• 한국어병학회지
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• 제26권1호
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• pp.39-44
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• 2013

자연산 다묵장어, Lethenterone reissneri에서 발생한 물곰팡이병의 원인체를 형태학적 및 유전학적 연구를 통하여 동정하였다. 분리균주는 격벽이 없는 균사를 형성하였고, 가늘고 긴 모양의 유주자낭 내에 활발한 운동성을 보이는 유주자가 여러 줄로 배열되었다가 유주자낭의 선단에서 휴면하지 않고 한꺼번에 방출되는 특징을 보였다. 한편 유성생식기관인 조란기와 조정기는 관찰되지 않았다. 또한 분리균주의 ITS sequence를 분석하고 Saprolegnia 속의 다른 분리균주와 유전학적 상관관계를 조사한 결과, S. parasitica가 속해있는 clade I에 분류되는 것을 확인할 수 있었다. 무성생식기관의 형태, 유주자 방출방식 및 ITS sequence의 phylogenetic analysis에 근거하여 자연산 다묵장어에서 관찰된 물곰팡이병의 원인체는 S. parasitica인 것으로 동정되었다.

• 한국식물병리학회지
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• 제14권5호
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• pp.402-407
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• 1998

Phytophthora rot on jujube fruit has occurred at several cultivation areas in Kyung-buk and Kyung-nam provinces. Symptoms consisted of brownish to reddish rot on fruits resulting in early drop or mummification. The causal fungus isolated from infected fruits and adjacent leaf stalks was identified as Phytophthora citricola, which has never been reported in Korea. Sporangia were semi-papillate, noncaducous and highly variable in shapes. Plerotic oospores with paragynous antheridia were abundant is single cultures. Sporangia of two isolates were measured as 38-76$\times$20-40 ${\mu}{\textrm}{m}$ and averaged 51.4$\times$27.0 and 55.6$\times$36.0 ${\mu}{\textrm}{m}$. Oogonia were ranged from 26 to 36 ${\mu}{\textrm}{m}$ and averaged 31.3 and 32.0 ${\mu}{\textrm}{m}$. Colony pattern was slightly radiated with sparse aerial mycelia on common media. Minium, optimum and maximum temperatures for mycelial growth were recorded at 7, 25, and 32$^{\circ}C$, respectively. Among tested media, 10% V8A was the best and $25^{\circ}C$ was better than 15$^{\circ}C$ for oospore formation of the fungus. The jujube isolates of P. citricola were readily differentiated from other closely related species in the genus, namely; P. nicotianae, P. citrophthora, P. cactorum, P. capsici, and P. plalmivora on the basis of PCR-RFLP of r-DNA. The fungus showed strong pathogenicty to jujube, apple, pear, orange, persimmon and eggplant, and relatively weak to citron, tomato, pepper and cucumber. In this study, P. citrocola is firstly identified and jujube fruit rot caused by the fungus is recorded as a new disease in Korea.

• 한국식물병리학회지
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• 제14권5호
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• pp.445-451
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• 1998

