• 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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• 제14권6호
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• pp.646-650
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• 1998

Mycological characteristics of Phytophthora nicotianae var. nicotianae SPC10 (A1 type) causing Phytophthora rot of strawberry and the resistances of 11 strawberry cultivars against the pathogen were examined. Optimum temperature for the mycelial growth of the pathogen was obtained in the range of 30~35$^{\circ}C$, and the growth was completely stopped under 13$^{\circ}C$ or over 42$^{\circ}C$. Aerial mycelia were abundant on oatmeal agar (OMA), V-8 juice agar (V8A) and lima bean agar (LBA) medium, although there were slight differences, however, on cornmeal agar (CMA) medium, it was a shape of stellate without aerial mycelia. The colony shape on potato dextrose agar (PDA) medium was rough and irregular whereas the mycelial growth was slow, and some aerial mycelia were only produced in the middle of PDA medium. Optimum temperature for sporangial formation was 3$0^{\circ}C$, and zoospores were mostly released at $25^{\circ}C$ from the sporangia. Sporangia were more produced in C/Z solution with pH 5. 0~6.$0^{\circ}C$ than sterilized distilled water (DSW) and distilled water (DW), and zoospores were also released much more than other solutions. Eleven strawberry cultivars such as Reiko, Hokowase, Eyeberry, Akaneko, Sistakara, Toyonoka, Nyoho, Sulhong, Suhong, Myhong and Wonkyo #3104 revealed the disease incidence up to 88.9~100% by the leaf inoculation with mycelial disk. However, Nyoho and Suhong showed higher level of resistance against the pathogen by root inoculation.

• 한국식물병리학회지
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• 제14권5호
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• pp.408-412
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• 1998

In order to illustrate the role of conidia of Mycosphaerella nawae as a secondary inoculum in nature, pseudothecial development on persimmon leaves was investigated microscopically. The fungal ascospores have been believed as the primary or only inoculum source in nature, however, pseudothecia were readily formed on persimmon leaves infected naturally and artificially by conidia. The pseudothecia of M. nawae were found to form in the tissues of infected leaves while the leaves were still hanging on the trees. The size of pseudothecia were approximately 51.0~122.4$\times$51.0~112.2 ${\mu}{\textrm}{m}$ (82.8 $\times$72.5 ${\mu}{\textrm}{m}$in average), the shapes were spherical, ovoid or occidental pear type. The sizes of asci were approximately 30.6~61.2$\times$8.2~10.2 ${\mu}{\textrm}{m}$(46.6$\times$9.4 ${\mu}{\textrm}{m}$ in average) and the shapes were cylinder or banana. The ascospores were mostly spindle type, and the sizes were 10.2~12.2$\times$3.1~4.1 ${\mu}{\textrm}{m}$ (11.4$\times$3.2 ${\mu}{\textrm}{m}$ in average)-like. The pseudothecial formation was initiated before defoliation and morphological characteristics of the pseudothecia, ascus and ascospores on the infected leaves were fully illustrated in this study. Results indicated that conidia of M. nawae induce circular leaf spot of persimmon as much as ascospores, and might play an important role of the disease epidemics in nature.

• 한국자원식물학회지
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• 제12권4호
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• pp.260-268
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• 1999

황련(Coptis japonica)의 추출액을 공시하여 Phytophthora capsici, Fusarium oxysporum, Colletotrichum dematium, C. truncatum, Botrytis cinerea, Botryosphaeria dothidea과 Alternaria porri에 대해 항균 활성 검정, 몇가지 작물에 대한 병해 방제 효과를 조사하고 항균 활성 물질을 동정하였다. 황련 추출액은 P. capsici, F. oxysporum, C. dematium, B. cinerea, B. dothidea 및 A. porri에 대해서 항균력이 우수하였다. Methanol을 용매로 추출하여 분리된 물질과 berberine-Cl 표준품의 항균활성을 비교할 때, 황련추출액으로부터 분리된 물질은 표준품 berberine-Cl과 비슷하게 항균력을 나타내었다. 황련 추출액은 고추 역병(83.3%), 참깨 모잘록병 (92.0%) 및 파 검은무늬병(87.5%)에 대해서 방제효과가 인정되었다. 고추 잎과 과실, 파 잎 및 딸기 과실에는 약해가 나타나지 않았으나 고농도에서는 고추 및 참깨의 발아를 억제하거나 유근의 신장을 억제하는 것으로 나타났다. Methanol로 추출한 황련 추출액으로부터 황색 분말 4.24g/100g을 얻을 수 있었다. 이들 물질을 HPLC로 분석한 결과 항균성을 나타내는 물질은 berberine-Cl로 동정되었다.

