• The Plant Pathology Journal
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• 제18권4호
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• pp.199-203
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• 2002

Soft rot occurred severely in onion bulbs stored under low temperature ($5^{\circ}C$) in storage houses at Changyoung, Kyungnam province, Korea in early 2000. Water-soaking and yellowish-brown lesions initially appeared on the outside scales of diseased onion bulbs, gradually progressing into the inside scales. Among the bacterial isolates obtained from the lesions, K-2 isolate was found to be responsible for the disease, which grew at a temperature range of from $0^{\circ}C$ to $36^{\circ}C$ with optimum temperature of $00^{\circ}$-$33^{\circ}C$. However, it showed strong pathogenicity to onion bulbs at $25^{\circ}C$ and $5^{\circ}C$ at 3 days and 2 months, respectively. The bacterium also caused soft rot on potato and showed hypersensitive reactions to tobacco and potato. The causal bacterium of onion soft rot was identified as Pseudomonas marginalis based on morphological, biochemical, and physiological characteristics including LOPAT, Soft rot in onion under low temperature storage caused by P. marginalis has not been previously reported.

• 한국유기농업학회지
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• 제26권1호
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• pp.129-140
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• 2018

Pectobacterium carotovorum subsp. carotovorum은 배추를 포함한 대부분의 채소작물에 강한 병원성을 나타낸다. 포장 방제 효과 검정을 통하여 배추 무름병 억제인자로 선발된 CAB12243-2 균주는 16S rRNA gene의 염기서열 상동성 분석으로 Bacillus toyonensis로 확인되었다. B. toyonensis CAB12243-2 균주는 무름병균의 펙틴분해 작용을 억제하였고 탄소원으로 glucose와 trehalose를 이용하였다. 또한 이 균주는 '노랑봄' 품종으로 봄배추 재배 시 73%, '불암3호' 품종으로 가을배추 재배 시 68.9%의 포장 방제 효과를 보였다. 이러한 결과로 B. toyonensis CAB12243-2 균주는 채소류의 무름병에 대한 효과적인 생물적 방제제로 활용이 가능한 것을 확인할 수 있었다.

• 한국식물병리학회지
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• 제11권2호
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• pp.116-119
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• 1995

강원도 인제지역에서 집단재배되고 있는 치커리에 무름병이 관찰되었다. 병징 초기증사은 치커리 뿌리에서 무름증상을 나타내는 것을 시작으로 시간이 지남에 다라 병징부위가 점차적으로 확대되어 뿌리가 완전히 부패되었다. 뿌리의 연부증상은 치커리 지상부위를 마르게하여 결국은 고사시켰다. 병반부로부터 분리한 병원균은 생리, 화학적특성과 Biolog program의 결과에 따라 Erwinia carotovora subsp. corotovora로 동정되었다. E. carotovora subsp. carotovora에 의한 치커리의 무름병은 국내에서 보고된 바가 없기에, 본 세균에 의한 병을 "치커리 세균성무름병(bacterial soft rot of chicory)" 이라 명명할 것을 제안한다.

• 식물병연구
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• 제19권1호
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• pp.49-54
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• 2013

Sclerotinia white rot disease was observed on 5 and 6-year-old ginseng (Panax ginseng) roots in Hongchun, Cheorwon, and Yanggu, Gangwon Province, Korea from 2006 to 2010. Symptoms included a brownish watery soft rot of the roots, and black sclerotia were often found on the rotten roots. The causal agent of the disease was identified as Sclerotinia nivalis based on cultural characteristics and sequence analyses of the internal transcribed spacer region of rDNA and ${\beta}$-tubulin gene with 100% sequence similarity. Pathogenicity tests were performed on 2-year-old ginseng roots with mycelium plugs without wounds. A watery soft rot of the roots and black sclerotia were observed 10 days after inoculation. These symptoms were identical to those observed on naturally infected roots. The same fungus was re-isolated from the lesions induced by artificial inoculation. This is the first report of sclerotinia white rot caused by S. nivalis on P. ginseng in Korea.

• 농업과학연구
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• 제16권1호
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• pp.19-25
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• 1989

전국(全國)의 주요(主要) 재배단지(栽培團地)와 시장(市場)으로 부터 양파 부패병반(腐敗病斑)을 수집(蒐集)하여 병원세균(病原細菌)을 분리(分離)하였다. 분리세균(分離細菌)의 세균학적(細菌學的) 특성(特性)과 병원성(病源性)에 따라 분리세균(分離細菌)은 Erwinia carotovora subsp. carotovora, E. rhapontici, 및 E. chrysanthemi로 동정(同定)되었다. 경우에 따라서는 한개의 양파 병반(病斑)으로 부터 2 종류(種類)의 세균(細菌)이 분리(分離)되는 것으로 보아 포장(圃場)이나 저장중(貯藏中)에 2 종류(種類)의 세균(細菌)이 복합감염(複合感染)된 것으로 추정되었다. 따라서, E. carotovora subsp. carotovora, E. rhapontici 및 E. chrysanthemi에 의한 양파 세균성(細菌性) 썩음병을(病) 통합(統合)하여 "양파 무름병(病)" (bacterial soft rot of onion)으로 할것을 제안(提案)한다.

