• 한국지역사회생활과학회지
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• 제18권2호
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• pp.241-246
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• 2007

This study was conducted to select and screen for an antifungal bacterial strain showing pathogen inhibitory activity against Diaporthe actinidiae, which causes stem-end rot in kiwi fruit. Four bacterial strains were isolated which strongly inhibit Diaporthe actinidiae from among two hundred and fifty bacterial strains screened from the soil where kiwi fruit were grown. By co-culturing bacterial strain #72 and the pathogen causing the stem-end rot of kiwi fruit, bacterial strain #72 showed 81.0% antifungal activity against Diaporthe actinidiae. Bacterial strain #72 was identified to be from the genus Bacillus sp. based on morphological and biochemical characterization. The bacterialization of culture broth for Bacillus sp. #72 which was sterilized at $121^{\circ}C$ for 15 minutes and than purified by $0.45{\mu}m$ membrane filter showed almost all of the antagonistic activity against Diaporthe actinidiae. We have also confirmed that in vitro treatment of Bacillus sp. #72 cultured in SD+B+P(sugar 5%, soy sauce 3%, beef extract 0.2%, peptone 0.2%) medium efficiently inhibited the growth of Diaporthe actinidiae responsible for stem-end rot in kiwi fruit.

• The Plant Pathology Journal
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• 제17권2호
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• pp.110-113
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• 2001

Post-harvest diseases of kiwifruit caused severe damages on the fruits during storage, transportation, marketing and consumption. Phomopsis sp. was reported to be one of the major causal organisms of post-harvest fruit rots of kiwifruit. Symptoms of stem-end rot caused by Phomopsis sp. appeared at the stem-end area of the fruit as it ripened. The brown pubescent skin at the area became soft and lighter in color than the adjacent firm healthy tissues. A watery exudate and white mycelial mats were frequently visible at the stem-end area forming a water-drop stain down the sides on the dry brown healthy skin. When the skin was peeled back, the affected flesh tissue was usually watersoaked, disorganized, soft and lighter green than the healthy tissue. Phomopsis sp. was consistently isolated from the diseased fruits, and its pathogenicity was confirmed by an artificial inoculation test on healthy fruit of kiwifruits. The mycological characteristics of the telemorph state of the fungus produced on potato-dextrose agar were in accordance with those of Diaporthe actinidiae. This is the first report on the occurrence of a telemorph state of D. actinidiae as the causal organism of stem-end rot of kiwifruit in Korea.

• 식물병연구
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• 제9권4호
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• pp.201-204
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• 2003

Botryosphaeria dothidea, Diaporthe actinidiae 및 Botrytis cinerea에 의해 발생하는 참다래 저장병을 예방하기 위하여 참다래 최적 후숙 조건을 조사하였다. B. dothidea와 D. actinidiae의 균사 생육적온은 각각 $26{\sim}35^{\circ}C$와 $26{\sim}29^{\circ}C$였으며, B. cinerea의 균사 생육적온은 $20{\sim}26^{\circ}C$였으며, 저장병 발병율은 균사 생육적온과 밀접한 관계가 있었다. 참다래 과실을 후숙시킬 경우 고온일수록 후숙 기간을 단축시킬 수 있으나 후숙과 함께 저장병 발생도 증가하였다. 참다래 과실을 $17^{\circ}C$의 후숙 온도에서 20일 동안 후숙시키는 것이 가장 이상적인 후숙 조건이었다.