• The Plant Pathology Journal
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• 제35권3호
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• pp.243-256
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• 2019

Field surveys for Plum pox virus (PPV) infection were conducted in stone fruit orchards all over Bulgaria. In total, 1168 out of 3020 leaf samples from cultivated Prunus spp. and wildly growing P. cerasifera trees reacted positive for PPV in DASI-ELISA with the universal monoclonal antibody (MAb) 5B. Further ELISA analyses showed that 987 and 127 isolates belonged to PPV-M and PPV-D serotypes, respectively. The plum and P. cerasifera showed 82.0% and 50.5% levels of infection, respectively followed by the peach (40.0%) and the apricot (32.0%). Five hundred fifty one PPV isolates were further typed by IC-RT-PCR with PPV-Rec, -M and -D-specific primers, targeting (Cter)NIb-(Nter) CP genome region, as 125 isolates were sequenced. The results revealed the presence of PPV-Rec, PPV-M and PPV-D and mixed infections of these strains. PPV-Rec was the most prevalent strain (49.0%), followed by PPV-M (40.1%), while PPV-D was the less spread strain (8.2%). PPV-Rec was the most common strain in plums, including the eight "old-aged" trees from the region of the first Sharka discovery. PPV-M was the most prevalent strain in peach and apricot. Phylogenetic analyses on (Cter)NIb-(Nter)CP of the isolates were performed. PPV-Rec isolates formed a homogeneous group, while PPV-M isolates split into PPV-Ma and PPV-Mb subgroups. Five separated clades were formed by the analyzed PPV-D isolates. Nucleotide sequences of the partial CP coding region of the analyzed isolates revealed a slightly higher intra-strain genetic variability in PPV-Rec and PPV-M isolates, while that of PPV-D strain isolates was higher from the reported for these strains.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.67.2-68
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• 2003

A rice cultivar, Taebaegbyeo, is highly resistant to rice blast and moderately resistant to bacterial leaf blight (BLB) caused by Magnaporthe grisea and Xanthomonas oryzae pv. oryzae, respectively. To study the rice disease resistance mechanism, we generated rice deletion M3 mutants by gamma-ray irradiation. Blast and BLB responses of 16,000 M3 mutants were screened by inoculating mixtures of 4 races (KJ-201, H-1113a, KI-313, KI-409) of M. grisea and 3 Korean races of X. oryzae pv. oryzae. We selected so far 21 M3 mutants of Taebaegbyeo showing high susceptibility to the diseases. One of the mutants, KCT-6417, was susceptible to KI-1113a race of M. grisea, suggesting the deletion of a race-specific blast resistance gene in the mutant. To isolate rice genes involved in blast resistance and defense response, we take a PCR-based suppression subtractive hybridization approach using cDNAs of blast-inoculated wild type and the KCT-6417 as a tester and a driver, respectively. Genes specifically expressed in the wild type will be presented. The selected genes would give us a clue to understand mechanism for the race specific resistance and defense responses against M. grisea H-1113a in Taebaegbyeo.

• The Plant Pathology Journal
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• 제39권2호
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• pp.191-206
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• 2023

Ground cherry (Physalis pubescens) is the most prominent species in the Solanaceae family due to its nutritional content, and prospective health advantages. It is grown all over the world, but notably in northern China. In 2019 firstly bacterial leaf spot (BLS) disease was identified on P. pubescens in China that caused by both BLS pathogens Xanthomonas euvesicatoria pv. euvesicatoria resulted in substantial monetary losses. Here, we compared whole genome sequences of X. euvesicatoria to other Xanthomonas species that caused BLS diseases for high similarities and dissimilarities in genomic sequences through average nucleotide identity (ANI) and BLAST comparison. Molecular techniques and phylogenetic trees were adopted to detect X. euvesicatoria on P. pubescens using recQ, hrpB1, and hrpB2 genes for efficient and precise identification. For rapid molecular detection of X. euvesicatoria, loop-mediated isothermal amplification, polymerase chain reaction (PCR), and real-time PCR techniques were used. Whole genome comparison results showed that the genome of X. euvesicatoria was more closely relative to X. perforans than X. vesicatoria, and X. gardneri with 98%, 84%, and 86% ANI, respectively. All infected leaves of P. pubescens found positive amplification, and negative controls did not show amplification. The findings of evolutionary history revealed that isolated strains XeC10RQ, XeH9RQ, XeA10RQ, and XeB10RQ that originated from China were closely relative and highly homologous to the X. euvesicatoria. This research provides information to researchers on genomic variation in BLS pathogens, and further molecular evolution and identification of X. euvesicatoria using the unique target recQ gene through advance molecular approaches.

