• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5716-5720
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• 2015

This study has analyzed the backwater effect by the bridge pier on the basis of the result on hydraulic characteristics with pier shapes in study(I), using a two-dimensional model(RMA-2) and an one-dimensional model(HEC-RAS). The pier shapes are classified into total six types such as square, rhombus, octagon, oval, round, and no-piers. The result of the backwater effect analysis showed that the backwater length is about 150 and 50m from HEC-RAS and RMA-2, respectively for all pier types. Although it is difficult to directly compare between results from the two models, the oval shape pier has shown similar results to the no-pier situation before the bridge construction in hydraulic characteristics. This analysis can help to select pier types in the new bridge construction for the future.

• The Korean Journal of Mycology
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• v.49 no.4
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• pp.539-545
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• 2021

A cercosporoid fungus associated with angular leaf spots on the leaves of common fig (Ficus carica) in Korea is known to be morphologically similar to Passalora, but phylogenetically similar to Pseudocercospora. To clarify the ambiguity, six fig samples with angular leaf spots were collected and examined using a microscope, and two representative isolates were sequenced for multiple genes. The morphological characteristics were consistent with previous descriptions of Passalora bolleana. Molecular phylogenetic analysis based on the internal transcribed spacer and large subunit ribosomal DNA (rDNA) regions showed that the Korean isolates, as well as previously published Korean and Romanian isolates, formed a well-supported group in the clade of Pseudocercospora species. Consequently, the current Korean isolates should be correctly described as Pseudocercospora bolleana. Additionally, Pseudocercospora fici-caricae, a cercosporoid fungus previously described as a leaf pathogen on common fig in Taiwan and Korea, was also compared and discussed.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.160-164
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• 2011

경기도 안산시 시화습지내에 위치한 하안 유도 시험장에 직선수로와 곡선수로를 시공하였다. 각각의 수로에 유도틀을 설치한 후 수리학적 특성을 분석하기 위해서 2차원 모형인 SMS를 이용하여 유량조건에 따른 유속 및 침식, 퇴적에 미치는 영향을 분석하고 예측하였다. SMS 모형 중 2차원 수리분석을 위한 RMA2 모형과 유사이송현황을 모의할 수 있는 SED2D 모형을 이용하여 하안유도 시험장에 적용하였으며 하안 유도 시험장은 크게 직선수로와 곡선수로로 구분하였다. 각각의 수로에 설치되는 유도틀은 ㄷ자형, ㄷㅂ자형, 직사각형, 마름모형이 있고, 총 10가지 경우로 하여 시험장 유도틀 형태별 2차원 수치모의를 분석하였다. 유속을 모의하기 위해 RMA2모형을 사용하였으며, 침식 및 퇴적을 모의하기 위해 SED2D모형을 사용하였다. 이러한 모의결과를 통해 실제 하천에서 유도틀 시공시 유량에 대한 하류 구간 대책을 수립하는 기초자료 활용하고자 한다.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.323-328
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• 2015

Control efficacy was investigated with fungicides as 3 copper compound, 3 antibiotic fungicides and one fungicide containing to quinolone against the growth of Ralstonia solanacearum on NA medium and the disease occurrence on pepper seedlings. Among 7 fungicides, oxytetracycline was shown the highest activity against a growth of the pathogen in the agar diffusion method, but validamycin showed no activity against the pathogen. With $1000{\mu}g\;mL^{-1}$ of each copper fungicide as copper hydroxide, copper oxychloride+ dithianone and copper sulfate, 2.2, 1.3 and 1.5 mm in size of clear zone only could be found, respectively. In pepper seedling test, oxytetracycline showed a perfect activity in all treatments 7 days after inoculation. However, its activity was decreased from $500{\mu}g\;mL^{-1}$ of treatment over the time. Copper fungicides showed the control efficacy lower than antibiotic fungicides except for validamycin. Based on the results, it was suggested that it would be better to use antibiotic fungicides than copper fungicides to control pepper bacterial wilt in the fields.

