• 한국응용곤충학회지
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• 제22권3호
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• pp.181-185
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• 1983

강원도 철원군 동송읍 일대의 인삼근부병을 조사한 결과 감자썩이선충(Ditylenchus destructor)을 분리 동정하였으며 이 선충이 인삼근부병의 한 원인임이 확인되었다. 이지역 인삼재식지 조사면적의 약 $36\%$인 $28,050m^2$가 이 선충으로 인하여 피해를 입었다. 이 선충에 걸린 인삼은 주로 주근(Tap root)의 피층이 갈변하고 Sponge 화되며 피층내부에 Cork 조직이 발달하여 부리가 잘부러진다. 이런 뿌리는 표피가 잘 벗겨지고 심한경우에는 뿌리에 내공이 생기거나 뿌리전체가 썩어 없어지며 줄기와 잎은 급격히 푸른채로 시들어 죽는다. 잎이시드는 병징이 있는 포장에서는 감자썩이선충이 $8.5\~222$마리/30g 이었고 병징이 나타나지 않은 포장에서는 $0\~7.0$ 마리였다.

• The Plant Pathology Journal
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• 제17권6호
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• pp.315-324
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• 2001

Tobacco (Nicotiana tabacum cvs.Xanthi-nc and NC 82) plants infected with Tobacco mosaic virus (TMV) were examined ultrastructurally. Local lesions produced by TMV were sunken and withered. The plants were subjected to temperature shift (TS), a method to produce programmed cell death (PCD), by placing the infected plants initially at high temperature (35$^{\circ}C$) for 2 days and then shifting them to greenhouse temperature (22-27$^{\circ}C$). As a result, expanded lesions around the original necrotic lesions were produced. The expanded area initially had no symptoms, but it withered and became necrotic 15 h after TS. No ultrastructural changes related to PCD were noted at 0 h after TS in Xanthi-nc tobacco tissues as well as in healthy and susceptible tobacco tissues infected with TMV, At 6 h after TS, chloroplasts were convoluted and cytoplasm began to be depleted; however no necrotic cells were found. At 17 h after TS, ground cytoplasm of affected cells was completely depleted and chloroplasts were stacked together with bent cell wall or dispersed in the intracellular space. Necrotic cells were also observed, containing virus particles in the necrotic cytoplasm. There were initially two types of symptoms in the expanded lesions: chlorosis and non-chlorosis (green). Abundant TMV particles and X-bodies were only found in the chlorotic tissue areas. These results suggest that PCD by TMV infection may start with the wilting of cells and tissues before necrotic lesion formation.

• 한국균학회지
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• 제47권4호
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• pp.427-435
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• 2019

최근 경남 산청, 함양의 딸기 재배지역의 육묘하우스에서 딸기 묘목의 뿌리와 관부를 썩게 하고 지상부의 생육을 저해하며 최종적으로 식물체를 시들게 하는 뿌리썩음병(가칭)증상이 발생하였다. 이러한 병반을 나타내는 딸기 식물체 뿌리와 관부로부터 병원균을 분리하고 균학적 특성을 조사하였으며, 유전자 염기서열 분석과 계통학적 분석을 수행하였다. 그 결과, 딸기 육묘과정에서 발생한 뿌리썩음병(가칭)의 병원균은 Neopestalotiopsis clavispora로 확인되었으며, 건전한 딸기 식물체를 대상으로 접종실험을 수행한 결과 딸기에 대한 병원성을 확인하였다. 지금까지 국내에서 N. clavispora에 의한 딸기 뿌리썩음병이 보고되지 않았으므로 본 연구결과를 바탕으로 이병을 딸기뿌리썩음병으로 국내 최초로 보고한다.

• The Plant Pathology Journal
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• 제36권5호
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• pp.450-458
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• 2020

