• 한국육종학회지
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• 제43권4호
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• pp.241-251
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• 2011

Bacterial blight(BB) caused by Xanthomonas oryzae pv. oryzae(Xoo) is one of the most economically destructive bacterial diseases of rice in worldwide. Utilization of resistant cultivars carrying resistant gene(s) is relatively an effect method to control this disease. About 34 resistant genes for BB resistance have been identified in many countries. Among them, Xa1 and Xa3 genes against bacterial blight have been incorporated into improved korean japonica rice varieties. Now, Ilmi carrying Xa1 gene and severial cultivars carrying Xa3 gene are widely grown in our country. In recent year, xa5, Xa21 and Xa23 genes are using in rice breeding programs for japonica resistant cultivars to bacterial blight. Resistant cultivars incorporated with a diverse single gene and two, three, or the more major gene necessite in the future.

• 식물병과 농업
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• 제5권1호
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• pp.46-49
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• 1999

Bacterial blight occurred on the flowers, leaves, twigs and branches of apple trees (Malus domestica Borkh) in Chunchon, Kangwon-Do. Infected flowers and leaves turned brownish black, and they were fallen down or remained hanging in the trees. Under humid conditions during postblossom period, the casual bacterium spreaded along twigs and killed them. However, killing of branches was very rare. The symptoms on apple trees were very similar to symptoms of fire blight. But the causal organism isolated from the lesions was identified as Pseudomonas syringae based on physiological and chemical characteristics. This is the first described bacterium that causes apple shoot blight in Korea.

• 식물병과 농업
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• 제1권1호
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• pp.19-29
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• 1995

A microbial product composed of three antagonistic fungal isolates (Aspergillus sp., Penicillium sp. and Trichoderma sp.) and three bacterial isolates (Arthrobacter sp., Bacillus sp., and Pseudomonas sp.) was tested for the control of Pythium blight caused by Pythium sp., brown patch by Rhizoctonia solani (anastomosis group(AG) 1-1) and large patch by R. solani (AG 2-2) of turfgrasses. Cultures of the antagonistic fungi and bacteria varied in the effectiveness in reducing disease severity of Pytium blight and brown patch on bentgrass. The antagonistic fungal and bacterial isolates were mixed and cultured at 20-$25^{\circ}C$ for 3 days in a growth medium, and the diluted solution of the microbial culture was applied under the field conditions after inoculation of the above turfgrass pathogens. The treated turfgrass was incubated at 28$^{\circ}C$ in a growth chamber. In this experiment, Pythium blight was almost completely controlled and brown patch was slightly decreased by the microbial product, while no control was observed in large patch of zoysiagrass. In zoysiagrass treated with the microbial culture, thatch accumulation was notably reduced.

• 식물병연구
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• 제22권3호
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• pp.202-207
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• 2016

쌀은 세계에서 가장 중요한 작물 중의 하나이지만 충분한 비타민을 제공하지 않고, 벼 도열병과 흰잎마름병은 전 세계적으로 가장 큰 피해를 주고 있는 병해이다. 리보플라빈, 비타민 B2는 인간의 건강에 필수적인 영양소이며, 식물의 병원균에 대한 식물의 방어 활성화로 알려져 있다. 본 연구에서는 BioDoctor (Hyunnong Co., Ltd., Gokseong, Korea)라는 리보플라빈 기반 제품을 벼에 경엽살포했을 때, 주요 병해에 대한 저항성 유도 및 벼 체내에 비타민 함량이 증가되는지에 대한 가능성을 조사하였다. 온실검정에서 BioDoctor 제품 500배와 1,000배로 희석하여 경엽처리 결과 벼 도열병과 흰잎마름병에 대해 현저한 병 저항성을 유도하였다. 또한, BioDoctor를 처리한 알곡과 잎에서 통계적으로 유의한 수준으로 리보플라빈 함량이 검출되었다. 본 연구는 비타민인 리보플라빈이 함유된 BioDoctor가 벼 도열병과 흰잎마름병에 대해 병 저항성을 유도할 뿐만 아니라 쌀 곡류 내에 비타민 함량을 증가시키는 큰 잠재력을 가지고 있는 것으로 나타났다.

• 식물병연구
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• 제21권4호
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• pp.268-272
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• 2015

마늘 세균점무늬병은 국내에서 제주지역 난지형 마늘에서 Pseudomonas syringae pv. morri에 의해 발생하는 세균병해로 주요 병해 중 하나이다. 본 연구는 자연로그를 취한 이항분산에 대한 관측분산의 회귀모델인 binary power law를 이용하여 포장 내 병 발생의 공간분포 특성을 분석하였다. 회귀식의 기울기(b) 값이 1.361로 기준치인 1보다 커 세균점무늬병은 공간적으로 집중분포하고 있었다. 축차표본조사법은 평균이병주율($p_m$)의 추정과 요방제수준($p_t$) 이상 또는 이하 여부를 판단할 수 있도록 개발하였다. 본 연구결과는 기존의 조사지점수 고정 조사 방법에 비해 조사비용 면에서 더 효율적인 동시에 조사결과의 정확도를 더 높일 수 있을 것으로 판단된다.

