• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.49-49
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• 2020

Bacterial leaf blight (BLB), caused by X. oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice due to its high epidemic potential. Understanding BLB resistance at a genetic level is important to further improve the rice breeding that provides one of the best approaches to control BLB disease. In the present investigation, a total of 10,000 accessions of rice germplasm were tested to resistance degree of four Korean isolated races (K1, K2, K3 and K3a) of Xoo by bioassay and a diverse 268 accessions was selected to the genome-wide association study (GWAS) using high quality 34,724 SNPs to identify the associated with resistance loci. LOC_Os04g53160 of chromosome 4 was significantly associated with K1 race resistant. LOC_Os11g46230 and LOC_Os11g47150 of chromosome 11 were highly associated with K2 and K3 races as 23.7 and 27.4 of -log(P) value, but K3a resistant loci was weakly associated at LOC_Os03g55270 of chromosome 3. The results of the GWAS validate known gene of BLB resistant and identified novel loci of R genes that provide useful targets for further investigation to help the breeding system and identified gene and QTL provide valuable sources for further functional characterization.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.67.1-67
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• 2003

Phytophthora blight is a devastating disease of pepper and occurs almost anywhere peppers are grown. Phytophthora blight is caused by Phytophthora capsici and this pathogen can infect every part of the plant by moving inoculum in the soil, by infecting water on surface, by aerial dispersal to sporulating lesions. Management of Phytophthora blight currently relies on cultural practices, crop rotation, and use of selective fungicides. Since these treatments are a short-term management, a classical breeding for development of resistant pepper against the Phytophthora is an alternative. So far some of the resistant cultivars have been on the market, but those are limited regionally and commercially. Therefore, ultimately an elite line resistant against this disease should be developed, if possible, by biotechnology. We have set out a series of work recently in order to develop Phytophthora resistant pepper cultivar. For the first time, the cDNA microarray analysis was peformed using an EST chip that holds around 5000 pepper EST clones to identify genes responsive to Phytophthora infection. Total RNA samples were obtained from Capsicum annuum PI201234 after inoculating P. capsici to roots and soil and exposed to the chip. .Around 900 EST clones were up-regulated and down-regulated depending on the two RNA sample tissues, leaf and root. From those, we have found 55 transcription factors that may be involved in gene regulation of the disease defense mechanism. Further and in detail information will be provided in the poster.

• The Plant Pathology Journal
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• 제25권4호
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• pp.333-343
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• 2009

Here, we show that an endophytic bacterial strain, Enterobacter asburiae B1 exhibits the ability to elicit ISR in cucumber, tobacco and Arabidopsis thaliana. This indicates that strain B1 has a widespread ability to elicit ISR on various host plants. In this study, E. asburiae strain B1 did not show antifungal activity against tested major fungal pathogens, Colletotrichum orbiculare, Botrytis cinerea, Phytophthora capsici, Rhizoctonia solani, and Fusarium oxysporum. Moreover, the siderophore production by E. asburiae strain B1 was observed under in vitro condition. In greenhouse experiments, the root treatment of strain B1 significantly reduced disease severity of cucumber anthracnose caused by fungal pathogen C. orbiculare compared to nontreated control plants. By root treatment of strain B1 more than 50% disease control against anthracnose on cucumber was observed in all greenhouse experiments. Simultaneously, under the greenhouse condition, the soil drench of strain B1 and a chemical inducer benzothiadiazole (BTH) to tobacco plants induced GUS activity which is linked with activation of PR promoter gene. Furthermore, in Arabidopsis thaliana plants the soil drench of strain B1 induced the defense gene expression of PR1 and PDF1.2 related to salicylic acid and jasmonic acid/ethylene signaling pathways, respectively. In this study, for the main focus on root colonization by strain B1 associated with defense responses, bacterial cells of strain B1 was tagged with the gfp gene encoding the green fluorescent protein in order to determine the colonization pattern of strain B1 in cucumber. The gfp-tagged B1 cells were found on root surface and internal colonization in root, stem, and leaf. In addition to this, the scanning electron microscopy observation showed that E. asburiae strain B1 was able to colonized cucumber root surface.

