• 식물병연구
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• 제26권2호
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• pp.88-94
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• 2020

Recently, the severe dieback of apple trees resulting from soil-borne diseases has occurred in South Korea. The casual agents of dieback were surveyed on 74 apple orchards that had been damaged nationwide in 2016-2019. The number of apple orchards affected alone by Phytophthora rot, violet root rot, and white root rot was 31, 34, and 3, respectively. Also, the total number of mixed infection orchards was 6. Out of 9,112 apple trees affected by dieback, the trees damaged by Phytophthora rot, violet root rot, and white root rot were 3,332, 3,831, and 44, respectively. Moreover, the total number of mixed infection apple trees was 1,905. The provinces mainly affected were Gyeongnam, Gyeongbuk, Chungbuk, and Jeonbuk. The survey on these infected apple orchards will be available to form management strategy for the dieback that had been increased by soil-borne fungal pathogens.

• 식물병연구
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• 제27권3호
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• pp.91-98
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• 2021

The current social demand for organic, sustainable, and eco-friendly approaches for farming, while ensuring the health and productivity of crops is increasing rapidly. Biocontrol agents are applied to crops to ensure biological control of plant pathogens. Research on the biological control of white root rot disease caused by a soil-borne pathogen, Rosellinia necatrix, is limited in pears compared to that in apple and avocado. This pathogenic fungus has an extensive host range, and symptoms of this disease include rotting of roots, yellowing and falling of leaves, wilting, and finally tree death. The severity of the disease caused by R. necatrix, makes it the most harmful fungal pathogen infecting the economical fruit tree species, such as pears, and is one of the main limiting factors in pear farming, with devastating effects on plant health and yield. In addition to agronomic and cultural practices, growers use chemical treatments to control the disease. However, rising public concern about environmental pollution and harmful effects of chemicals in humans and animals has facilitated the search for novel and environmentally friendly disease control methods. This review will briefly summarize the current status of biocontrol agents, ecofriendly methods, and possible approaches to control disease in pear orchards.

• 식물병과 농업
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• 제5권1호
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• pp.1-7
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• 1999

The grain rot of caused by Bukholderia glumae was fist reported in japan in 1955 and then reported in other countries as well as in Korea in 1986. The pathogen causes both seedling and grain rot of rice but it cannot attack any other parts of adult rice plant. Bacterial colonies grow slowly, and are circular and greyish white. The causal bacterium is Gram-negative and rod shape with 1-3 polar flagella, and produce a diffusible yellow-greenish nonfluorescent pigment on King's medium B. Biochemical characteristics such as negative in arginine dehydrolase, oxidase reaction and nitrate reduction and positive in lecithinase, and the utilization of L-arginine and inositol are useful in differentiation of this from other nonfluorescent bacteria pathogenic to rice. This pathogenic bacterium had belonged to the genus of Pseudomonas but recently was transferred to the new genus Burkholderia on the basis of physiological characteristics and DNA-DNA hybridization data. However, other characteristics such as colony heterogenicity or colonial variation after subcultures, phytotoxin, secreting antibiotics, and relationship between yellow greenish pigment production and pathogenicity need to be clarified more. To develop an effective control strategy for this disease, understanding of detailed life cycle of the disease and critical environmental factors affecting disease development is prerequisite. Although 5,435 ha of rice paddy in Korea was infested during 1998, there is no exact estimation of yield losses and distribution of the pathogen. The review will focus on recent progress on the understanding of the bacteriological and ecological characteristics of the causal bacterium and control means of the disease.

• 한국유기농업학회지
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• 제23권1호
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• pp.113-121
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• 2015

본 연구는 전작물 재배에 따른 마늘 흑색썩음균핵병 피해 경감 효과를 평가하기 위해 2 년간 수행되었다. 콩 참깨 호박 네마장황, 대파를 전작물로 재배하였으며, 대조구로 휴경처리구와 병원균 무접종구를 두었다. 전적물 재배 후 마을을 파종하고 재배하면서, 흑색썩음균핵병 이병주율과 수량을 조사하였다. 2013년 흑색썩음균핵병은 병원균 무접종구, 콩, 네마장황처리구에서 가장 낮았으며, 호박처리구에서 가장 높았다. 2014년에는 네마장황, 콩, 대파처리구에서 흑색썩음균핵병 이병주율이 낮았으며, 호박처리구에서 가장 높았다. 처리구 별 마늘의 수량은 2013년에는 콩, 네마장황, 대파 처리구에서 가장 높았고 호박처리구에서 가장 적었으며, 2014년에는 콩, 네마장황, 대파처리구에서 높았고, 호박처리구에서 가장 적어 이병주율과 유사한 경향을 보였다. 이상의 결과를 토대로 콩-마늘과 네마장황-마늘재배체계가 흑색썩음균핵병을 억제하기 위한 윤작체계가 될 수 있을 것으로 생각되었다.

• Mycobiology
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• 제47권1호
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• pp.87-96
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• 2019

Fungi produce various secondary metabolites that have beneficial and harmful effects on other organisms. Those bioactive metabolites have been explored as potential medicinal and antimicrobial resources. However, the activities of the culture filtrate (CF) and metabolites of whiterot fungus (Schizophyllum commune) have been underexplored. In this study, we assayed the antimicrobial activities of CF obtained from white-rot fungus against various plant pathogens and evaluated its efficacy for controlling anthracnose and gray mold in pepper plants. The CF inhibited the mycelial growth of various fungal plant pathogens, but not of bacterial pathogens. Diluted concentrations of CF significantly suppressed the severity of anthracnose and gray mold in pepper fruits. Furthermore, the incidence of anthracnose in field conditions was reduced by treatment with a 12.5% dilution of CF. The active compound responsible for the antifungal and disease control activity was identified and verified as schizostatin. Our results indicate that the CF of white-rot fungus can be used as an eco-friendly natural product against fungal plant pathogens. Moreover, the compound, schizostatin could be used as a biochemical resource or precursor for development as a pesticide. To the best of our knowledge, this is the first report on the control of plant diseases using CF and active compound from white-rot fungus. We discussed the controversial antagonistic activity of schizostatin and believe that the CF of white-rot fungus or its active compound, schizostatin, could be used as a biochemical pesticide against fungal diseases such as anthracnose and gray mold in many vegetables.

