• 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.

• 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.

• 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.

• 한국식물병리학회지
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• 제14권5호
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• pp.519-525
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• 1998

Intraspecific genetic diversity of Korean isolates of Phytophthora drechsleri was investigated based on PCR-RFLP of rDNA along with closely related species in the genus; P. cryptogea, P. melonis, P. erythroseptica, P. cinnamomi, P. cambivora and P. cactorum. Gene regions of nuclear small subunit and internal transcribed spacer (ITS) in rDNA were amplified with polymerase chain reaction and digested with 9 restriction enzymes. Phytophthora species was readily differentiated from each other based on the digestion patterns, however, P. cryptogea was not separable from some isolates of P. drechsleri. Twenty one isolates of P. drechsleri originated from 15 host plants were divided into three distinct groups designated as PdG1, PdG2 and PdG3, respectively. Four isolates in PdG1 were originated from green vegetables and tomato and nine isolates in PdG2 were mainly isolated from medicinal plants. The two groups showed 95.3% homology and four isolates of P. cyptogea came under the groups. However, Eight isolates in PdG3 collected from cucurbits were clearly differentiated from those of PdG1 and PdG2 by 66.5% homology, but completely matched with a Taiwan isolate of P. melonis. Results indicated that three distinct groups exist in Korean isolates of P. drechleri and each group has host preference. In addition, reclassification of the cucurbits isolates are reserved because of their distinct genetic characters from other intraspecific groups in P. drechsleri.

• The Plant Pathology Journal
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• 제15권1호
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• pp.28-33
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• 1999

Phytophthora root rot of Chniese cabbage and spinach is reported for the first time in Korea. The diseases ocurred at Yangju, Seosan and Yeocheon in Korea from 1995 through 1998, mainly in lowland and submerged areas. Symptoms consisted of stunt, yellows, wilt and eventual death due to root rot. Fourteen isolates collected from naturally infected plants were all identified as P. drechsleri based on mycological characteristics. PCR-RFLP analysis of rDNA of the isolates confirmed the above result, since the restriction band patterns of the small subunit and internal transcribed spacers were identical to P. drechsleri and P. cryptogea, but distinct from closely related species of P. erythroseptica, P. cambivora, P. sojae and P. megasperma. The pathogen showed strong pathogenicity to Chinese cabbage, moderate to spinach, radish, cabbage and tomato, and weak or none to brown mustard, kale, chicory and pepper in pathogenicity tests.