• 한국환경복원기술학회지
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• 제16권1호
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• pp.147-157
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• 2013

Rice is a main crop and rice field is the most important farmland in Korea. This study was conducted to propose the methodology assessing impact and vulnerability on rice production by climate change at the regional and national level in Korea. We evaluated a vulnerability of rice paddy according to the outbreak of a main disease and pest of a rice plant. As results, Jeju-do, Gyeongsangnam-do, and Jeollanam-do were more vulnerable area than others. In contrast, the southern central region including Gyeonggi-do was less vulnerable than others. The vulnerable index was significantly higher in 2050s (0.5589) than in present (0.3500). This result showed that the vulnerable to the disease and pest enlarge in the future. The adaptive capacity highly contributed to the vulnerability assessment index. The daily maximum temperature of June and the daily average temperature from May to August also contributed the climate exposure index. The area of occurring sheath blight, rice leaf blast and striped rice borer was related to the system sensitivity index. The ability of water supply (readjustment area of arable land per paddy field area) and rice production technique (rice yield per hectare) were the highly contributed variables to the adaption capacity index.

• 식물병연구
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• 제17권1호
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• pp.95-98
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• 2011

국내 당근 유기재배를 위한 저항성 품종 선발을 목적으로 한 실험에서는 당근 유전자원 32품종을 이용하여 병저항성(흰가루병, 검은무늬병, 검은잎마름병) 검정, 내충성 및 추대 정도를 조사하였다. 흰가루병 스크리닝 결과 'PI 223360'이 저항성이었으며, 'Oxheart Carrot Heirloom'를 포함한 10개의 품종이 중도저항성이었고 'Long Impeator #58'을 포함한 22품종이 감수성인 것으로 나타났다. 당근 검은무늬병과 검은잎마름병의 스크리닝 결과 모든 품종이 저항성을 나타내진 않았지만, 몇몇 품종이 중도저항성을 가진 것으로 확인되었다. 내충성을 조사한 결과 'Oxheart Carrot Heirloom'를 포함한 13품종이 내충성인 것으로 조사되었으며, 'Nantes Coreless Carrot'을 포함한 11개의 품종들이 중간정도를 나타냈으며 'SA 102'와 'Scarlet Keeper Carrot Rare'은 감수성인 것으로 조사되었다. 추대조사 결과에서는 'Hongsim Ouchon Carrot'을 포함한 6개의 품종이 이른 추대를 보였으며, 'Japanese Imperial Long Carrot'를 포함한 4개 품종이 중간 추대를 나머지는 만추대성인 것을 확인하였다. 이상의 결과를 근거로 'Oxheart Carrot Heirloom'이 조사한 32개 당근 유전자원 중 유기재배를 위한 품종으로 선발되었다.

• The Plant Pathology Journal
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• 제36권6호
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• pp.579-590
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• 2020

Botrytis cinerea, which causes gray mold disease in more than 200 plant species, is an economically important pathogen that is mainly controlled by synthetic fungicides. Synergistic fungicide mixtures can help reduce fungicide residues in the environment and mitigate the development of fungicide-resistant strains. In this study, we screened microbial culture extracts on Botrytis cinerea to identify an antifungal synergist for tebuconazole. Among the 4,006 microbial extracts screened in this study, the culture extract from Schizophyllum commune displayed the most enhanced activity with a sub-lethal dosage of tebuconazole, and the active ingredient was identified as schizostatin. In combination with 5 ㎍/ml tebuconazole, schizostatin (1 ㎍/ml) showed disease control efficacy against gray mold on tomato leaf similar to that achieved with 20 ㎍/ml tebuconazole treatment alone. Interestingly, schizostatin showed demethylation inhibitor (DMI)-specific synergistic interactions in the crossed-paper strip assay using commercial fungicides. In a checkerboard assay with schizostatin and DMIs, the fractional inhibitory concentration values were 0.0938-0.375. To assess the molecular mechanisms underlying this synergism, the transcription levels of the ergosterol biosynthetic genes were observed in response to DMIs, schizostatin, and their mixtures. Treatment with DMIs increased the erg11 (the target gene of DMI fungicides) expression level 15.4-56.6-fold. However, treatment with a mixture of schizostatin and DMIs evidently reverted erg11 transcription levels to the pre-DMI treatment levels. These results show the potential of schizostatin as a natural antifungal synergist that can reduce the dose of DMIs applied in the field without compromising the disease control efficacy of the fungicides.