• 식물병연구
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• 제26권1호
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• pp.48-52
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• 2020

2019년 7월 안동지역 노지 재배지에서 복숭아에 과실 썩음병 피해가 발생하였다. 피해 과실에서는 병이 진전됨에 따라, 썩음증상과 함께, 흰색과 자주색을 띄는 균사 및 포자가 관찰되었다. 병원균을 순수 분리한 뒤, 건전한 복숭아 과일에 접종하였을 때 동일한 과실 썩음 증상을 유도하였다. 분리된 병원균의 internal transcribed spacer (ITS), translation elongation factor 1-alpha (TEF) 그리고 β-tubulin (β-TUB) sequence 분석을 통해 Fusarium avenaceum으로 동정되었다. 따라서, 이 증상을 Fusarium avenaceum에 의한 "복숭아 과실 썩음병"으로 명명하고자 한다. 분리된 균주는 농촌진흥청 국립농업과학원 미생물 은행[Korean Agricultural Culture Collection(KACC)]에 기탁되었다(KACC accession number 48936).

• 식물병연구
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• 제11권2호
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• pp.201-203
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• 2005

2004과 2005년 7월 경상남도 진주시 칠암동 남강변에 재배중인 비비추에서 S. rolfsii에 의한 흰비단병이 발생되었다. 병징은 잎자루, 줄기, 지제부위가 수침상으로 물러지고 부패하면서 암갈색으로 되고 시들어 말라 죽는다. 병반부와 지제부위의 토양 표면에 흰색의 곰팡이가 솜털처럼 생기고 갈색의 둥근 균핵을 많이 형성되었다. 감자한천 배지에서 갈색의 둥근 균핵을 많이 형성하였으며 크기는 $1\~3$mm였다. 균사의 폭은 $4\~8{\mu}m$이며, 균사생육 적온은 $30^{\circ}C$였다. 균사특유의 clamp connection이 관찰되었다. 비비추에서 발생한 병징과 균학적 특징 및 병원성을 검정한 결과, 이 병을 Sclerotium rolfsii Saccardo에 의한 비비추 흰비단병으로 명명하고자 한다.

• 식물병과 농업
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• 제1권1호
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• pp.37-44
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• 1995

This study was carried out to select effective fungicides against white and violet root rot caused by Rosellinia necatrix and Helicobasidium mompa with nine fungicides including thiophanate-methyl from 1993 to 1994. Through laboratory, greenhouse and field trials on inhibitory effect of mycelial growth and disease incidence against the two fungal pathogens, 5 fungicides have been selected finally. Thiopanate-methyl, benomyl, iminoctadine-triacetate and isoprothiolane were proven to have high control effect against R. necatrix. In addition to thiopanate-methyl and benomyl, tolclofos-methyl has been selected for effective control of H. mompa, since it showed prominent control effect in field trial than in laboratory or green house test.

• 한국균학회지
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• 제40권4호
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• pp.282-287
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• 2012

Sclerotium cepivrum은 마늘과 같은 파속작물에 발생하는 흑색썩음균핵병의 병원균이다. 기생진균 Paraconiothyrium minitans S134 균주는 마늘 흑색썩음균핵병의 생물적 방제를 위하여 선발되었다. 포장실험은 태안에서 2011년 10월부터 2012년 6월까지 실시하였다. P. minitans S134 균주의 포자현탁액($5{\times}10^6m{\ell}$)을 마늘 종구를 파종직후와 다음해 2월 하순에 주당 $100m{\ell}$씩 각각 관주처리하여 6월 5일에 흑색썩음균핵병 발생 억제효과를 조사하였다. P. minitans S134 균주를 2회 관주처리구가 6.8%, 플루퀀코나졸수화제 분의처리구가 0.4%, 무처리구가 19.5%의 흑색썩음균핵병이 발생하였다. 그러므로 P. minitans S134 균주는 마늘 흑색썩음균핵병에 대한 유망한 미생물농약으로서 가능성을 나타내었다.

• 한국균학회지
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• 제50권2호
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• pp.143-147
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• 2022

Sclerotinia rot symptoms were observed in stringy stonecrop (Sedum sarmentosum) plants growing in vinyl greenhouses in Yeoju and Icheon, Gyeonggi Province, Korea, during disease surveys in spring 2019 and 2020. The initial symptoms were soft rot on stems and leaves at or above the soil line. Furthermore, the symptoms progressed upwards, and the infected plant parts exhibited white to grayish-yellow discoloration. The infestation of diseased plants in the vinyl greenhouses was 1-5% at the two locations examined. Eight isolates of Sclerotinia sp. were obtained from lesions of the diseased plants. The isolates were identified as Sclerotinia sclerotiorum based on their morphological and molecular characteristics. In addition, artificial inoculation tested three isolates of S. sclerotiorum for pathogenicity on stringy stonecrop plants. All the tested isolates caused Sclerotinia rot symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the vinyl greenhouses investigated. This study is the first report of S. sclerotiorum causing Sclerotinia rot in stringy stonecrop.