• 식물병연구
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• 제8권1호
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• pp.41-44
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• 2002

＇97∼＇98년에 경북지역의 대구와 경산, 군위, 영천, 청도등 대추과원에서 과실에 역병이 발생되었다. 병징은 과실이 적갈색의 반점이 생기며 심하면 미이라가 되고, 말라서 조기낙과되며 엽병과 신초에도 마름증상을 나타내기도 했다. 이병과에서 2종의 역병균이 검출되었는데 총 18개 역병균중 6균주는 P. nicotiamae로 동정되었고, 나머지 12균주는 P. palmivora로 동정되었다. P. nicotianae는 유두돌기가 뚜렷하고 비탈락성인 구형 혹은 난형의 유주자낭과 다량의 후막포자를 형성하였으며 유성생식형은 자웅이주로 A1 mating type이 조사되었다. P. palmivora는 유주자낭이 유두돌기가 뚜렷하고 탈락성이며 장타원형 혹은 난형, 구형 등이었고, 다량의 후막포자를 형성하였으며 유성생식형은 자웅이주로 A1 mating type이 조사되었다. 2종의 역병균 모두 대추와 배에 강한 병원성을 나타내었으나. 사과에는 병원성이 없었다. P. nicotiamae 와 P. palmivora에 의한 대추 역병은 국내에서 최초로 보고되는 것이다.

• Mycobiology
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• 제43권1호
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• pp.63-70
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• 2015

Phytophthora diseases have become a major impediment in the citrus production in Thailand. In this study, an isolate of Phytophthora denominated as PHY02 was proven to be causal pathogen of root rot of Pomelo (Citrus maxima) in Thailand. The isolate PHY02 was morphologically characterized and identified as Phytophthora palmivora based on molecular analysis of an internal transcribed spacer rDNA sequence. This work also presents in vitro evaluations of the capacities of Chaetomium spp. to control the P. palmivora PHY02. As antagonists, Chaetomium globosum CG05, Chaetomium cupreum CC3003, Chaetomium lucknowense CL01 inhibited 50~61% mycelial growth, degraded mycelia and reduced 92~99% sporangial production of P. palmivora PHY02 in bi-culture test after 30 days. Fungal metabolites from Chaetomium spp. were tested against PHY02. Results showed that, methanol extract of C. globosum CG05 expressed strongest inhibitory effects on mycelial growth and sporangium formation of P. palmivora PHY02 with effective dose ED50 values of $26.5{\mu}g/mL$ and $2.3{\mu}g/mL$, respectively. It is interesting that C. lucknowense is reported for the first time as an effective antagonist against a species of Phytophthora.

• 한국식물병리학회지
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• 제14권6호
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• pp.725-728
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• 1998

Phytophthora crown rot of cymbidium was observed in Cheju island since June of 1996. The disease initiated at the basal portion of infected plant progressed upward to lower leaves. Soon after distinct water-soaking lesions appeared on lower leaves, the plant was wilted, blighted and died. Four orchid farms at Sogwipo out of 16 surveyed in the island were infected by the disease estimating 5~20% infection rates. The causal fungus was identified as P. palmivora based on following distinguishing characteristics. All isolates were heterothallic as A1 types and readily produced chlamydospores with cultural age. Sporangia were conspicuous papillate, ellipsoidal to ovoid, highly deciduous with short pedicels ca. 3~4 ${\mu}{\textrm}{m}$. Koch's rules were satisfied by a pathogenicity test and re-isolation of the fungus from inoculated plants. The pathogen has never been reported in Cheju island previously and its firstly recorded as the cause of Phytophthora crown rot of cymbidium in Korea.

• The Plant Pathology Journal
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• 제35권1호
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• pp.19-31
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• 2019

Bud rot (BR) is the most devastating disease affecting oil palm (Elaeis guineensis) crops in Colombia. Its causal agent, Phytophthora palmivora, initiates the infection in immature oil palm leaflets producing necrotic lesions, followed by colonization of opportunistic necrotrophs, which increases disease damage. To improve the characterization of the disease, we transformed P. palmivora using Agrobacterium tumefaciens-mediated transformation (ATMT) to include the fluorescent proteins CFP-SKL (peroxisomal localization), eGFP and mRFP1 (cytoplasmic localization). The stability of some transformants was confirmed by Southern blot analysis and single zoospore cultures; additionally, virulence and in vitro growth were compared to the wild-type isolate to select transformants with the greatest resemblance to the WT isolate. GFP-tagged P. palmivora was useful to identify all of the infective structures that are commonly formed by hemibiotrophic oomycetes, including apoplastic colonization and haustorium formation. Finally, we detected cell death responses associated with immature oil palm tissues that showed reduced susceptibility to P. palmivora infection, indicating that these tissues could exhibit age-related resistance. The aim of this research is to improve the characterization of the initial disease stages and generate cell biology tools that may be useful for developing methodologies for early identification of oil palm materials resistant or susceptible to BR.