• Research in Plant Disease
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• v.11 no.2
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• pp.193-197
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• 2005

The effect of pH on the survival of R. solanacearum and its transmission via roots of tomato in hydroponic culture were studied in laboratory and greenhouse. In laboratory experiment, R. solanacearum could not survive for 24h in nutrient solution with pH of $4{\cdot}0;or\;4{\cdot}5$, while 1, 14, 51 and $62\%$ of inoculum survived at pH $5{\cdot}0,\;5{\cdot}6\;and\;6{\cdot}5$, respectively. When tomato plants were inoculated with R. solanacearum through wounds on the stems, the bacteria moved downward from the inoculation site to the roots and infectious bacteria were released from the roots into the nutrient solution. Of two pH regimes tested in greenhouse nutrient-film technique(NFT) culture, the R. solanacearum population was significantly lower in pH 5.0 than in pH 6.5 in most sampling data. In treatments in which R. solanacearum was introduced by transplanting two root-inoculated plants, significantly move plants developed wilt at pH $6{\cdot}5$(34 out of 48 plants) than at pH 5.0(11 out of 48 plants). In addition, when the bacterium was introduced by transplanting two stem-inoculated plants at pH $6{\cdot}5$, seven out of 24 plants developed wilt.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.375-383
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• 2009

This study was carried out to develop transgenic rice cultivars with the CAX1 (accession no. U57411) gene. We successfully selected the transgenic rice plants over-expressing the Arabidopsis H+/$Ca^{2+}$ antiporter CAX1 (accession no. U57411) gene in T6 generation. The brown rice of the CAX1 expressing rice contained 13.4~68.0 % more calcium $(Ca^{2+})$ than that of the wild type and 5 lines were selected based on the phenotypes compared to the control cultivar at the GMO field. The CAX1 expressing transgenic rice plants were similar in phenotype to the wild type during the whole growth period. Also these selected 4 lines appeared to be resistant to blast, cold and water solution compared with the wild type. Difference in 1,000 grain weight of brown rice was observed among each line but grain shape did not show any morphological alternations. These results suggest the enhanced Ca-substrate specificity of CAX1 exchanger in donor plant. Therefore, intact CAX1 exchanger can be functionally useful for $Ca^{2+}$ nutrient enrichment of rice with reduced accumulation of undesirable cation.

• Research in Plant Disease
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• v.21 no.4
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• pp.290-296
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• 2015

This study was conducted to establish an efficient screening system for resistant tomato to bacterial wilt caused by Ralstonia solanacearum. Under several conditions such as inoculation methods, growth stages of tomato seedlings, inoculum concentrations, and incubating temperatures after inoculation, development of bacterial wilt on nine resistant or susceptible cultivars of tomato was investigated. To inoculate by drenching the non-cut roots with the bacterial suspension was better to distinguish resistance and susceptibility of tomato cultivars than by drenching the cut roots using scalpel. And 'Hawaii7996' a resistant tomato to R. solanacearum showed high resistance at all the tested conditions including growth stages (3-, 6-, 8-, 10-leaf stages), inoculum concentrations ($OD_{600}=0.1-0.4$) and incubation temperatures (25, 30, $35^{\circ}C$). On the other hands, susceptible cultivars represented disease index of 3.7 and 3.9 at 6- and 8-leaf stages, respectively. At 3- and 10-leaf stages, the cultivars demonstrated lower disease severity of 2.1 and 0.5, respectively, than at 6- and 8-leaf stages. When the inoculated seedlings were incubated in growth chambers of 25, 30 and $35^{\circ}C$, disease severity of susceptible cultivars was significantly greater at 30 and $35^{\circ}C$ than at $25^{\circ}C$. In addition, the level of resistance of the tomato cultivars was not significantly affected by inoculum concentrations of $OD_{600}=0.1-0.4$. On the basis of the results, we suggest an efficient screening method to measure resistance level of tomato cultivars to bacterial wilt. The eight-leaf stage seedlings transplanted 7 days before inoculation, are inoculated with R. solanacearum by drenching the non-cut roots with a bacterial suspensions ($OD_{600}=0.4$) to give inoculum volume of 50 ml/soil l. The inoculated plants are incubated in a growth room at $30^{\circ}C$ for 12-13 days with 12-hour light a day.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.313-319
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• 2006