• 식물병연구
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• 제25권3호
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• pp.108-113
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• 2019

북한의 작물 생산성은 남한에 비하여 월등히 낮다. 이러한 이유 중 하나는 취약한 병 관리에 있다. 북한은 농경지의 약 30%가 논으로 이루어져 있다. 벼 도열병과 벼 흰잎마름병은 북한 벼 재배 시 각각 가장 중요한 곰팡이 병 및 세균 병이다. 본 연구에서는 벼 도열병균과 벼 흰잎마름병균에 대한 7개 북한 벼 품종의 병 저항성 반응을 시험하였다. 남한에서 분리한 18개 벼 도열병균에 대한 7개 벼 품종의 반응은 다소 다르게 나타났다. 7개 벼 품종 중 길주1호는 KI 혹은 KJ 레이스에 관계없이 남한에서 분리한 벼 도열병균 18개 균주 모두에 매우 저항성을 보였다. 평도5호는 남한에서 분리한 벼 도열병균 15개 균주에 대하여 감수성 반응을 보였다. 반면, 벼 흰잎마름병균에 대한 북한 벼 품종의 병 저항성 반응은 벼 도열병균에 대한 반응과 차이를 보였다. 길주1호는 K1 레이스인 KXO42와 K2 레이스인 KXO90에 대하여 높은 감수성을 보였고, 평도5호는 K1 레이스인 KXO85와 K3 레이스인 KXO19에 완전한 저항성을 보였다. 평양21호는 K1 레이스 모두에 완전한 저항성을 보였고, 원산69호는 KXO85를 제외한 모든 벼 흰잎마름병균에 감수성을 보였다. 이 연구는 향후 남북 농업 협력을 통하여 북한 벼 품종을 남한에 도입 시 두 병원균에 대한 북한 벼 품종의 저항성 반응 검정 및 벼 품종 육성에 중요한 기본 자료가 될 것이다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.73.2-73
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• 2003

Typical whiches broom symptoms caused by phytoplasma were observed in Ash (Fraxinus rhynchophylla Hence) in Korea. The symptoms were showing abnormally small leaves, short internodes, and proliferation of shoots. Fluorescence and electron microscopy of leaf midribs revealed phytoplasma positive DAPI fluorescence and numerous phytoplasma bodies localized in the phloem sieve tubes. Phytoplasma DNA of 1.8 Kb was detected consistently from all symptomatic samples by the amplification of phytoplasma DNA with the phytoplasma specific primer pair Pl/P7. But no phytoplasma DNA was detected in healthy ash seedlings. Based on sequence analyses of an amplified region, this phytoplasma is closely related to Eqilodium phyllody, Mulberry dwarf, and Aster yellows phytoplasmas with the homology of 99.95 ％, 99.79 ％ and 99.78 ％, respectively, This phylogenetic analyses indicate that ash witches broom phytoplasma but is evidently distinct from the ash yellows group 16SrⅦ and should be classified into the Aster yellows group 16SrⅥ.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.262-266
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• 2018

Phytochemicals have been considered as alternatives for synthetic fungicides because of their biodegradability and low toxicity. In this study, we found that the methanolic extract of Corydalis ternata suppressed the development of plant diseases caused by Puccinia triticina and Colletotrichum coccodes. As the antifungal substance, three isoquinoline alkaloids (dehydrocorydaline, stylopine, and corydaline) were isolated from C. ternata. These active compounds also exhibited in vivo antifungal activity against P. triticina and C. coccodes. Taken together, our results suggest that C. ternata and its active compounds can be used to control plant diseases.

• The Plant Pathology Journal
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• 제34권3호
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• pp.157-162
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• 2018

The objective of this work was to accomplish the isolation, molecular identification and characterizing the physiology of the causal agent of the algal spot in mango trees. For this purpose, the pathogen growth was assessed in different culture media, with subsequent observation and measurements of the filamentous cells. The molecular identification was made using mycelium obtained from leaf lesions and pure algae colonies grown in culture medium. Descriptions based on DNA sequencing indicated that the algae is Cephaleuros virescens. The algae must be isolated primarily in liquid medium for further pricking into agar medium. The highest mycelial growth average in Petri dishes occurred when the algae were grown in Trebouxia and BBM. Trebouxia enabled larger cells in the filamentous cells when compared to other culture media.