• The Plant Pathology Journal
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• 제19권3호
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• pp.133-137
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• 2003

Seedborne fungus Bipolaris spicifera, which has not been previously reported in Korea, was detected from import-ed grass seeds in the country. The most frequently detected fungi from the seeds were Fusarium species, Ulocladium atrum, B. spicifera, Alternaria, and Cuvularia lunata among 17 different seed samples of the family Gramineae. Detection frequencies of B. spicifera were 11,8,5% in Bermuda grass, tall fescue, and mixed lawn grass imported from USA, respectively, and 9％ in mixed lawn grass imported from Italy. This suggests that important seedborne pathogen could be spread between countries through seed sources. The pathogen was seed-transmitted causing damping-off of Bermuda grass seedlings and showed strong pathogenicity to vice, corn, Bermuda grass, sorghum, and tall fescue. However, it did not infect wheat and blue grass.

• 한국작물학회지
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• 제29권3호
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• pp.280-284
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• 1984

콩모자이크 바이러스(SMV)에 의한 갈반립의 형성율과 SMV의 종자전염율을 조사하기 위하여 대두품종 Clark, Woodworth, 북해1호를 재료로 SMV 이병정도와 갈반립율 결협절위 및 갈반립형성등의 관계를 조사하고 그 갈반립을 통한 SMV의 종자전염율을 면역이중확산법과 유묘감염률로 조사하였다. 1. 갈반립의 형성율은 식물체의 이병정도와 정비례적인 상관(r=0.796)을 보였다. 2. 이병식물체의 갈반립형성은 결협절립 및 협중종실위치와 유의상관이 없었으며 (r=0.34), 동일절위 및 협내에서도 갈반립과 비갈반립이 함께 형성되었다. 3. 면역이중확산법으로 조사한 SMV의 종자전염율은 4.2 -33.3％로 비교적 낮았으며 품종에 따라 현저한 차이가 있었다. 4. 유묘에 나타난 SMV 증상으로 조사한 종자전염율은 면역이중확산법으로 검정한 종자감염율보다 약관 높게 나타났으며 이는 항혈청의 역가 또는 Virus의 체내증식과 관계가 있는 것으로 보였다. 5. 이병직물의 갈반립은 SMV 종자전염율과 일치하지는 않으나 SMV의 포장이병율 추정에 유용한 지표가 될 수 있으며 파종시 갈반립의 제거는 SMV 전염원의 감소효과를 가져올 수 있을 것으로 보였다.

• 한국식물병리학회지
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• 제11권3호
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• pp.217-223
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• 1995

Nature of graft transmissibility of pear abnormal leaf spot disease was examined by various grafting methods in the greenhouse and field. When the diseased and symptomless twigs were collected in winter and grafted in the next spring to the seed-originated healthy root stock, the abnormal leaf spot was developed only in the case of the diseased twigs. Double grafting on a seed-originated healthy root stock, where the diseased and the symptomless twigs were used as 1st and 2nd scions, respectively, developed abnormal leaf spot lesions without exception on the 2nd scions. Tongue-graft with the diseased and the symptomless trees also incited abnormal leaf spots on the both trees. Abnormal leaf spots of were also developed on HN-39, an indicator pear tree, used as a 2nd scion in a double graft test, where the diseased twig and a seed-originated healthy tree were used as the 1st scion and the root stock, respectively. When the diseased twig was top-grafted to the healthy root stock, lesion development of abnormal spot was limited to the grafted twig itself in the 1st year, but expanded to the main branches in the 2nd year, and spread over the whole tree in the 3rd year. This result indicates that the causal agent of abnormal leaf spot disease is transmitted by graft.

• The Plant Pathology Journal
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• 제33권4호
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• pp.424-428
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• 2017

Tomato yellow leaf curl virus (TYLCV) infection of the common bean (Phaseolus vulgaris) has been reported, but soybean (Glycine max) has not previously been identified as a TYLCV host. Five cultivars of white soybean were agro-inoculated using an infectious TYLCV clone. At 30 days post-inoculation, they showed infection rates of 25% to 100%. Typical TYLCV symptoms were not observed in any inoculated plants. To examine whether TYLCV was transmitted in soybean seeds, DNA was isolated from bundles of five randomly selected seeds from TYLCV-inoculated soybean plants and amplified with a TYLCV-specific primer set. With the exception of one bundle, all bundles of seeds were verified to be TYLCV-infected. Virus dissemination was also confirmed in three of the 14 bunches. Viral replication was also identified in seeds and seedlings. This is the first report demonstrating that soybean is a TYLCV host, and that TYLCV is a seed-transmissible virus in white soybean.

