, GN2, JS, GS, HS, DJ and KS isolates and susceptibility to YC, PC, HN1, HN2 and SS isolates. And CR genotype II such as 'Hangkunjongbyungdaebaekchae' was resistant to GN1, GN2, JS, GS, HS, YC, PC and HN1 and susceptible to DJ, KS, SS and HN2. CR genotype III including 'Chunhajangkun' and 'Akimeki' represented resistance to 10 isolates except for SS and HN2 isolates. Based on these results, we selected 'CR-Cheongrok', 'Hangkunjongbyungdaebaekchae', and 'Chunhajangkun' as a representative cultivar of three CR genotypes and 'Norangkimjang' as a susceptible cultivar. Furthermore, we investigated the resistance of 15 lines of Chinese cabbage, which were provided by seed companies, to 11 isolates except for HN1 of P. brassicae. The results showed that three lines were susceptible to all the tested isolates, whereas five, four, and three lines represented the similar responses corresponding to the CR genotypes I, II, and III, respectively; there is no line of Chinese cabbage showing different resistance patterns compared to three CR genotypes. In particular, line 'SS001' showing resistance responses of CR genotype II was a parent of 'Saerona' that have been commercialized as a CR $F_1$ cultivar of Chinese cabbage. Together, we divided 12 isolates of P. brassicae into 4 races, designated by wild type, mutant type 1, mutant type 2, and mutant type 3. Wild type including GN1, GN2, JS, GS, and HS isolates of P. brassicae was not able to infect all the cultivars of three CR genotypes, whereas, mutant type 3 such as SS and HN2 isolates developed severe clubroot disease on all the CR genotype cultivars. To mutant type 1 including DJ and KS isolates, CR genotypes I, II and III were resistant, susceptible and resistant, respectively. In contrast, to mutant type 2 including YC, PS, and HN1 isolates, CR genotypes I, II and III showed susceptibility, resistance and resistance, respectively. Taken together, our results provide the extended knowledge of classification of P. brassicae races, which is useful information for the breeding of resistant crops, with a suggestion that 'Norangkimjang', 'CR-Cheongrok', 'Saerona' and 'Chunhajangkun' cultivars of Chinese cabbage could be used as new race differentials of P. brassicae for clubroot disease assay.

• 식물병연구
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• 제20권4호
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• pp.235-244
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• 2014

Brassica olerace의 주요 병해인 뿌리혹병과 시들음병에 대한 저항성 유전자원을 발굴하기 위하여, 농업유전자원정보센터로부터 제공받은 양배추(B. oleracea var capitata) 유전자원 60개와 브로콜리(B. oleracea var italica) 유전자원 6개의 뿌리혹병과 시들음병에 대한 저항성을 검정하였다. 유전자원의 뿌리혹병에 대한 저항성 검정을 위해서, 분양 받은 유전자원들의 유묘에 뿌리혹병균 Plasmodiophora brassicae의 포자현탁액을 접종하였다. 실험한 유전자원 중 양배추 유전자원 4개는 중도저항성을 보였으며, 이들 중 양배추 유전자원 'K166220'는 가장 높은 저항성을 나타냈다. 나머지 유전자원들은 감수성을 보였다. 한편, 유전자원의 시들음병에 대한 저항성을 검정하기 위하여 분양 받은 유전자원 유묘의 뿌리를 Fusarium oxysporum f. sp. conglutinans 포자 현탁액에 침지하여 접종하였다. 실험한 유전자원 중 양배추 유전자원 17개와 브로콜리 유전자원 5개는 저항성, 양배추 유전자원 16개는 중도저항성 그리고 나머지 유전자원은 감수성이었다. 특히 양배추 유전자원 3종('IT227115', 'K161791', 'K173350')과 브로콜리 유전자원 2종('IT227100', 'IT227099')은 시들음병에 대하여 높은 저항성을 보였다. 본 연구에서 확인된 뿌리혹병과 시들음병 저항성 유전자원들은 뿌리혹병과 시들음병 저항성 육종에 이용될 수 있을 것이다.

• 식물병연구
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• 제15권3호
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• pp.242-247
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• 2009

고랭지의 배추 뿌리혹병 방제에 적합한 윤작작물을 선발하고자 2000년 감자, 옥수수, 콩, 양파, 곰취 등을 뿌리 혹병 이병포장에 재배하면서 뿌리혹병 발생에 미치는 영향을 조사하였다. 윤작작물들간의 경제성 비교에서는 감자와 양파 재배가 배추 연작에 비해 각각 약 16.9와 14.9배 더 높은 소득을 나타내었다. 윤작작물 재배 후의 토양 내 휴면포자 밀도는 모든 작물에서 $0.3{\sim}1.2{\times}10^3/g$ 토양이었고 배추 연작재배에서는 $89.3{\times}10^3/g$ 토양이었다. 2001년 동일 포장에 배추를 재배한 결과 뿌리혹병 발병도는 배추 연작재배의 77.8%에 비해 양파, 콩, 감자, 옥수수, 곰취 재배에서 각각 4.9, 20.2, 24.4, 25.1, 27.8%로 낮게 나타났다. 윤작작물의 재배기간에 따른 뿌리혹병 방제 효과를 양파, 감자, 콩 등의 작물로 2002년부터 2005년까지 시험하였다. 윤작작물 재배 후의 휴면포자 밀도는 모든 작물에서 2년째 재배까지 감소하였고 3년째 재배에서는 낮은 밀도가 유지되는 반면 배추 연작재배에서는 3년 동안 2.6에서 23.6배까지 증가하였다. 3년간의 윤작작물 재배를 통한 배추의 뿌리혹병 발병도는 감자 재배가 92%에서 4.4%, 콩 재배가 72%에서 10.4%, 양파 재배가72%에서 12.2%를 보이며 크게 감소한 반면 배추 연작재배에서는 100%를 유지하였다. 배추의 수량은 윤작기간이 길어질수록 증가되었으나 연작재배에서는 감소하였으며 3년째에는 연작재배의 배추 포기당 무게 95 g에 비해 감자, 콩, 양파 재배에서는 각각 2,205, 2,493, 2,476 g의 상품성 있는 배추가 생산되었다.