• The Plant Pathology Journal
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• 제37권4호
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• pp.396-403
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• 2021

Fire blight disease, caused by Erwinia amylovora, could damage rosaceous plants such as apples, pears, and raspberries. In this study, we designed to understand how E. amylovora affected other bacterial communities on apple rhizosphere; twig and fruit endosphere; and leaf, and fruit episphere. Limited studies on the understanding of the microbial community of apples and changes the community structure by occurrence of the fire blight disease were conducted. As result of these experiments, the infected trees had low species richness and operational taxonomic unit diversity when compared to healthy trees. Rhizospheric bacterial communities were stable regardless of infection. But the communities in endosphere and episphere were significanlty affected by E. amylovora infection. We also found that several metabolic pathways differ significantly between infected and healthy trees. In particular, we observed differences in sugar metabolites. The finding provides that sucrose metabolites are important for colonization of E. amylovora in host tissue. Our results provide fundamental information on the microbial community structures between E. amylovora infected and uninfected trees, which will contribute to developing novel control strategies for the fire blight disease.

• The Plant Pathology Journal
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• 제26권2호
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• pp.178-184
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• 2010

Four major diseases of chili pepper including two fungal diseases, anthracnose (Colletotrichum acutatum) and Phytophthora blight (Phytophthora capsici), and two bacterial diseases, bacterial wilt (Ralstonia solanacearum) and bacterial spot (Xanthomonas campestris pv. vesicatoria), were investigated under future climate-change condition treatments in growth chambers. Treatments with elevated $CO_2$ and temperature were maintained at $720ppm{\pm}20ppm$ $CO_2$ and $30^{\circ}C{\pm}0.5^{\circ}C$, whereas ambient conditions were maintained at $420ppm{\pm}20ppm$ $CO_2$ and $25^{\circ}C{\pm}0.5^{\circ}C$. Pepper seedlings or fruits were infected with each pathogen, and then the disease progress was evaluated in the growth chambers. According to paired t-test analyses, bacterial wilt and spot diseases significantly increased by 24% (p=0.008) and 25% (p=0.016), respectively, with elevated $CO_2$ and temperature conditions. On the other hand, neither Phytophthora blight (p=0.906) nor anthracnose (p=0.125) was statistically significant. The elevated $CO_2$ and temperature accelerated the progress of bacterial wilt by two days and bacterial spot by one day compared to the ambient treatment. Temperature regime studies of the diseases without changes in $CO_2$ confirmed that the accelerated bacterial disease progress was mainly due to the increased temperature rather than the elevated $CO_2$ conditions.

• 식물병연구
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• 제19권3호
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• pp.177-182
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• 2013

Resvestrol has been known to inhibit bacterial and fungal growth in vitro, and can be accumulated in plant to concentrations necessary to inhibit microbial pathogens. Hence, stilbene synthase gene has been used to transform to synthesize resveratrol in heterologous plant species to enhance resistance against pathogens. In the present study, we investigated the antimicrobial activities of resveratrol and piceid to bacterial and fungal pathogens, which causing severe damages to rice plants. In addition, disease resistance was compared between transgenic rice varieties, Iksan 515 and Iksan 526 transformed with stlibene synthase gene and non-transgenic rice varieties, Dongjin and Nampyeong. Minimum inhibitory concentration of resveratrol for Burkolderia glumae was 437.5 ${\mu}M$, and the mycelial growth of Biplaris oryzae was slightly inhibited at concentration of 10 ${\mu}M$. However, other bacterial and fungal pathogens are not inhibited by resveratrol and piceid. The expression of the stilbene synthase gene in Iksan 515 and Iksan 526 did not significantly enhanced resistance against bacterial grain rot, bacterial leaf blight, sheath blight, and leaf blight. This study is the first report on the effect of resveratrol and piceid against pathogens of rice plant, and changes of disease resistance of transgenic rice plants transformed with stilbene synthase gene.

• 식물병연구
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• 제16권1호
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• pp.35-40
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• 2010

식물근권에서 유래된 12개의 근권세균이 Phytophthora citrophthora에 의해 발생되는 감귤 역병에 대해 감귤 열매에서 병진전 억제 효과를 나타내는지 조사하였다. 조사한 근권세균 중 THJ609-3, TRH423-3, BRH433-2, Lysochit 및 KRY505-3 등에 의해 역병이 억제되는 것을 역병균의 in vivo 상처접종을 통하여 밝혀졌다. 근권세균을 P.citrophthora의 균사체와 대치 배양하여 역병균 저지대의 길이를 측정한 결과 역병 진전억제효과를 보였던 5개의 균주에서 모두 항진균활성이 나타났다. 그러나 근권세균의 균사생장억제효과와 역병억제효과 사이에 양의 상관관계는 성립되지는 않았다. 한편, 근권세균 rDNA의 internal transcript spaces(ITS)을 분석을 통해 동정 한 결과 Lysochit과 KRY505-3은 Bacillus cereus로 동정 되었고, BRH4332은 B. circulans로, TRH423-3는 Burkholderia gladiol로 동정되었다. 이 연구는 친환경 농가와 같이 농약사용이 제한된 농장에서 감귤 역병에 대해 생물적 방제를 위한 활성균을 모색하는데 매우 가치가 있을 것으로 생각된다.

• 식물병연구
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• 제13권1호
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• pp.20-23
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• 2007

2002년부터 2005년까지 4년간 벼 흰잎마름병 초발병 조사결과 2002년보다 초발병일이 20$\sim$30일 이상 빨라지고 있음을 확인하였다. 벼 흰잎마름병 발병시기 및 병반면적율에 따라 수량이 감소하였는데 병반면적률이 10% 이하에서는 피해가 적었으나, 병반적율이 증가함에 따라서 수량감소가 점점 많아졌고, 25% 이상일 때부터 수량감소 및 현미천립중 등에서 현저히 낮아지고 병반면적율이 50% 이상이고 유수형성기 발병시 수량 29%, 현미천립중 2.3g, 현미완전립률 18%까지 감소되었다. 밥맛의 기준이 되는 식미치인 점도에서도 병반면적율이 증가함에 따라 낮은 식미치를 보였다.