• 한국응용곤충학회지
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• 제20권3호
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• pp.131-134
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• 1981

대두 자주빛무늬병에 대한 저항성인자원 선발을 위하여 한국에너지연구소, 방사선농학연색실이서 보존하고 있는 수집재내종을 자연감염율과 인공접종법에 의한 저항성검정을 실시하였다. 공시한 수집재래종 467 계통중 $28.9\%$는 $0.1\%$이하의 감염율을, 약 $13.4\% $는 $2\%$ 이상의 감염율을 보였으며 이 자연감염율은 결협초기의 기상조건과 밀접한 상관을 보였다. 종자접종에 의한 자반의 형성은 자연감염율과 정의 상관을 보여 일차적인 저항성 검정방법으로서 효과적이었으며 만숙대두계통은 병해도피에 의한 저항성을 보였다. 그리고 갈색무늬병균의 병원성과 관계되는 종자의 자반정도는 배양기의 착색정도와 높은 상관을 보였다.

• 한국작물학회지
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• 제27권2호
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• pp.137-140
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• 1982

두과목초의 근류균 접종방법 개선책의 일환으로써 3수준의 근류균농도, 즉 10, 20, 30%; 3종류의 접착제 즉 gum arabic, methyl cellulose 및 carboxy methyl cellulose; 그리고 4종류의 석회와 calcium carbonate를 포함한 5종류의 피복재료를 사용하여 근류균을 접종한 후에 plate count법으로 생존하고 있던 근류세포수를 측정하여 그 효과를 평가하였던 바 다음과 같은 결론을 얻었다. 1. New Zealand산 peat slurry의 근류균을 사용할 경우 근류균을 10%에서 3.5$\times$$10^9$ 개로써 표준에 가까운 근류균수를 확보할 수 있었다. 2. 접착제로서 gum arabic은 40% 용액에서 methyl cellulose는 5% 용액 그리고 carboxy methyl cellulose는 4% 용액으로 사용하였을 때 최대착생수를 나타내었으나 그 중에서 methyl cellulose 5% 용액이 적합한 것으로 보였다. 3. 피복재료로서 치과용석회(Lime A)는 타재료에 비하여 양호한 결과를 얻을 수 있었다.

• The Plant Pathology Journal
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• 제28권1호
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• pp.55-59
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• 2012

Northern stem canker caused by $Diaporthe$ $phaseolorum$ var. $caulivora$ ($Dpc$) has become a serious disease in soybean. The objectives of this study were to survey the existence of $Dpc$ on soybean in Korea, and to examine the potential pathogenicity of $Dpc$ in seed decay. One such isolate, SSLP-4, isolated from a field-grown plant of the Korean soybean cultivar Danbaekkong, was identified as $Dpc$, based on its morphological and molecular characteristics by sequences of internal transcribed spacer (ITS), translation elongation factor (TEF) 1-${\alpha}$ and ${\beta}$-tubulin regions, as well as pathogenic analyses. Moreover, morphological and molecular analyses revealed that isolate SSLP-4 was nearly identical to $Dpc$ strains from the United States. Pathogenicity tests on hypocotyls of soybean seedlings and detached leaves resulted in typical symptoms of soybean northern stem canker and inoculation on plants at R5-R7 stage caused seed decay. All results suggest that the $Dpc$ strain SSLP-4 can cause both stem canker and seed decay on soybean. Thus, the SSLP-4 isolate has the potential to contribute greatly to understanding of host plant resistance mechanisms, both at vegetative and reproductive growth stages in soybean.

• 한국토양비료학회지
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• 제37권1호
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• pp.41-45
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• 2004

충북지역의 근권 토양으로부터 선발한 인산가용화 균인 Pantoea agglomeraans와 인광석을 복합처리하여 벼(Oryza sativa L.)의 생육 및 인산 흡수량에 미치는 영향을 온실내에서 실험하였다. 본 실험은, 종자에 박테리아를 적용시킨 것(bactenzation), 독립 세포 및 고정화된 세포(immobilized cell)를 접종시킨 후, 인광석 1 g과 2.5 g을 각각 시비한 6처리구와 무처리구로 나누어 비교 실험하였다. 인산가용화균을 접종한 처리구가 무처리구에 비하여 벼의 생육 및 인산 흡수량을 증대하는 경향을 나타냈으며, 특히 1 g의 인광석과 고정화된 Pantoea agglomerans를 접종한 처리구에서 다른 처리구들에 비해 가장 우수한 결과를 나타내었다. Pot 충진물내의 유효인산 농도 또한 미생물 접종 처리구에서 증가하였으며, 벼에 흡수된 전인산량과 정의 상관관계가 성립함을 알 수 있었다.

