• The Plant Pathology Journal
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• 제33권1호
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• pp.95-100
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• 2017

Fungicide-resistant Alternaria alternata impede the practical control of the Alternaria diseases in crop fields. This study aimed to investigate cytological fungicide resistance mechanisms of A. alternata against dicarboximide fungicide iprodione. A. alternata isolated from cactus brown spot was cultured on potato-dextrose agar (PDA) with or without iprodione, and the fungal cultures with different growth characteristics from no, initial and full growth were observed by light and electron microscopy. Mycelia began to grow from one day after incubation (DAI) and continued to be in full growth (control-growth, Con-G) on PDA without fungicide, while on PDA with iprodione, no fungal growth (iprodione-no growth, Ipr-N) occurred for the first 3 DAI, but once the initial growth (iprodione-initial growth, Ipr-I) began at 4-5 DAI, the colonies grew and expanded continuously to be in full growth (iprodione-growth, Ipr-G), suggesting Ipr-I may be a turning moment of the morphogenetic changes resisting fungicidal toxicity. Con-G formed multicellular conidia with cell walls and septa and intact dense cytoplasm. In Ipr-N, fungal sporulation was inhibited by forming mostly undeveloped unicellular conidia with degraded and necrotic cytoplasm. However, in Ipr-I, conspicuous cellular changes occurred during sporulation by forming multicellular conidia with double layered (thickened) cell walls and accumulation of proliferated lipid bodies in the conidial cytoplasm, which may inhibit the penetration of the fungicide into conidial cells, reducing fungicide-associated toxicity, and may be utilized as energy and nutritional sources, respectively, for the further fungal growth to form mature colonies as in Ipr-G that formed multicellular conidia with cell walls and intact cytoplasm with lipid bodies as in Con-G.

• 식물병연구
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• 제27권4호
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• pp.164-171
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• 2021

2020년 8월에 전라북도 순창군 소재 25개 고추 재배지에서 채집한 탄저병 감염 과실로부터 377개 탄저병균주를 분리한 후 지역별로 선발된 62개 균주를 대상으로 국내에 등록된 11개의 고추 탄저병 살균제에 대한 균사생장억제율을 조사하여 각각의 살균제에 대한 감수성 정도를 조사하였다. 살균제에 대한 탄저병균의 살균제 감수성 실험 결과 fluazinam, prochloraz manganese, benomyl에서는 저항성 균주가 관찰되지 않았으나 이외의 약제에서는 최소 3개의 지역에서 저항성 균주가 출현하였으며, dithianon은 모든 지역의 모든 균주가 저항성이었다. 이를 통해 일부 지역에서 살균제의 지속적인 처리로 인하여 균주집단 내 살균제 내성이 발현되었음을 확인할 수 있었다. 지역별로는 순창읍과 팔덕면에서 7개 농약에 대한 저항성 균주가 출현하였고, 금과면, 복흥면, 쌍치면, 유등면, 풍산면에서 6개 농약에 대한 저항성 균주가 출현하였음을 확인하였다. 약제 등록시기와 저항성 균주의 출현에는 유의미한 상관관계가 없었다.

• 농업과학연구
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• 제51권2호
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• pp.205-216
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• 2024

Although Aster yomena has recently attracted attention for its potential anti-cancer, antimicrobial, and immune-boosting effects, there are concerns about residual pesticides because they are consumed in salad-like forms. This study investigated residual characteristics and human dietary risks of the imidazole fungicide prochloraz applied to the herbal medicine Aster yomena with different spray frequency and timing. Residual analysis of prochloraz and its three main metabolites (BTS44595, BTS44596, and 2,4,6-trichlorophenol) in Aster yomena samples was performed using the QuEChERS method and LC-MS/MS. Mean recovery rates of the fungicide and its metabolites were satisfactory in the range of 80.1 ± 1.2% to 108.2 ± 3.8%. The residual concentration of the fungicide calculated as the sum of prochloraz and its metabolites was the highest (4.14 mg·kg^-1) in the Aster yomena sample applied three times at weekly intervals with the fungicide until immediately before harvest. The fungicide residue concentration in the Aster yomena was below the method-limit of quantification (MLOQ) when it was applied twice at the interval of 9 day until 21 days before harvest. The theoretical maximum daily intake of prochloraz, calculated based on the daily intake of Aster yomena, mean adult body weight, and the highest residue level analyzed in the this study, was safe at < 80% of the acceptable daily intake of the fungicide (0.01 mg^-1·kg·bw^-1·day). In conclusion, the triple application method with prochloraz at weekly intervals until the harvest day is recommended to produce safe Aster yomena from the fungicide residues and risks to humans.

