• Mycobiology
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• 제43권2호
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• pp.170-173
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• 2015

Herein, we report the first occurrence of web blight of rosemary caused by Rhizoctonia solani AG-1-IB in Gangneung, Gangwon Province, Korea, in August 2014. The leaf tissues of infected rosemary plants were blighted and white mycelial growth was seen on the stems. The fungus was isolated from diseased leaf tissue and cultured on potato dextrose agar for identification. The young hyphae had acute angular branching near the distal septum of the multinucleate cells and mature hyphal branches formed at an approximately $90^{\circ}$ angle. This is morphologically identical to R. solani AG-1-IB, as per previous reports. rDNA-ITS sequences of the fungus were homologous to those of R. solani AG-1-IB isolates in the GenBank database with a similarity percentage of 99%, thereby confirming the identity of the causative agent of the disease. Pathogenicity of the fungus in rosemary plants was also confirmed by Koch's postulates.

• 한국환경농학회지
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• 제28권4호
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• pp.435-441
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• 2009

In the present study, we analyzed the defensin protein deduced from Korean radish (Raphanus sativus L.) seeds.To express the genes in E. coli, we constructed a recombinant expression vector with a defensin gene, named rKRs-AFP gene isolated from Korean radish seeds. Over expressed rKRs-AFP proteins was separated by SDS-PAGE to determine the purity, and protein concentration was determined by the Bradford method. Antifungal activity was assessed by disk assay method against the tested fungi. As a result, when 500 mL of cell culture were disrupted by sonicator, 32.5 mg total proteins were obtained. The purified protein showed a single band on SDS-PAGE with estimated molecular weight about 6 KDa, consistent with the molecular mass calculated from the deduced amino acid sequence. The purified rKRs-AFP protein showed remarkable antifungal activities against several fungi including Aspergillus niger, Botrytis cinerea causing the gray mold disease, and Candida albicans. In field tests using the purified rKRs-AFP protein, the protein showed the reducing activity of disease spot and the mitigating effect of spreading of disease like agrichemicals. The immuno-assay of rKRs-AFP protein showed that the purified protein entirely accumulated at B. cinerea cytoplasm through the hyphal septa shown by fluorescence imaging. There was no fluorescence inside the cell, when the hypha was incubated without the protein. These all results indicate that the recombinant rKRs-AFP proteins can be utilized as a potential antifungal drug to control harmful plant fungal pathogens.

• 한국수산과학회지
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• 제14권1호
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• pp.37-42
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• 1981

무지개송어의 자어기에 Ichthyophonus sp.인 곰팡이가 감염되어 있는 것을 발견하고 그 후 계속 사육된 어군을 6개월마다 채집하여 병리조직학적으로 관찰하였다. 1. 무지개송어의 치어에는 Ichthyophonus sp.가 전신적으로 감염되어 있었으며, 2년생인 어류에는 Ichthyophonus sp.를 둘러싼 육아종이 많이 발생되고 있었다. 2. 각 조직내에 보이는 Ichthyophonus sp.는 다핵구상체가 가장 많았으며, 때로는 발아중인것과 계장체도 나타났다. 3. Ichthyophonus sp.의 cyst 주변에는 대단핵세포가 모인 번식성 염증를 볼 수 있었다.

• 한국균학회지
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• 제45권4호
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• pp.381-385
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• 2017

Sclerotinia rot was observed on Ixeridium dentatum cultivated as a succeeding crop in a garlic field in Seosan-si, Korea during the growing season in 2016 and 2017. Symptoms progressed from the initial irregular, water-soaked spots on main stems to wilting and eventually to plant death. White, cottony mycelia and black, irregular sclerotia formed on the basal stem and on soil surfaces. The optimal temperature of hyphal growth and sclerotia germination were $20^{\circ}C$ and $25^{\circ}C$, respectively. Sequence analysis of the internal transcribed spacer (ITS) regions revealed that the three strains isolated from Ixeridium dentatum are grouped with Sclerotinia sclerotiorum. Three strains were identified as Sclerotinia sclerotiorum based on morphological features, ITS sequence, and pathogenicity test. To the best of our knowledge, this work is the first report of Sclerotinia sclerotiorum causing sclerotinia rot on Ixeridium dentatum in Korea.

• The Plant Pathology Journal
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• 제24권1호
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• pp.90-92
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• 2008

In 2007, a bulb rot of Allium victorialis var. platyphyllum Makino caused by Sclerotium rolfsii occurred sporadically in a herb farm at Gyeongsangnam-do, Korea. The symptom initiated with water-soaking lesion and progressed into bulb rot and wilt of a whole plant. Severely infected plants were blighted and killed eventually. White mycelial mats appeared on the lesion at early stage and a number of sclerotia were formed on the bulb. The sclerotia were spherical, $1{\sim}3 mm$ and white to brown. The optimum temperature for the growth and sclerotia formation was $30^{\circ}C$ on PDA. The hyphal width was measured $4-9{\mu}m$. The typical clamp connections were observed on PDA. Based on the symptom, mycological characteristics and pathogenicity to the host plant, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the bulb rot of A. victorialis var. platyphyllum caused by S. rolfsii in Korea.