• 식물병연구
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• 제9권4호
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• pp.196-200
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• 2003

우리나라 참다래 주요 재배지인 전남과 경남 그리고 제주지역의 16개 포장에서 임의로 수집한 1600개 참다래 과실의 평균 저장병 발병율은 32.0%로 나타났지만, 저장병 발병율은 수확한 과수원에 따라서 5%에서 68%까지 다양했다. 저장병에 걸린 참다래 과실 중에서 15.4%가 외부 병징, 68.4%가 내부 병징을 나타내었고, 외부와 내부 모두에 병징을 나타내는 것은 16.2%였다. 저장병에 걸린 과실들에서 병원균의 검출율은 분리한 지역에 따라 차이가 있었으며, Botryosphaeria dothidea가 83.3%, Diaporthe actinidiae는 11.9%, Botrytis cinerea가 1.4%의 검출율을 보여 주요 저장병원균으로 밝혀졌다. 참다래 주요 저장병원균으로 확인된 B. dothidea와 D. actinidiae에 의해 발생하는 참다래 주요 저장병을 과실에 나타난 각 병징과 각 병원균들의 특성을 고려하여 과숙썩음병과 과실꼭지썩음병으로 각각 구분하여 명명하고자 한다.

• The Plant Pathology Journal
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• 제18권5호
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• pp.284-287
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• 2002

The antifungal activity of super reductive water (SRW) against plant pathogenic fungi was examined to extend its application to integrated pest management (IPM) for plant diseases. Diluted solutions ($\times$1/10, $\times$1/25, and $\times$1/50) of SRW inhibited fungal growth of kiwifruit soft rot pathogen, Diaporthe actinidiae, in a concentration dependent manner, When kiwifruits were inoculated on wounds with mycelium blocks, stock and diluted solutions successfully inhibited the disease development. In addition to the high pH of the SRW, fungistatic activity was also considered as the cause of the antifungal effect against the pathogen. Whereas conidial germination of Magnaporthe grisea was not affected by the diluted SRW solutions, appressorium formation was significantly inhibited in a concentration dependent manner, With little harmfulness to human health and environment SRW could be used to control plant pathogenic fungi, particularly appressorium-forming fungal pathogens.

• 식물병연구
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• 제9권3호
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• pp.170-173
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• 2003

포장에서 참다래 저장병균들에 의한 감염을 최소화할 수 있는 화학적 방제체계를 확립하기 위하여, 국내에서 참다래 저장병 약제로 등록된 베노밀 수화제와 지오판 수화제 등 2가지 약제를 대체할 수 있는 새로운 약제를 선발하기 위하여 본 연구를 실시하였다. 시험에 사용한 8가지 약제 중에서 후루실라졸 수화제, 이프로 수화제 및 터부코나졸 수화제는 모두 실내 시험을 통하여 국내에서 참다래 주요 저장병원균으로 밝혀진 Botryosphaeria dothidea, Diaporthe actinideae 및 Botrytis cinerea에 대해 탁월한 균사생장 저지효과를 나타내었을 뿐만 아니라 포장 시험에서도 베노밀 수화제와 지오판 수화제와 비등하거나 우수한 방제 효과를 나타내었으므로 장차 참다래 저장병 장제약제로 사용할 수 있을 것으로 기대된다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.99.2-99
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• 2003

An attempt was made to screen antifungal activities of Bacillus thuringiensis strains on various plant pathogens, Botryosphaeria dothidea, Diaporthe actinidiae, Botrytis cinerea, Glomerella cingulata, Colletorichum cocodes, Sclerotinia scierotiorum, Alternaria alternata, Helicobuidium mompa, Bipolaris coicis, Fusarium graminearum and Rhizoctosnia solani. Ten and forty-five strains of B. thuringiensis were isolated from animal feces in Korea and Japan, respectively. Inhibitory effects of the strains on the mycelial growth of the pathogens were examined on the mixed media of potato dextrose agar and nutrient agar. Approximately half of the strains inhibited the mycelial growth of one or more pathogens. Most of the pathogens were inhibited by any of the strains but Fusarium graminearum and Rhizoctonia solani were not inhibited at all. This is the first report that B. thuringiensis shows a potent antifungal activity on plant pathogens in Korea.