A severe Phytophthora rot of strawberry caused by a species of Phytophthora has been widely occurred at major cultivation areas of Kimhae on August in 1997. Incidence of the disease was obtained in the range of 69.2~83.6% in surveyed 4 fields and showed an average of 75.2%. A species of Phytophthora was mostly isolated from the crown of infected strawberry plants and all the isolates were identified as P. nicotianae var. nicotianae (=P. parasitica). The fungus showed strong pathogenicity on strawberry by inoculation test. As a result of the leaf inoculation using mycelial disks of the fungus, both leaves and petioles were darkly browned, and were finally blighted. As a result of the root inoculation of zoospore suspension, both roots and crowns were rotten with dark brown. Although the fungus produced sporangia either on V-8 juice agar medium or liquid medium, the sporangia observed on the liquid medium appeared to be broadly turbinate and noncaducous. Moreover the fungus cultured on the liquid medium often produced sporangia having two papilla. The number of zoospores in sporangia was found to be ranged from 3 or 4 to as many as 20 or 25. In addition, the released zoospore from the sporangium became the cystospore during the prolonged culture of the fungus. The sporangia were measured as av. 49$\times$35 ${\mu}{\textrm}{m}$ with l/b ratio of 1.43. All isolates from crowns were heterothallic and A1 mating type since oospores were abundantly formed on clarified V-8 juice agar by dual culture with P. capsici A2 mating type. Aplerotic oospores were sized 24-26 ${\mu}{\textrm}{m}$. Antheridia were always amphigynous and recoreded an average of 12$\times$10 ${\mu}{\textrm}{m}$. Hyphal swlling were easily observed, and terminal or intercalary chlamydospores were abundantly formed on V-8 juice agar as well as in C/Z solution and sized av. 28.2 ${\mu}{\textrm}{m}$. This is the first report of Phytophthora rot of strawberry in Korea.

• 한국식물병리학회지
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• 제14권5호
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• pp.452-457
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• 1998

Thirty-eight isolates of Phytophthora sp. caused rots on roots and basal stems were collected from five flowering plants from 1992 to 1997 at eight cultivation areas in Korea. All the isolates were identified as P. nicotianae based on following characteristics. The fungus produced markedly papillate, not caducous and ovoid to spherical sporangia, abundant chlamydospores, and small oospores with amphigynous antheridia only when paired with either A1 or A2 mating type. All isolates grew well at 35$^{\circ}C$ and showed distinct arachnoid colony patterns on CMA and PDA. Sizes of sporangia and chlamydospores of five representative isolates from each plant averaged 43-52$\times$30-38 ${\mu}{\textrm}{m}$ and 28 ~34 ${\mu}{\textrm}{m}$. Mating type of the isolates was either A1 or A2, and oogonia and oospores were measured as 28~31 ${\mu}{\textrm}{m}$ and 21~25 ${\mu}{\textrm}{m}$. PCR-RFLP analysis of rDNA of the five isolates resulted that restriction band patterns of the small subunit and ITS regions were identical to a perilla isolate of P. nicotianae, but distinct from P. cactorum and P. capsici. Cross inoculation tests showed that the five isolates had pathogenicity to lily, christmas cactus, anthurium, baby's breath and carnation with different degrees. However, each isolate showed stronger pathogenicity to its corresponding original host than others. Among five lily cultivars Georgia and Quririna were more susceptible than Napoli and others. This is first report of Phytophthora root and stem rot of lily, Christmas cactus, anthurium, baby's breath and monochoria in Korea.

• The Plant Pathology Journal
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• 제20권2호
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• pp.106-109
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• 2004

A leaf blight disease was found on Ailanthus altissiman growing in the Manchon Mountain Park in Daegu city. When isolated, the causal fungus readily formed sex organs, being homothallic. Oogonia were spherical, 19.5-42.9 ${\mu}{\textrm}{m}$ in diameter with an average of 29.4$\pm$4.2 ${\mu}{\textrm}{m}$. Antheridia were amphigynous, round to ovoid, and measured 11.3-15.0 ${\mu}{\textrm}{m}$ long and 12.5-14.5 ${\mu}{\textrm}{m}$ wide. Oospores in the oogonia were spherical, 26.1-29.0 ${\mu}{\textrm}{m}$ in diameter. Sporangia that formed in water were spherical to sub-spherical with a conspicuous papilla and measured 19.5-56.6 ${\times}$ 15.6-44.9 ${\mu}{\textrm}{m}$ with an average of 44.0$\pm$8.7${\times}$32.7$\pm$6.3 ${\mu}{\textrm}{m}$. The mean length/breadth (I/b) ratio was 1.35. Papillae were 3.9-11.7 ${\mu}{\textrm}{m}$l high and 3.9-9.8 ${\mu}{\textrm}{m}$ wide. Sporangia formed slowly on V8 juice agar medium when cultured under fluorescent light at 12-hour alternation. The sporangia that formed on the agar medium were more spherical and measured 26.5-39.0${\times}$23.4-35.1 ${\mu}{\textrm}{m}$ with an average of 33.6$\pm$3.4${\times}$28.2$\pm$3.2 ${\mu}{\textrm}{m}$ and I/b ratio of 1.19. Disease symptom was repro-duced by artificial inoculation of the healthy plants with the isolate. The causal organism was identified as Phyto-phthora boehmeriae on the basis of its morphological characteristics.