• 식물병연구
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• 제26권2호
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• pp.109-115
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• 2020

A disease causing leaf blight and vine rot was recognized on kudzu plants (Pueraria lobata) in Korea since 1991. A species of Phytophthora has been repeatedly isolated from the infected leaves. Identification in species level of the Phytophthora sp. remained unsolved. An isolate, KACC 47616 originally collected from Manchon Park in Daegu, has been kept in our laboratory. In 2013, three new isolates, KACC 47617 and KACC 47618 from Yeongyang and KACC 47619 from Gunwi in Gyeongbuk province, were collected and examined to classify up to species level by characterizing morphology, response to temperature and phylogenetic relationship. On the basis of morphological characters such as the nature of hyphal swelling, sporangia and sex organs, absence of chlamydospore production, optimum temperature for mycelial growth, and internal transcribed spacer rDNA and cytochrome oxidase subunit 1 sequence analysis of the pathogen, the causal fungus of kudzu plant was identified as Phytophthora asiatica.

• 한국균학회지
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• 제36권2호
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• pp.203-205
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• 2008

2006년에서 2008년까지 진주에서 재배중인 페튜니아에서 병이 발생하였다. 병징은 줄기와 잎이 수침상으로 물러지고 썩으면서 갈색으로 변하며 시들어 말라 죽었다. 줄기, 지제부 및 토양 표면에 솜털모양의 흰색 균사체가 생기고 $1{\sim}3\;mm$ 크기의 둥근 갈색 균핵을 많이 형성하였다. PDA배지 상에서 병원균의 균사 폭은 $4{\sim}8\;{\mu}m$이며 clamp connection이 형성되었고 균사생육과 균핵형성 적온은 $30^{\circ}C$이었다. 페튜니아에서 발생한 병징과 병원균의 균학적 특징 및 병원성을 기초로 본 병을 Sclerotium rolfsii Saccardo에 의한 페튜니아 흰비단병으로 명명하고자 제안한다.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.209-214
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• 1992

Serratia marcescens co-cultured with various phytopathogenic fungi, including Rhizopus stolonifer, Helminthosporium allii, Pyricularia oryzae, Fusarium oxysporium and Collectothricom cassiicola, in an LB- agar medium containing 1.5% swollen chitin, significantly inhibitied fungal growth. Fungal hyphae grew rapidly outward from the culture dish center, but the hyphal extensions of the pathogenic fungi were significantly inhibited in a perimetric contact area with S. marcescens. This was especially evident in pathogenic fungi which have a high chitin content in their cell walls. The extracellular chitinase activities of S. marcescens were increased seven fold by the addition of 1.5% swollen chitin to the LB-broth, compared to chitinase activities in a culture medium without chitin. The type of induction was dependent on the various forms of chitin used. When the culture supernatant of S. marcescens or the chitinases of Streptomyces griceus purchased from Sigma Chemical Co., were incubated with the mycelium of F. oxysporium, the mycelium gradually burst as cultivation time progressed and completely lysed after incubation for 2 days. On the other hand, E. coli extract did not hydrolyze the F. oxysporium mycelium at all. These data showed that the chitinolytic activities of S. marcescens play important roles in the biochemical control of phytopathogenic fungi.

• 한국어병학회지
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• 제2권2호
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• pp.71-74
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• 1989

1. 돌돔의 Ichthyophonus증(症)을 병리조직학적(病理組織學的)으로 검토(檢討)하였다. 2. Ichthyophonus sp.의 다핵구상체(多核球狀體)는 돌돔의 위(胃), 장(腸), 간(肝), 비장(脾臟), 신장(腎臟), 심장(心臟)에서 관찰(觀察)할 수 있었다. 3. Ichthyophonus sp.에 의한 돌돔의 염증성(炎症性) 반응(反應)은 대단핵세포(大單核細胞)의 번식성염증(繁殖性炎症)의 특징이었다. 4. 다핵구상체(多核球狀體)를 포함(包含)한 육아종(肉芽腫)이 많이 형성(形成)되며, 전체적(全體的)으로 많이 번식(繁殖)하고 있었다.

• 한국균학회지
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• 제13권2호
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• pp.79-82
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• 1985

식용으로 재배면적이 증가하고 있는 느타리버섯과 사철느타리버섯의 유전연구와 균주개 발을 위하여 원형질체의 재생 및 환원에 관한 실험 결과를 요약하면 다음과 같다. 1. 느타리버섯의 원형질체 재생에 알맞는 삼투압 조절제는 0.6 M KCl과 0.6 M Sucrose였으며, 균사의 생장을 촉진하는 amino acid와 vitamin을 혼합한 배지에서 원형질체 환원율이 약 5배로 증가하였다. 2. 삼투압 조절제가 첨가된 배지에서 재생후 2일부터 원형질체가 재생하여 $5{\sim}10$일에 균총을 육안으로 확인하였으며, 환원율이 $0.24{\sim}3.19%$로 사철느타리버섯과 wild type이 느타리버섯과 영양요구성 균주보다 환원율이 다소 높았다.