• 농약과학회지
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• 제19권1호
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• pp.54-63
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• 2015

골프장이나 잔디 재배지에서 분리된 방선균을 대상으로 잔디병 방제 약제에 대한 약제 반응 조사한 결과 트리아졸계(Triazole) 약제 3종에 대한 반응은 PR 약제의 경우 시험 균주에 가장 영향을 미치지 않았고 다음으로 SR 약제로 나타났다. 반면에 HR 약제에 대하여 모든 균주는 생장하지 않는 것으로 나타났다. 스트로빌루린계(Strobilurin) 3종에 대한 반응은 선발된 균주 모두 유사하게 나타났다. CB와 AP 약제 경우 균주의 생장과 포자형성이 잘되었으나 CBA 약제 경우 2배 농도에서 선발된 균주 모두 포자형성이 되지 않았다. 아닐라이드계(Acetanilide) 2종에 대한 반응은 MK 약제보다 KT 약제 잘 생장하였다. 유기유황계(Organosulfur) 2종 대한 약제반응은 AT 약제에서 잘 생장하였으며 ATR 약제에서는 자라지 않는 것으로 나타났다. 카바메이트계(Carbamate) 1종, 유기인계(Organophosphate) 1종과 시아노피롤계(Cyanopyrrole) 1종에 대하여 시험 균주는 생장에 거의 영향을 받지 않는 것으로 나타났으나 퀴논계 + 스트로빌루린계(Quinone + Strobilurin) 혼합제 1종과 이미다졸계 + 트리아졸계(Imidazole + Triazole) 1종에 대하여는 전혀 생장하지 않는 것으로 나타났다.

• The Plant Pathology Journal
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• 제24권4호
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• pp.447-452
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• 2008

Four hundred and sixty six isolates of B. cinerea were obtained from infected leaves, stems and fruits of paprika grown in greenhouses or plastic film houses in Gangwon province, Korea, between August and November in 2006 and 2007. These isolates were classified into five representative phenotypes of resistant (R) and sensitive (S) reactions as SSR, SRR, RSS, RRS and RSR according to the responses of isolates against benzimidazole, dicarboximide and N-phenyl-carbamate fungicide in order. The percentage of five phenotypes were 51.3, 2.4, 35.6, 8.1 and 2.6%, respectively. The SSR phenotype (51.3%) was the most common. Among the nineteen fungicide products evaluated to compare their efficacy against gray mold pathogen on the paprika fruit inoculated with fungal mycelia, the mixture of diethofencarb and carbendazim was the most effective followed by iprodione, boscalid, the mixture of iprodione and thiophanate-methyl, fludioxonil, polyoxin-B, fluazinam, the mixture of tebuconazole and tolyfluanid and procymidone; while in the assay methods inoculated with fungal spores, the mixture of tebuconazole and tolyfluanid was the most effective in controlling gray mold followed by boscalid, fludioxonil, the mixture of diethofencarb and carbendazim and the mixture of pyrimethanil and chlorothalonil.

• 한국식물병리학회지
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• 제10권4호
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• pp.297-304
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• 1994

This study was carried out to develop bioassay for detection of pesticide residues in agricultural products by using the soil microbial isolates sensitive to pesticides. One hundred bacterial isolates and eighty five fungal isolates were obtained from soil and their sensitivity to 10 ppm of several pesticides was examined in vitro. Five bacterial isolates and three fungal isolates were found sensitive to organochloride fungicide and two fungal isolates sensitive to organocopper fungicide. Among these isolates, B46, B93 and F67 were tested to find out the difference in sensitivity according to the methods of fungicide treatment. All of the isolates were found sensitive to 10 ppm of organochloride fungicides mixed directly in PDA. But they were found insensitive to the fungicide mixed in PDA after filtering through membrane filter. In case of organocopper fungicide, the isolates were found sensitive only when it was treated in PDA. And their sensitivity showed difference among various kinds of organochloride fungicides. B46 and B93 were employed to check the possibility as the agent for detection of the pesticidal residues in twenty eight agricultural products including rice. It was found that all samples had not residues because the samples did not inhibit the growth of isolates. When organochloride fungicides were applied to the above products, it was possible to detect the residues in fruits and vegetables at the concentration of 10 ppm, but not in starch-rich grains. B46 and B93 were identified as Bacillus sp. according to their bacterial characteristics in culture.