• Mycobiology
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• 제32권3호
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• pp.139-147
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• 2004

A severe damping-off disease of bush okra caused by Pythium aphanidermatum, was diagnosed in plastic houses in Der Attia village, 15 km southwest of El-Minia city, Egypt, during the winter of 2001. Bush okra seedlings showed low emergence with bare patches inside the plastic houses. Seedlings that escaped pre-emergence damping-off showed poor growth, stunting and eventually collapsed. Examination of the infected tissues confirmed only Pythium aphanidermatum, showing its typical intercalary antheridia, and lobulate zoosporangia. P. aphanidermatum was shown to be pathogenic on bush okra under pot and field experiments. Bacteria making inhibition zones against the damping-off fungus P. aphanidermatum were selected. Agar discs from rhizosphere soil of bush okra containing colonies were transferred onto agar plate culture of P. aphanidermatum. After 2 days of incubation, colonies producing clear zones of non-Pythium growth were readily detected. The two bacteria with the largest inhibition zones were identified as Pseudomonas fluorescens. Bush okra emergence(%) in both pot and plastic houses experiments indicated that disease control could be obtained by applying P. fluorescens to the soil or coating the bacteria to the bush okra seeds before sowing. In the plastic houses, application of the bacteria onto Pythium-infested soil and sowing bush okra seeds dressed with bacteria gave 100% emergence. In addition, This was the first reported disease of bush okra by this oomycete in Egypt.

• 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.

• 식물병연구
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• 제9권1호
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• pp.32-35
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• 2003

1999년 강원도 평창의 고랭지 감자 재배지에서 감자 홍색부패병이 발견된 이후 2001년과 2002년에는 전남 보성의 감자 재배지에서도 발생이 확인되었고 발병이 심한 지역에서는 약 5%정도의 이병율을 보였다. 병든 감자의 주요 병징은 괴경 외부가 연갈색으로 변색되어 부패증상이 나타나고 피목과 눈이 흑갈색으로 변화되어 건전 부위와 이병 부위가 쉽게 구분되었다. 또한 괴경 내부는 삶은 감자처럼 스폰지 형태로 변하고 냄새가 없었으며 괴경 절단면은 공기 중에 노출된지 30분 이후에 핑크색으로 변색되는 특징을 확인할 수 있었다. 균사는 배지에 따라 방사형, 장미꽃 또는 솜털 모양으로 특징적인 생육을 하였고, 균사생육온도는 5.0~3$0^{\circ}C$범위이고 최적온도는 $25^{\circ}C$였다. 유주자낭은 유두돌기 없이 선단 부위가 평편하고, 계란 또는 서양배 모양의 다양한 형태로 크기는 41.3~69.6$\times$26.8~47.4(평균 55.5$\times$37.1) $\mu\textrm{m}$이었다. 병원균은 동종생식에 의하여 유성생식기관을 형성하여 동일 배지에서 배양초기부터 엷은 황색의 난포자를 대량으로 생산하였고 장난기 형태는 구형으로 크기가 30$\times$46 $\mu\textrm{m}$이었고, 장정기는 저착성이고 형태가 신장된 타원형으로 크기가 13$\times$14 $\mu\textrm{m}$이었다. 이들 병원균의 배양적, 형태적 특성에 의거, Phytophthora erythroseptica에 의한 감자 홍색부패병으로 동정되어 국내에서 처음으로 보고한다.