• The Plant Pathology Journal
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• 제22권4호
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• pp.381-385
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• 2006

Antifungal activity of Korean and Chinese lichen-forming fungi(LFF) was evaluated against plant pathogenic fungi of Botryosphaeria dothidea, Botrytis cinerea, Diaporthe actinidiae, Pestalotiopsis longiseta, Pythium sp., Rhizoctonia solani, and Sclerotium cepivorum. The LFF were isolated from Cladonia scabriuscula, Melanelia sp., Nephromopsis asahinae, Nephromopsis pallescens, Parmelia laevior, Pertusaria sp., Ramalina conduplicans, Ramalina sinensis, Ramalina sp., Umbilicaria proboscidea and Vulpicida sp. with discharged spore method. The isolates were deposited in the herbarium of Korean Lichen Research Institute(KoLRI) in Sunchon National University. The LFF of Melanelia sp., P. laevior, Pertusaria sp., R. conduplican and Ramalina sp. exhibited strong antifungal activity against all of the pathogenic fungi examined. Among them, LFF of P. laevior showed more than 90% of inhibition in fungal hyphae growth, compared with control. The results imply that LFF can be served as a promising bioresource to develop novel biofungicides. Mass cultivation of the LFF is now under progress in laboratory conditions for chemical identification of antifungal substances.

• The Plant Pathology Journal
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• 제38권1호
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• pp.25-32
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• 2022

Plant pathogens pose major threats on agriculture and horticulture, causing significant economic loss worldwide. Due to the continuous and excessive use of synthetic pesticides, emergence of pesticide resistant pathogens has become more frequent. Thus, there is a growing needs for environmentally-friendly and selective antimicrobial agents with a novel mode of action, which may be used in combination with conventional pesticides to delay development of pesticide resistance. In this study, we evaluated the potentials of lichen substances as novel biopesticides against eight bacterial and twelve fungal plant pathogens that have historically caused significant phytopathological problems in South Korea. Eight lichen substances of diverse chemical origins were extracted from axenic culture or dried specimen, and further purified for comparative analysis of their antimicrobial properties. Usnic acid and vulpinic acid exhibited strong antibacterial activities against Clavibacter michiganensis subsp. michiganensis. In addition, usnic acid and vulpinic acid were highly effective in the growth inhibition of fungal pathogens, such as Diaporthe eres, D. actinidiae, and Sclerotinia sclerotiorum. Intriguingly, the growth of Rhizoctonia solani was specifically inhibited by lecanoric acid, indicating that lichen substances exhibit some degrees of selectivity to plant pathogens. These results suggested that lichen substance can be used as a selective biopesticide for controlling plant disease of agricultural and horticultural significance, minimizing possible emergence of pesticide resistant pathogens in fields.

• The Plant Pathology Journal
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• 제24권3호
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• pp.322-327
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• 2008

Antifungal activities of natural substrances from Eucalyptus darlympleana, E. globules, E. gunnii and E. unigera were evaluated against postharvest pathogens of kiwifruits, Botrytis cinerea, Botryosphaeria dothidea, and Diaporthe actinidiae, to screen effective natural substances as an alternative to chemical fungicides. Methanol extract of the Eucalyptus trees showed strong antagonistic activity against the pathogenic fungi. Among them, E. unigera and E. darlympleana effectively inhibited mycelial growth of the pathogens. For chemical identification of the antifungal substances, the methanol extract of E. darlympleana leaves was successively partitioned with $CH_2Cl_2$, EtOAc, n-BuOH and $H_2O$. Among the fractions, $CH_2Cl_2$ and n-BuOH showed strong inhibitory activity of mycelial growth of the fungi. Five compounds were isolated from EtOAc and n-BuOH fractions subjected to $SiO_2$ column chromatography. Two phenolic compounds(gallic acid and 3,4-dihydroxybenzoic acid) and three flavonoid compounds(quercetin, quercetin-3-O-$\alpha$-L-rhamnoside, quercetin-3-O-$\beta$-glucoside) were identified by $^1H$-NMR and $^{13}C$-NMR spectroscopy. Among them, only gallic acid was found to be effective in mycelial growth and spore germination of B. cinerea at relatively high concentrations. The results suggest that gallic acid can be a safer and more acceptable alternative to current synthetic fungicides controlling soft rot decay of kiwifruit during postharvest storage.