Pepper and tomato plants infected with two Clavibacter species, C. capsici and C. michiganensis have shown different patterns of disease development depending on their virulence. Here, we investigated how pepper and tomato plants respond to infection by the high-virulent or low-virulent Clavibacter strains. For this, we chose two strains of each Clavibacter species to show different virulence level in the host plants. Although low-virulent strains showed less disease symptoms, they grew almost the same level as the high-virulent strains in both plants. To further examine the response of host plants to Clavibacter infection, we analyzed the expression patterns of plant defense-related genes in the leaves inoculated with different strains of C. capsici and C. michiganensis. Pepper plants infected with high-virulent C. capsici strain highly induced the expression of CaPR1, CaDEF, CaPR4b, CaPR10, and CaLOX1 at 5 days after inoculation (dai), but their expression was much less in low-virulent Clavibacter infection. Expression of CaSAR8.2 was induced at 2 dai, regardless of virulence level. Expression of GluA, Pin2, and PR2 in tomato plants infected with high-virulent C. michiganensis were much higher at 5 dai, compared with mock or low-virulent strain. Expression of PR1a, Osmotin-like, Chitinase, and Chitinase class 2 was increased, regardless of virulence level. Expression of LoxA gene was not affected by Clavibacter inoculation. These results suggested that Clavibacter infection promotes induction of certain defense-related genes in host plants and that differential expression of those genes by low-virulent Clavibacter infection might be affected by their endophytic lifestyle in plants.

• 한국작물학회지
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• 제44권3호
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• pp.282-287
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• 1999

The object of this study was to determine the difference of the time course changes of transpiration, diffusion resistance and photosynthetic rate of rice at several different growth stages subjected to soil moisture stress (SMS) and recovery by irrigation. A japonica rice cultivar 'Dongjinbyeo', was grown under flooded condition in a plastic container filled with silty loam soil. At 5 main growth stages, the container was treated by SMS until initial wilting point (IWP) and then reirrigated. The duration of SMS until IWP were the longest, 13 days for tillering stage, and the shortest, 7 days for panicle initiation and meiosis stage. The transpiration rate rapidly decreased during SMS and the transpiration rate at IWP of the stressed plant showed 10∼20% compared with control, and the transpiration rate of stressed plant at most growth stages also recovered rapidly after irrigation and then reached 100% of control within a week. The shoot photosynthetic rate in all growth stages rapidly decreased by SMS, and the rates at IWP of stressed plants were de-creased nearly to 0%, beside the treatment at tillering stage. The recovery degree of photosynthetic rate by irrigation ranged from 20 to 90%, showed higher at early growth stages of SMS treatment than that of later stages. At all growth stages the leaf diffusion resistance of stressed plants was over 3 times that of the control resulting from a rapid increase at 3 to 5 days after draining for SMS, and showed quick recovery by irrigation within 3 days after drainage. The above physiological parameters changed in close relation with the decrease of the soil matric potential after SMS. These results indicate that at all main growth stages of rice plants the transpiration and photosynthesis reduction by stomatal closure reponded sensitively to the first stage of SMS closely related with decrease of soil water potential, while those recovery pattern and recovered degree by irrigation are little different by growth stage of rice.

• 한국응용곤충학회지
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• 제26권1호
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• pp.25-30
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• 1987

참깨줄기의 반쪽부분(部分)만이 특징적으로 변색(變色)되며 결국은 식물체전체(植物體全體)가 고사(枯死)되는 병미(病微)이 장려품종(奬勵品種)인 광산(廣産)깨와 풍년(豊年)깨가 심겨진 포장(圃場)에서 관찰(觀察)되었다. 병미(病微)은 처음에 줄기의 한쪽 부분(部分)만이 수침상(水浸狀)의 줄무늬(條斑)형태(形態)로 변색(變色)되며, 병징후기(病徵後期)에는 변색부위상(變色部位上)에 황백색(黃白色)$\sim$선홍색(鮮紅色)의 Fusarium 포자퇴(胞子堆)들이 많이 형성(形成)된다. Fusarium oxysporum에 감염(感染)된 참깨 유묘(幼苗)에서는 주로 시들음 증상(症狀)이 나타나지만, 성묘(成苗)에서는 토양접종(土壞接種)이나 상처접종(傷處接種)에 의해 줄기반쪽썩음증상(症狀)을 재현(再現)시킬 수 있었다. 본(本) 병해(病害)는 주로 생육후기(生育後期)인 7월하순(月下旬) 경에 많이 발생(發生)된다. 참깨줄기반쪽썩음증상(症狀)에서 분리(分離)한 Fusarium oxysporum의 균학적(菌學的) 특성(特性)을 이미 참께시들음병(病)에서 보고(報告)되어 있는 Fusarium 균(菌)들과 비교(比較)한 결과(結果) 본(本) 균(菌)은 F. oxysporum f. sp. sesame로 생각된다.