• 한국작물학회지
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• 제63권1호
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• pp.57-63
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• 2018

The effects of endophytic microbial inoculation and temperature on the phenolic content of tartary buckwheat (TP) sprouts were investigated. TP seeds were inoculated with Herbaspirillum spp. at concentrations (%v/v) of 0 (control), 10, 20, and 40% at 20, 25, and $30^{\circ}C$ in a growth chamber for seven days. It was observed that the phenolic content (PC) including flavonoid, rutin, and tanin increased with an increase in inoculant rate at $20^{\circ}C$, whereas the PC content increased with an increase in temperature regardless of the inoculant rate. Therefore, it is suggested that increasing the inoculant rate is effective at achieving higher phenolic contents when plants are grown at lower temperatures.

• The Plant Pathology Journal
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• 제36권1호
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• pp.29-42
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• 2020

Acidovorax citrulli causes bacterial fruit blotch in Cucurbitaceae, including watermelon. Although A. citrulli is a seed-borne pathogen, it can cause diverse symptoms in other plant organs like leaves, stems and fruits. To determine the infection routes of A. citrulli, we examined the virulence of six isolates (Ac0, Ac1, Ac2, Ac4, Ac8, and Ac11) on watermelon using several inoculation methods. Among six isolates, DNA polymorphism reveals that three isolates Ac0, Ac1, and Ac4 belong to Clonal Complex (CC) group II and the others do CC group I. Ac0, Ac4, and Ac8 isolates efficiently infected seeds during germination in soil, and Ac0 and Ac4 also infected the roots of watermelon seedlings wounded prior to inoculation. Infection through leaves was successful only by three isolates belonging to CC group II, and two of these also infected the mature watermelon fruits. Ac2 did not cause the disease in all assays. Interestingly, three putative type III effectors (Aave_2166, Aave_2708, and Aave_3062) with intact forms were only found in CC group II. Overall, our results indicate that A. citrulli can infect watermelons through diverse routes, and the CC grouping of A. citrulli was only correlated with virulence in leaf infection assays.

• The Plant Pathology Journal
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• 제34권2호
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• pp.126-138
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• 2018

Rice blast caused by Magnaporthe oryzae is a major disease. In the present study, we aimed to identify and evaluate the novel bacterial isolates from rice rhizosphere for biocontrol of M. oryzae pathogen. Sixty bacterial strains from the rice plant's rhizosphere were tested for their biocontrol activity against M. oryzae under in vitro and in vivo. Among them, B. amyloliquefaciens had significant high activity against the pathogen. The least disease severity and highest germination were recorded in seeds treated with B. amyloliquefaciens UASBR9 (0.96 and 98.00%) compared to untreated control (3.43 and 95.00%, respectively) under in vivo condition. These isolates had high activity of enzymes in relation to growth promoting activity upon challenge inoculation of the pathogen. The potential strains were identified based on 16S rRNA gene sequencing and dominance of these particular genes were associated in Bacillus strains. These strains were also confirmed for the presence of antimicrobial peptide biosynthetic genes viz., srfAA (surfactin), fenD (fengycin), spaS (subtilin), and ituC (iturin) related to secondary metabolite production (e.g., AMPs). Overall, the results suggested that application of potential bacterial strains like B. amyloliquefaciens UASBR9 not only helps in control of the biological suppression of one of the most devastating rice pathogens, M. grisea but also increases plant growth along with a reduction in application of toxic chemical pesticides.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1994년도 Proceedings of International Symposium on BIOLOGICAL CONTROL OF PLANT DISEASES Korean Society of Plant Pathology
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• pp.27-49
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• 1994