• The Plant Pathology Journal
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• 제38권4호
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• pp.334-344
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• 2022

Bacterial wilt is a re-emerging disease on dry bean and can affect many other crop species within the Fabaceae. The causal agent, Curtobacterium flaccumfaciens pv. flaccumfaciens (CFF), is a small, Gram-positive, rod-shaped bacterium that is seed-transmitted. Infections in the host become systemic, leading to wilting and economic loss. Clean seed programs and bactericidal seed treatments are two critical management tools. This study characterizes the efficacies of five bactericidal chemicals against CFF. It was hypothesized that this bacterium was capable of forming biofilms, and that the cells within biofilms would be more tolerant to bactericidal treatments. The minimum biocide eradication concentration assay protocol was used to grow CFF biofilms, expose the biofilms to bactericides, and enumerate survivors compared to a non-treated control (water). Streptomycin and oxysilver bisulfate had EC95 values at the lowest concentrations and are likely the best candidates for seed treatment products for controlling seed-borne bacterial wilt of bean. The results showed that CFF formed biofilms during at least two phases of the bacterial wilt disease cycle, and the biofilms were much more difficult to eradicate than their planktonic counterparts. Overall, biofilm formation by CFF is an important part of the bacterial wilt disease cycle in dry edible bean and antibiofilm bactericides such as streptomycin and oxysilver bisulfate may be best suited for use in disease management.

• 식물병연구
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• 제9권1호
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• pp.1-9
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• 2003

The occurrence of potato(Sotanum tuberosum) viral diseases caused by Potato virus X(PVX), Potato virus Y (PVY), Potato leafroll virus(PLRV), Potato vims S(PVS), Potato virus M(PVM), Potato virus A(PVA), Potato virus T(PVT), Alfalfa mosic virus(AIMV), Tobacco mosic virus(TMV), Potato mop top virus(PMTV) Tobacco rattle virus(TRV) and Potato spindle tuber viroid(PSTVd), potato witches' broom phytoplasma, have been identified so far in Korea. Major viral diseases such as PVX, PVY and PLRV had been studied more deeply, however, the others are just identified and only partially characterized since the first study on the relation between PVX nucleic acid and virus protein by Kim in 1961. The most studies on potato viral diseases are mainly focused on the problems of seed potato production. The National Alpine Agricultural Experiment Station(NAAES), since it began its activities in 1961, has given special attention to this problem by doing studies to identify, characterize and control potato virus diseases. This effort resulted in the development of new potato virus detection methods as a basis for elaborating new method of control, such as the production of seed potato free of virus and the selection of new virus-resistant transgenic potatoes. The further studies of potato viral diseases required would be fallowings: the continuous monitoring for the occurrence of identified or not identified potato viruses in Korea, the isolation of resistant viral genes, the development of control method for the non-persistently transmitted viruses like PVY, special vectors such as nematode and fungus transmitted viruses, TRV and PMTV and the development of control methods against potato viral diseases by viral cross protection, therapy, transgenic plant, and the use of the agents or molecules, such as virus inhibitors and antiviral proteins, etc., blocking viral replication.

• 한국응용곤충학회지
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• 제18권3호
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• pp.119-126
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• 1979

깨씨무늬병에 심하게 이병된 병팔굉 공시종자는 배양 $5\~7$일에 호영, 내외영 및 주병의 $86\~92\%$ 그리고 과피의 $74\~83\%$가 Helminthosporium oryzae에 감염 되어 있음을 보였다. 동균은 종립전면에 분생포자를 형성하였으며 배유의 약10여세포층까지 감염되어 있었으나 배조직에서는 검출되지 않았다. Fusarium moniliforme는 과피, 경유 및 배조직에서 검출되었으며 F. roseum, Trichoconis padwicku, Curvularia spp., Alternaria tenuis, Cladosporium cladosporoides 및 Phoma sp.는$ 3\%$ 이하의 영 및 과피에서 검출되었다. 배양일주일에 $60\~87\%$가 깨씨무늬 병징을 나타냈으며 $13\~40\%$는 외관상 건전하였다. 깨씨무늬병균은 감염된 종자의 제점으로부터 과피를 거쳐 시아및 유근에 전염 발병케 하였다.