• 식물병연구
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• 제14권2호
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• pp.131-133
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• 2008

2006과 2007년 2년간 경상남도농업기술원 약초 전시포장에 재배중인 꽃향유에서 S. rolfsii에 의한 흰비단병이 발생되었다. 병징은 줄기와 지제부위가 수침상으로 물러지고 부패하면서 암갈색으로 시들어 말라 죽는다. 병반부와 지제부위의 토양 표면에 흰색의 곰팡이가 솜털처럼 생기고 감자한천 배지에서 갈색의 둥근 균핵을 많이 형성하였으며 크기는 $1{\sim}3mm$였다. 균사의 폭은 $4{\sim}9{\mu}$이며 균사생육 적온은 $30^{\circ}C$였으며 균사특유의 clamp connection이 관찰되었다. 꽃향유에서 발생한 병징과 균학적 특징 및 병원성을 검정한 결과, 이 병을 Sclerotium rolfsii Saccardo에 의한 꽃향유 흰비단병으로 명명하고자 한다.

• 식물병연구
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• 제17권2호
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• pp.225-227
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• 2011

2009년 9월에 전북 완주군 상관면 조경포장에 재배중인 구절초의 줄기와 지제부위가 수침상으로 무르고 썩으면서 암갈색으로 시들어 말라 죽었다. 병반부와 지제부위의 토양 표면에 흰색의 균사가 자라고 갈색의 구형 또는 부정형의 균핵이 형성되었다. 균사의 생육적온은 $25{\sim}30^{\circ}C$이었으며, 균사의 폭은 4-9 ${\mu}m$이었고, 균핵의 크기는 0.8-3.5(평균 1.8) mm이었다. 균사특유의 clamp connection이 관찰되었다. 분리한 균은 구절초에 대한 실험결과 병원성이 인정되었다. 구절초에 발생한 병징과 분리균의 균학적 특징 및 병원성을 검정한 결과, 이 병을 Sclerotium rolfsii에 의한 구절초 흰비단병으로 명명하고자 한다.

• 식물병연구
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• 제17권2호
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• pp.222-224
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• 2011

경남 창녕군 대합면 양파 재배농가 포장에서 Sclerotium rolfsii에 의한 양파 흰비단병 증상이 발생되었다. 병징은 인경과 줄기 및 잎이 수침상으로 물러지고 썩으면서 시들어 말라 죽고, 병반부와 지제부의 토양 표면에 흰색의 곰팡이가 발생하며 갈색의 작고 둥근 균핵을 형성하였다. 감자한천배지에서 균총은 흰색이며 배양기간이 경과됨에 따라 갈색의 작고 둥근 균핵을 많이 형성하였다. 균핵의 크기는 1-3 mm이며 균사의 폭은 4-9 ${\mu}m$였다. 균사생육과 균핵 형성 적온은 $30^{\circ}C$었다. 균사특유의 clamp connection이 관찰되었다. 양파에서 발생한 병징과 병원균의 균학적 특징, 그리고 ITS rDNA 염기서열 비교분석 결과, 이 병을 S. rolfsii에 의한 양파 흰비단병으로 명명하고자 제안한다.

• The Plant Pathology Journal
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• 제29권4호
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• pp.440-445
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• 2013

Balloon flower (Platycodon grandiflorum) is a kind of mountain herbs whose roots have restorative properties and the cultivating acreage of balloon flower has been steadily increasing in Korea. More frequent rain and high amount of rainfalls as a result of climate changes predisposed balloon flower to the outbreaks of root rot at high-density cultivation area in recent years. Root crowns were usually discolored into brown to blackish brown at first and the infected plants showed slight wilting symptom at early infection stage. Severely infected roots were entirely rotted and whole plants eventually died at late infection stage. The overall disease severities of root rot of balloon flower were quite variable according to the surveyed fields in Jeonnam, Gyeongnam and Jeju Provinces, which ranged from 0.1% to 40%. The root rot occurred more severely at the paddy or clay soils than the sandy soils and their severities were much higher at lowland than upland in the same localty. The disease increased with aging of the balloon flower. The causal fungi were identified as Fusarium solani and F. oxysporum on the basis of their mycological characteristics. The optimum temperature ranges of their mycelial growths was found to be $24^{\circ}C$. The pathogenic characters of F. solani and F. oxysporum treated by artificial wounding inoculation on healthy roots of balloon flower revealed that F. solani was more virulent than F. oxysporum. This study identified the causal agents of root rot of balloon flower as Fusarium solani and F. oxysporum, probably for the first time.