Root colonization of biocontrol agents via seed treatment was investigated and a compatible combination, Gliocladium virens G872B and Pseudomonas putida Pf3, in colonizing cucumber rhizosphere was confirmed through the study. Much higher number of fungal and bacterial propagules were detected when two isolates were inoculated together. The presence of Pf3 in root system was greatly helpful to G872B to colonize at root tip. The mechanism of this phenomenon is partially elucidated through the results of in vitro experiments and the observations of scanning electron and fluorescence microscope. Addition of Pf3 cells resulted earlier germination of G872B conidia and increased mycelial growth. And the more number of germinated conidia on seed coat, the more vigorous hypal streching and sporulation on the root surface were observed in coinoculated treatment. The propagules of G872B on the cucumber root when they were challenged against the pathogenic Fusarium oxysporum, were even higher than that of G872B treated alone, and the magnitude of such a difference was getting grater toward the root ip and the population of F. oxysporum on the root was reduced by seed inoculation of G872B. The rhizosphere competence was obviously reflected to disease suppression and plant growth promotion that induced by the given isolate. Green house experiments revealed that the combined treatment provided long-term disease suppression with greater rate and the larger amount of fruit yield than single treatments. Through this study the low temperature growing Pseudomonas fluorescens M45 and MC07 were evaluated to apply them to the winter crops in field or plastic film house. In vitro tests reveal that M45 and MC07 inhibited the mycelial growth of Pythium ultimum, Rhizoctona solani and Phytophthora capsici and enhanced growth of cucumber cotyledon in MS agar. This effect was more pronounced when the bacteria were incubated at 14$^{\circ}C$ than at 27$^{\circ}C$. And disease suppression and plant growth promotion in green house were also superior at low temperature condition. Seed treatment of M45 or soil treatment of MC07 brought successful control of damping-off and enhanced seedling growth of cucumber. The combined treatment of two isolates was more effective than any single treatment.

• The Plant Pathology Journal
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• 제35권3호
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• pp.219-233
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• 2019

Soybean cultivars susceptible to Phytophthora root and stem rot are vulnerable to seed rot and damping-off of seedlings and young plants following an infection by Phytophthora sojae. In this study, the disease responses of Japanese soybean cultivars including currently grown main cultivars during the early growth stages were investigated following infections by multiple P. sojae isolates from Japanese fields. The extent of the resistance to 17 P. sojae isolates after inoculations at 14, 21, and 28 days after seeding varied significantly among 18 Japanese and two US soybean cultivars. Moreover, the disease responses of each cultivar differed significantly depending on the P. sojae isolate and the plant age at inoculation. Additionally, the treatment of 'Nattosyo-ryu' seeds with three fungicidal agrochemicals provided significant protection from P. sojae when plants were inoculated at 14-28 days after seeding. These results indicate that none of the Japanese soybean cultivars are completely resistant to all tested P. sojae isolates during the first month after sowing. However, the severity of the disease was limited when plants were inoculated during the later growth stages. Furthermore, the protective effects of the tested agrochemicals were maintained for at least 28 days after the seed treatment. Japanese soybean cultivars susceptible to Phytophthora root and stem rot that are grown under environmental conditions favorable for P. sojae infections require the implementation of certain practices, such as seed treatments with appropriate agrochemicals, to ensure they are protected from P. sojae during the early part of the soybean growing season.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권5호
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• pp.9-17
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• 2011

Positive effect of multiple-PGPR (Plan Growth Promoting Rhizobacteria), isolated from heavy metal contaminated soil, on the germination of Barnyard grass (Echinochloa crus-galli var. frumentacea) was quantitatively estimated in 5 heavy metal (Cd, As, Ni, Cu, and Pb) contaminated liquid medium. The $EC_{50}$ value for respective heavy metal was estimated by TSK (Trimmed Speraman-Karber) model based on germination rate. The results showed overall increase in $EC_{50}$ with PGPR inoculation. The $EC_{50}$ value increased 1.4% from 96.0 mg/L (control) to 97.4 mg/L (PGPR-treated) in As contaminated medium. In Ni contaminated medium, the $EC_{50}$ value increased 31.9% from 148.0 mg/L (control) to 195.2 mg/L (PGPR-treated), while the $EC_{50}$ showed 4.8% increase from 63.4 mg/L (control) to 66.5 mg/L (PGPR-treated) in Cu medium. Overall seedling growth was stronger in the PGPR treated seeds than that in the control, but positive effect on seedling growth was not conspicuous. At effective concentration of 100 mg/L, the average seedling length of the PGPR treatment in As, Cd, Cu, and Ni medium, respectively, was 1.13, 0.14, 0.40, and 0.06 cm longer than that in the control. However, the increase of seedling growth was statistically insignificant (p < 0.05). These results suggest that inoculation of the isolated-PGPR exerts positive effects on seed germination by reducing heavy metal toxicity and can be an effective tool for application of phytoremediation on heavy metal contaminated soils.