• Mycobiology
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• 제46권2호
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• pp.129-137
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• 2018

Black rot disease in orchids is caused by the water mold Phytophthora palmivora. To gain better biocontrol performance, several factors affecting growth and antifungal substance production by Pseudomonas aeruginosa RS1 were verified. These factors include type and pH of media, temperature, and time for antifungal production. The results showed that the best conditions for P. aeruginosa RS1 to produce the active compounds was cultivating the bacteria in Luria-Bertani medium at pH 7.0 for 21 h at $37^{\circ}C$. The culture filtrate was subjected to stepwise ammonium sulfate precipitation. The precipitated proteins from the 40% to 80% fraction showed antifungal activity and were further purified by column chromatography. The eluted proteins from fractions 9-10 and 33-34 had the highest antifungal activity at about 75% and 82% inhibition, respectively. SDS-PAGE revealed that the 9-10 fraction contained mixed proteins with molecular weights of 54 kDa, 32 kDa, and 20 kDa, while the 33-34 fraction contained mixed proteins with molecular weights of 40 kDa, 32 kDa, and 29 kDa. Each band of the proteins was analyzed by LC/MS to identify the protein. The result from Spectrum Modeler indicated that these proteins were closed similarly to three groups of the following proteins; catalase, chitin binding protein, and protease. Morphological study under scanning electron microscopy demonstrated that the partially purified proteins from P. aeruginosa RS1 caused abnormal growth and hypha elongation in P. palmivora. The bacteria and/or these proteins may be useful for controlling black rot disease caused by P. palmivora in orchid orchards.

• 식물병연구
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• 제10권2호
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• pp.100-104
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• 2004

대구시 황금동 주택가에 자라는 아주까리에 발생한 역병(잎마름병)에서 2종의 Phytophthora 균이 분리되었다. 그 하나는 유두돌기가 뚜렷하고, 비탈락성이며, 난형 내지 서양 배 모양의 유주자낭을 형성하고, 그 크기는 31.2-58.5${\times}$25.4-44.1 $\mu\textrm{m}$의 범위에 평균 46.4$\pm$6.5${\times}$35.9$\pm$4.7 $\mu\textrm{m}$, 이주성(Heterothallic)으로서 장란기는 둥글고, 직경 22.5-35.0$\mu\textrm{m}$ 범위에 평균 30$\pm$3.3$\mu\textrm{m}$,그 안의 난포자는 충만형이었으며, 직경 18.8-30.0$\mu\textrm{m}$ 범위에 평균 25.4$\pm$2.8$\mu\textrm{m}$ 이었다. 장정기는 장란기에 저착하였다. 이 종은 Phytophthora nicotianae로 동정되었다. 다른 하나의 종은 유두돌기가 뚜렷하고, 탈락성이며, 난형 내지 타원형, 기부에 자루가 붙어있는 유주자낭을 형성하였으며, 그 크기는 21.5-54.6${\times}$l7.6-34.3$\mu\textrm{m}$ 범위에 41.7$\pm$7.1${\times}$28.4$\pm$4.0$\mu\textrm{m}$, 이주성이었으며, 장란기는 구형, 직경 21.3-26.8$\mu\textrm{m}$ 범위에 평균 23.0$\pm$1.6$\mu\textrm{m}$, 난포자는 충만형, 직경 17.5-23.8$\mu\textrm{m}$ 범위에 평균 20.2$\pm$1.8$\mu\textrm{m}$, 장정기는 저착하였다. 이 종은 P. palmivora (Butler) Butler로 동정되었다. 2종 모두 후막포자를 형성하였다. 이들 2종 Phytophthora 균은 아주까리 유묘의 잎에 강한 병원성을 나타내었다. 이들 2종에 의한 아주까리 역병의 발생은 외국에서는 이미 보고되어 있으나 국내에서는 처음이다.