• 한국산학기술학회논문지
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• 제11권10호
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• pp.3942-3949
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• 2010

기존 네이트온은 사용자의 개인 정보를 서버의 데이터베이스에 저장을 하기 때문에 내부자 공격에 취약하고, 사용자간의 통신 내용도 그대로 송.수신되었다. 이러한 정보노출 문제점을 해결하기 위한 안전한 메신저를 구현하였다. 본 논문에서 제안한 메신저에서는 서버에게 사용자의 최소한의 개인정보만을 공개하고 중요한 개인정보는 사용자만 알고 있는 패스워드로 암호화하여 서버의 DB에 저장한다. 서버 관리자 또는 제 3자는 악의적인 의도로 사용자의 중요한 정보를 알 수 없다. 또한 네트워크상에 노출되었던 통신 내용도 송.수신 시 암 복호화 되어 때문에 안전하게 통신을 할 수 있다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.161-161
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• 2017

Seed endophytes are very remarkable groups of bacteria for their unique abilities of being vertically transmitted and conserved. As plants attain hybrid vigor and heterosis in the process of crossbreeding, this might also lead to the changes in the community structure and diversity of plant endophytes in the hybrid plants ultimately affecting the endophytes of the seeds. It would be interesting to characterize how seed endophyte composition change over time. The objective of this study is to gain insights into the influence of natural crossbreeding and parental lineage in the seed bacterial endophytic communities of two pure inbred lines exploring contributions of the two most important sources of plant endophytes - colonization from external sources and vertical transmission via seeds. Total genomic DNA was isolated from rice seeds and bacterial DNA was selectively amplified by PCR. The diversity of endophytic bacteria was studied through Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis. Diversity between the original parents and the pure inbred line may show significant differences in terms of richness, evenness and diversity indices. Heat maps reveal astonishing contributions of both or either parents (IR29 ${\times}$ Pokkali and AT401 ${\times}$ IR31868) in the shaping of the bacterial seed endophytes of the hybrid, FL478 and IC32, respectively. Most of the T-RFs of the subsequent pure inbred line could be traced to any or both of the parents. Comparison of common and genotype-specific T-RFs of parents and their offspring reveals that majority of the T-RFs are shared suggesting higher transmission of bacterial communities common to both parents. The parents influence the bacterial community of their offspring. Unique T-RFs of the offspring also suggest external sources of colonization particularly as the seeds are cultivated in different ecogeographical locations. This study showed that host parental lines contributed greatly in the shaping of bacterial seed endophytes of their offspring. It also revealed transmission and potential conservation of core seed bacterial endophytes that generally become the dominant microbiota in the succeeding generations of plant hosts.

• Mycobiology
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• 제50권5호
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• pp.382-388
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• 2022

White mold (or Sclerotinia stem rot), caused by Sclerotinia species, is a major air, soil, or seed-transmitted disease affecting numerous crops and wild plants. Microscopic or culture-based methods currently available for their detection and identification are time-consuming, laborious, and often erroneous. Therefore, we developed a multiplex quantitative PCR (qPCR) assay for the discrimination, detection, and quantification of DNA collected from each of the three economically relevant Sclerotinia species, namely, S. sclerotiorum, S. minor, and S. nivalis. TaqMan primer/probe combinations specific for each Sclerotinia species were designed based on the gene sequences encoding aspartyl protease. High specificity and sensitivity of each probe were confirmed for sclerotium and soil samples, as well as pure cultures, using simplex and multiplex qPCRs. This multiplex assay could be helpful in detecting and quantifying specific species of Sclerotinia, and therefore, may be valuable for disease diagnosis, forecasting, and management.