• The Plant Pathology Journal
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• 제18권5호
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• pp.271-278
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• 2002

The effect of five plant population densities [5 (D$_1$), 10 (D$_2$), 20 (D$_3$), 30 (D$_4$), and 40 (D$_{5}$) plants/m$^2$] of four groundnut cultivars [ICGV 86699, ICG (FDRS) 10, ICGS 11 and TMV 2] and fungicide application (Kavach, chlorothalonil) to manage late leaf spot (LLS) and rust were studied in a field experiment during the 1995 and 1996 rainy seasons. LLS and rust severities were low in fungicide sprayed plots in all the cultivars irrespective of plant densities. Severities of LLS and rust, and percentage defoliation caused by LLS were significantly more in higher plant densities (D$_4$, D$_{5}$) than in lower plant densities (D$_1$, D$_2$, D$_3$) in fungicide sprayed and unsprayed plots in all the cultivars. All the cultivars gave significantly higher haulm and pod yields in fungicide sprayed plots than in unsprayed plots. Haulm and pod yields were significantly higher in higher plant densities than in lower plant densities. A combination of higher plant densities (D$_4$, D$_{5}$) and fungicide protection against LLS and rust gave maximum yield.yield.

• The Plant Pathology Journal
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• 제31권2호
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• pp.115-122
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• 2015

Anthracnose, caused by Colletotrichum gloeosporioides (C. gloeosporioides; Teleomorph: Glomerella cingulata), is the most destructive disease that affects sweet persimmon production worldwide. However, the biology, ecology, and genetic variations of C. gloeosporioides remain largely unknown. Therefore, in this study, the development of fungicide resistance and genetic diversity among an anthracnose pathogen population with different geographical origins and the exposure of this population to different cultivation strategies were investigated. A total of 150 pathogen isolates were tested in fungicide sensitivity assays. Five of the tested fungicides suppressed mycelial pathogen growth effectively. However, there were significant differences in the sensitivities exhibited by the pathogen isolates examined. Interestingly, the isolates obtained from practical management orchards versus organic cultivation orchards showed no differences in sensitivity to the same fungicide. PCR-restriction fragment length polymorphism (RFLP) analyses were performed to detect internal transcribed spacer regions and the ${\beta}$-tubulin and glutamine synthetase genes of the pathogens examined. Both the glutamine synthetase and ${\beta}$-tubulin genes contained a complex set of polymorphisms. Based on these results, the pathogens isolated from organic cultivation orchards were found to have more diversity than the isolates obtained from the practical management orchards.

• The Plant Pathology Journal
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• 제15권6호
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• pp.340-344
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• 1999

Fungicide-resistant isolates of Monilinia fructicola grew readily on media amended with 0.1, 1.0, 10, 100 and $1,000\mu\textrm{g}$ a.i./ml of carendazim, benomyl, or thiophanate-methyl. However, sensitive isolates did not grow on media amended even with $0.1\mu\textrm{g}$ a.i./ml of carbendazim, $1.0\mu\textrm{g}$ a.i./ml of benomyl or thiophanate-methyl. The fitness compositions including mycelial growth on fungicide-free medium, sporulation on fungicide-free medium and pear, and virulence on pear were not different between resistant and sensitive isolates. The resistant isolates persisted carbendazim resistance during multiple subdulturing and long term storage. The competitive ability of resistant isolates obtained from peach orchards in Korea was similar to those of sensitive isolates.

• 한국균학회지
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• 제19권1호
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• pp.85-87
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• 1991

Prochloraz of fungicide was applied on Mycogone perniciosa causing wet bubble in cultivated mushroom, Agaricus bisporus. In vitro, Prochloraz was an excellent fungicide on two strains of Mycogone, tolerant and non-tolerant to Benomyl, respectively. At the low dosage, Prochloraz more inhibited mycelial growth of mushrooms than Benomyl. At the higher dosage, Benomyl more inhibited the mycelial growth than prochloraz. The higher yield of sporophore of the mushroom with low inferction rate was abtained from several trial of Prochloraz. Prochloroz was concluded to be effective fungicide on Mycogone perniciosa on Agaricus cultivation.