• The Plant Pathology Journal
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• 제15권4호
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• pp.228-235
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• 1999

Genetic diversity of ninety-five Korean isolates of Phytophthora was investigated on the basis of PCR-RFLP of ribosomal DNA. The isolates were previously identified as following fifteen species by mycological and cultural characteristics; P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamoni, P. citricola, P. citrophthora, P. cryptogea, P. drechsleri, P. erythroseptica, P. infestans, P. megasperma, P. nicotianae, P. palmivora and P. sojae. The regions of small subunit (SSU) and internal transcribed spacer (ITS) of rDNA were amplified with primer pair, NS1 and ITS4, by polymerase chain reaction (PCR) and digested with nine restriction enzymes. P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamomi, P. citricola, P. citrphthora, P. infestans, P. nicotianae and P. palmivora showed specific band patterns for each species. However, P. sojae and P. erythroseptica presented identical band patterns and P. cryptogea, P. drechsleri and P. megasperma were divided into six groups, which were not compatible with delineation of the species. A group originated from cucurbits showed distinct band patterns from other groups, but the other five groups were closely related within 96.0% similarity, forming one complex group. Consequently, Korean isolates of Phytophthora were divided into thirteen genetic groups and each group was readily differentiated by comparing digestion patterns of AvaII, HaeIII, MboI, HhaI and MspI. Therefore, PCR-RFLP of rDNA using the five enzymes can be used to differentiate or identify the Phytophthora species reported in Korea so far.

• 한국균학회지
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• 제38권1호
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• pp.40-47
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• 2010

Phytophthora 속의 핵(ypt 유전자, rDNA-IGS region) 및 미토콘드리아(Cox 유전자, $\beta$-tubline 유전자, EF1A 유전자) 내에 존재하는 5가지 유전자 영역을 이용하여 국내 Phytophthora 속 14종의 유전적 다양성을 분석하였다. 국내 Phytophthora 속은 외국의 Phytophthora 속과 동일한 clade를 형성하였으나, 외국의 Phytophthora 속과 마찬가지로 본 연구에서도 분자생물학적 분류와 형태학적 분류와는 연관성을 찾기 어려웠다. 기존에 보고된 국내 P. palmivora KACC 40167 균주의 그룹이 국내에서 보고된 분류체계와 일치하지 않아 추후 재검토가 필요하였다. P. cryptogea-P. drechsleri complex group 내 국내 P. cryptogea KACC 40161 균주와 P. drechsleri KACC 40195 균주는 서로 94% 이상의 유사도를 보여 재동정이 필요하였으며, P. parasitica와 P. nicotianae간의 유사도가 99% 이상으로 나타나 이 두 종간에 통일된 종명이 요구된다. 또한 현재 분자계통학상 5그룹으로 구분된 국내 Phytophthora 속을 외국균주들과 비교하여 10개의 그룹으로 새롭게 재분류하였다. 이러한 결과들은 국내 Phytophthora 속의 유전적 다양성 연구를 위해 유용한 자료가 될 것이다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1999년도 정기총회 및 춘계 학술발표회
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• pp.25.1-25
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• 1999

• The Plant Pathology Journal
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• 제16권1호
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• pp.29-35
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• 2000

The internal transcribed spacer regions (ITS I, 5.8S and ITS II) of the ribosomal DNAs were amplified from Korean isolates of Phytophthora spp. and sequenced to characterize them. Sequences from 33 isolates previously identified as P. boehmeriae, P. cactprum, P. cambivora, P. capsici, P. cinnamomi, P. erythroseptica, P. infestans, P. megasperma, P. melonis, P. nicotianae, P. palmivora and P. sojae were compared with published sequences, and a phylogenetic tree was produced. All isolates belonging to 10 species, P. cactorum, P. cambivora, P. capsici, P. cinnamomi P. citricola, P. infestans, P. nicotianae, P. palmivora and P. sojae were clearly clustered into published isolates of each species above 97% bootstrap value. Cucurbits isolates of Phytophthora previously identified as either P. melonis or P. drechsleri showed distinct evolutionary lineages from the P. megasperma was closely related to isolates of P. cryptogea-P. drechsleri showed distinct evolutionary lineages from the P. cryptogea-P. drechsleri complex group, indicating that P. melonis is a valid species. A Korean isolate of P. megasperma was closely related to isolates of P. erythroseptica showed distant genetic relationship with published isolates of P. erythroseptica (CBS 956.87). It is probable that the two Korean isolates could be genetically different from foreign isolates or misidentified. A grouping of species according to ITS sequence divergence matched, to some degree, the broad classification based on type of papilla. However, a separation of semi-papillate species and papillate species was not wvident in this study.