Two hundred bacterial strains were isolated from the soil around healthy tomato plants in a polyvinyl house, where most of the other plants showed bacterial wilt symptoms. The strains were screened in vitro for their antibacterial activity. Among them, a strain, KPB3 showed strong bactericidal activity against bacterial wilt pathogen, Ralstonia solanacearum. The strain KPB3 was identified using physiological and biochemical tests, and 16S rRNA analyses. Based on these tests, the strain was found to be closer to genus Paenibacillus. To control the bacterial wilt caused by R. solanacearum, greenhouse experiments were conducted to determine the effectiveness of the Paenibacillus strain KPB3. Drench application of this strain ($4{\times}10^8$ CFU $mL^{-1}$) into the pots containing tomato plants, post-inoculated with the pathogen, R. solanacearum could drastically reduce the disease severity, compared to the non-treated plants. To evaluate effectiveness of this strain under field conditions, experiments were carried out in polyvinyl houses infested with R. solanacearum, during spring and autumn of the year 2006. It was observed that, during spring, bacterial wilt was more prevalent compared to the autumn. During spring, 50.9% disease incidences occurred in non-treated controls, while, Paenibacillus strain KPB3 treated plants showed 24.6% disease incidences. Similarly, during autumn, around 17.2% plants were infected with bacterial wilt in non- treated polyvinyl houses, compared to the Paenibacillus strain KPB3 treated plants, which showed 7.0% disease incidences. These results demonstrated that, Paenibacillus strain KPB3 is a potential biological control agent against bacterial wilt caused by R. solanacearum, effective under greenhouse as well as field conditions. This is the first report showing biocontrol of R. solanacearum using a Paenibacillus spp. under field conditions.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.250-255
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• 2017

'Hwaweon 7' was developed from a cross between the African upland cultivar, 'Moroberekan' and 'Ilpumbyeo' based on marker-aided backcross selection. The recurrent parent, Ilpumbyeo is a high grain quality cultivar with medium to late maturity. Hwaweon 7 is nearly isogenic to Ilpumbyeo except a small Moroberekan introgressed segment on chromosome 6 harboring genes related with spikelets per panicle and internode diameter. The preliminary and replicated yield trial was conducted at Chungnam National University and Chungcheongnamdo Agricultural Research & Extension (CARES), Yesan in 2010 and 2011. The local adaptability test was carried out by the National Seed Management Office (NSMO) in 2012 and 2013. This cultivar was registered to NSMO with a cultivar designated as "Hwaweon7". This cultivar averaged 80cm in culm length and has a medium growth duration. Milled rice of "Hwaweon7" is translucent and the grain quality traits are comparable to those of the recurrent parent. The average yield potential of Hwaweon 7 in grain was about 6.48 MT/ha at the ordinary fertilizer level for two years about 5.1% higher than that of Ilpumbyeo due to increase in spikelets per panicle. This variety is tolerant to lodging and the tolerance is due to the APO1 gene controlling the base internode diameter on chromosome 6 introgressed from the donor parent, Moroberekan. The Apo1 gene would be useful in enhancing resistance to lodging in rice breeding program.

• Korean journal of applied entomology
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• v.18 no.2 s.39
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• pp.73-76
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• 1979

Two different isolates of Xanthomonas oryzae, KB 7785 of pathotype I and JN 7721 of pathotype III, that had been the most virulent isolates in the previous inoculation test, were reisolated from cultivar 'Milyang 23' and serially transferred to 10 times. They were inoculated to the 3 cultivars; 'Milyang 23' in Kinmaze group, 'Yushin' in Kogyoku group and 'Tongil' in Rantai-emas group cultivars. It was observed that the virulence of the isolate JN 7721 was more attenuated by the serial transfer on the Wakimoto's agar than the isolate KB 7785. The attenuation of virulence of the isolate JN 7721 was more significant at the cultivar 'Milyang23' than at the other cultivars. This suggests that the host-pathogen interactions and differences of the pathogenicity-maintenance ability among the pathogenic strains may be involved.