• 식물병연구
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• 제26권4호
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• pp.272-278
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• 2020

2019년 Paratylenchus projectus에 의한 심각한 상추 피해를 국내 처음으로 보고하였다. 상추 시설재배지에서 P. projectus 밀도를 낮출 수 있는 고소득 윤작작물을 탐색하고자 십자화과(Brassicaceae)에서 6종; 갓(leaf mustard, Brassica juncea), 경수채(kyona, B. rapa subsp. nipposinica), 브로콜리(broccoli, B. oleracea var. italica), 청경채(bok choy, B. rapa subsp. chinensis), 케일(kale, B. oleracea var. viridis), 콜라비(kohlrabi, B. oleracea var. gongylodes), 국화과(Asteraceae)의 2종; 엔다이브(endive, Cichorium endivia), 치커리(chicory, C. intybus), 매꽃과(Convolvulaceae)의 1종인 공심채(morning glory, Ipomoea aquatica) 등 총 9종을 윤작시험에 사용하였다. 각 엽채류를 직경 10 cm 토화분에 심고 침선충 접종(3,000 P. projectus/100 ㎤ soil) 및 비접종으로 나누고 각 처리별 10반복으로 하여 온실에서 재배하고, 100일 후 식물의 생육, 초장, 무게, 엽수, 뿌리무게, soil plant analysis development, 선충 밀도를 조사하였다. P. projectus를 접종한 모든 작물은 무처리에 비하여 생육이 감소하였다. 지상부 무게를 기준으로 하여, 브로콜리와 갓이 56-66%로 가장 감수율이 컸고 치커리와 공심채의 수량 감수가 30-35%로 비교적 감수율이 적었다. 또한 선충의 증식률(Pf/Pi 비율)도 콜라비의 2.54에 비하여 엔다이브는 1.1, 치커리는 1.35, 공심채는 0.64로 비교적 낮게 나타났다. 따라서 이번 실험에 의하면, 상추 재배지의 윤작작물로는, 비록 충분하지는 않지만 효과적인 윤작작물을 찾기 전까지는, 다른 엽채류에 비하여 수량 감수가 비교적 적고, 선충의 증식률이 가장 낮은 공심채가 상추재배지의 윤작작물 대안일 것으로 판단된다.

• 한국유기농업학회지
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• 제23권4호
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• pp.897-909
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• 2015

우리나라 포도원에서 고품질 포도생산에 이용되고 있는 잡초관리 방법들이 병발생 및 수체생육과 과실품질에 미치는 영향을 구명하여 포도재배 농가에 실제적인 잡초관리 방법을 제공하고자 연구를 실시하였다. '캠벨얼리' 품종을 재배하는 비가림 포도원에서 잡초관리방법으로 포도가지 파쇄(C.B.), 흑색부직포(W.F.), 흑색차광망(S.N.), 흑색비닐(P.F.), 왕겨(R.H.), 기계제초 2회(M.W.2), 기계제초 3회(M.W.3)를 무처리와 비교하였다. 비가림 포도원의 피복처리구(C.B., W.F., S.N., P.F., R.H.)와 무피복처리구(M.W.2, M.W.3, U.T.)간 평균온도는 각각 $26.2^{\circ}C$와 $25.8^{\circ}C$로 비슷하였으나, 피복처리구의 지상부 습도는 피복처리구에서 7월에 90%로 유지되다가 7월 하순 이후 40% 이하로 급격히 낮아져 무피복처리구와 확연한 차이를 보였다. 토양수분은 무피복처리구에 비해 피복처리구에서 모두 높았으나 지온은 대체적으로 피복처리구가 낮았다. 피복처리별 갈색무늬병 발병은 흑색비닐피복에서 무처리 대비 7월에는 85%, 병발생이 높아지는 8월에는 69%의 감소효과를 보였고, 결과모지에서 병반 발생이 가장 적은 것으로 나타났다. 생육특성 중 절간장, 절간경은 무처리에 비해 흑색비닐 피복에서 생육이 좋았고 SPAD값은 흑색비닐 피복에서 가장 높았다. 과실품질 중 당도는 $14{\sim}15^{\circ}Brix$로 큰 차이는 없었으나 흑색비닐 피복에서 약간 높게 나타났다.