• The Plant Pathology Journal
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• 제39권1호
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• pp.62-74
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• 2023

Plant pathogenic Pectobacterium species cause severe soft rot/blackleg diseases in many economically important crops worldwide. Pectobacterium utilizes plant cell wall degrading enzymes (PCWDEs) as the main virulence determinants for its pathogenicity. In this study, we screened a random mutant, M29 is a transposon insertion mutation in the metC gene encoding cystathionine β-lyase that catalyzes cystathionine to homocysteine at the penultimate step in methionine biosynthesis. M29 became a methionine auxotroph and resulted in growth defects in methionine-limited conditions. Impaired growth was restored with exogenous methionine or homocysteine rather than cystathionine. The mutant exhibited reduced soft rot symptoms in Chinese cabbages and potato tubers, maintaining activities of PCWDEs and swimming motility. The mutant was unable to proliferate in both Chinese cabbages and potato tubers. The reduced virulence was partially restored by a complemented strain or 100 µM of methionine, whereas it was fully restored by the extremely high concentration (1 mM). Our transcriptomic analysis showed that genes involved in methionine biosynthesis or transporter were downregulated in the mutant. Our results demonstrate that MetC is important for methionine biosynthesis and transporter and influences its virulence through Pcc21 multiplication in plant hosts.

• 식물병연구
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• 제30권1호
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• pp.88-94
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• 2024

In July 2021, symptoms of soft rot were observed on the stems of Ficus carica in Yeongam, Jeollanamdo, Korea. To accurately diagnose the cause, infected stem was collected and bacterial strain was isolated. Among these, the pathogenic strain KNUB-08-21 was identified as Pectobacterium aroidearum through 16S rRNA gene sequencing and phylogenetic analysis based on the concatenated sequences of the dnaX, leuS, and recA genes. The affiliation of the isolate with this bacterial species was also confirmed by its biochemical characteristics obtained using API ID 32 GN system. Artificial inoculation confirmed the strain's pathogenicity in figs, causing significant damage to both stems and fruits. To our knowledge, this is the first report of P. aroidearum causing soft rot disease in F. carica in Korea.

• 식물병연구
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• 제28권3호
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• pp.166-171
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• 2022

Commercial products with antibiotics like streptomycin as active ingredients have been used to control soft rot disease caused by Pectobacterium species for a long time. In this study, antibiotic resistance of twenty-seven Korean strains of Pectobacterium species including P. carotovorum, P. odoriferum, P. brasiliense, and P. parmenteri, which were previously shown to be susceptible to the bacteriophage phiPccP-1 was surveyed using a disk diffusion assay. While all strains were highly susceptible to ampicillin, kanamycin, chloramphenicol, tetracycline, and rifampicin, some strains showed weak susceptibility to 300 ㎍/ml of streptomycin. Furthermore, some of them are partially or completely resistant to commercial pesticides-Buramycinand streptomycin at the concentration of 250 ㎍/ml that is recommended by the manufacturer for streptomycin-based pesticides. These results indicate the presence of streptomycin-resistant Pectobacterium strains in South Korea, and the development of antibiotic alternatives to control soft rot is needed.

• Mycobiology
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• 제32권2호
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• pp.98-101
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• 2004

A fruit soft rot caused by Mucor piriformis occurred on sweet persimmon storages in Jinju, Changwon and Gimhae, Gyeongnam province, Korea, 2003. The disease infection usually started from wounding after cracking of fruits. At first, the lesions started with water soaked and rapidly softened and diseased lesion gradually expanded. Colonies on potato dextrose agar at $20^{\circ}C$ were whitish to olivaceous-buff Sporangia were globose, black and $96{\sim}153{\mu}m$ in size. Sporangiophores were $26{\sim}42{\mu}m$ in width. Sporangiospores were ellipsoid and $5.8{\sim}10.6{\times}4.3{\sim}7.6{\mu}m$ in size. Columella was obovoid, cylindrical-ellipsoidal, pyriform, subglobose and $80{\sim}125{\mu}m$ in size. Optimal temperature for mycelial growth was $20^{\circ}C$ on PDA. The causal organism was identified as M. piriformis. This is the first report of fruit soft rot on sweet persimmon caused by M. piriformis in Korea.

• Mycobiology
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• 제33권4호
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• pp.240-242
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• 2005

A soft rot of fruits caused by Mucor racemosus occurred on cherry tomato collected in Agricultural Products Wholesale Market in Jinju, Korea. The disease infection usually occurred wounded areas after cracking of fruits. At first, the lesions started with water soaked and rapidly softened and diseased lesion gradually expanded. Colonies were white to brownish to gray in color. Sporangia were $32{\sim}54\;{\mu}m$ in size and globose in shape. Sporangiophores were $8{\sim}14\;{\mu}m$ in width. Sporangiospores were $5{\sim}12\;{\times}\;4{\sim}8\;{\mu}m$ in size, ellipsoidal to subglobose in shape. Columella was $27{\sim}42\;{\mu}m$ in size, obovoid, ellipsoidal, cylindrical-ellipsoidal, slightly pyriform in shape. Chlamydospores were numerous in sporangiophores and barrel-shaped when young, subglobose in old cultures. Optimum growth temperature was about $25^{\circ}C$. The fungus was identified as M. racemosus Fres.. This is the first report of soft rot on cherry tomato caused by M. racemosus in Korea.