• The Korean Journal of Mycology
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• v.41 no.3
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• pp.149-159
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• 2013

The nitrogen source-requirement and preference of ectomycorrhizal fungi (42 strains belong to 13 genera) collected from Korean forests were investigated by incubating mycelial cells in four nitrogen source test media for 56 days. The nitrogen requirement was relatively high in five strains (Heimioporus japonicas (KFRI 1224), Suillus luteus (KFRI 1232), Tylopilus castaneiceps (KFRI 1383), Suillus granulates (KFRI 1997), Rhizopogon sp. (KFRI 1434)) in comparison with other strains. Forty-five percent of ectomycorrhizal strains including Boletus griseus (KFRI 1362) preferred the ammonium-form of inorganic nitrogen source for mycelial growth, whereas thirty-six percent of tested strains including Suillus grevillei (KFRI 1125) preferred the nitrate-form as an inorganic nitrogen source.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.127-127
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• 2003

벼 도열병 저항성 조절과정을 연구하는 효율적인 방법은 돌연변이를 분리하여 해당유전자를 분석하는 것이다. 이를 위하여 벼에서 제조된 4가지 돌연변이 집단을 이용하여 도열병 저항성 돌연변이를 분리하였다. 실험재료로는 1) fast neturon을 처리하여 제조된 Moroberekan 2,000 라인, 2)T-DNA의 형질전환에 의해서 제조된 화영 1,000 라인, 3)DEB처리에 의해서 제조된 RIL260 3,000라인, 4) gamma ray 처리에 의해서 제조된 상해향혈나 10,000 라인 등이 사용되었다. 병 저항성이 감소된 돌연변이의 분리를 위하여 재료로 사용된 벼 품종과 비친화적 상호작용을 보이는 균주의 포자를 2-3주된 벼 잎에 직접 살포하는 방법을 이용하였다. 균주 접종 7 일 후에 blast lesion을 형성하거나 lesion mimic 표현형을 보이는 돌연변이 등 병저항성이 감소된 라인을 선별하였다. 현재까지 1) Moroberakan 5 라인, 2) 화영 4 라인, 3) RIL260 1 라인 등이 선별되었다. 이와 함께 병저항성이 현저히 증가된 돌연 변이를 선별하기 위하여 친화적인 균주를 사용한 실험에서는 상해향렬나 2 라인이 선별되었다. 선별된 돌연변이는 벼 도열병 저항성 유전자의 분리 및 저항성 조절기작을 연구하는데 효과적으로 사용될 것이다.

• The Journal of Natural Sciences
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• v.12 no.1
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• pp.69-79
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• 2002

850 strains of phosphate-solubilizing bacteria were isolated from soil of Chung-nam and Daejeon region using 0.5% calcium phosphate containing medium. The HS-2 strain with the highest rock phosphate-solubilizing activity was selected and identified as Azotobacter sp. HS-2 based on the microbiological characteristics. The optimum culture temperature and initial pH of medium for solubilization of rock phosphate were $30^{\circ}C$ and pH 6.0-7.0, respectively. Addition of oxalic acid(0.5M) into the PDB-rock phosphate medium increased 50% solubilization of rock phosphate.

• KSBB Journal
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• v.16 no.3
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• pp.286-289
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• 2001

A beterotrophic Pseudomonas putida B2 was used to treat of hydrogen sulfide containing gas. The experimental approach involved operating two indentical bench-scale biofilters with media consisting of a mixture of peatmoss, perlite and granular activated carbon(GAC). One column was seeded with Pseudomonas putida B2 and the other was left unseeded. The biofilter was operated for 16 days under EBRT for 20-40 sec, at a temperature of 25-30$^{\circ}C$ and a hydrogen sulfide concentration of 40-190 ppm. The biofilter inocculated with P.putida B2 exhibited high hydrogen sulfide removal efficiency, average of 95%, at a gydrogen sulfide concentration of 40-190 ppm (flow rate 3.6 L/min). However, at a shock loading of 190 ppm the biofiter showed a removal efficiency of 78.9% and the control only showed a removal efficiency of 31.6%. The critical load of this biofilter was 14.83 g/㎥hr, and the critical load of the control column was 4.93 g/㎥hr. These results suggest that P. putida B2 has the potential to be used as a $H_2S$ removal agent in a biofilter.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.4
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• pp.333-342
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• 2010

Corn is very important forage in Korea. The great part of them is utilized as silage. Generally, it contains a lot of grains that is feed of animal. This experiment was conducted to evaluation of fermentation ability of microbes for corn silage inoculant. Good lactic acid bacteria were isolated from good corn silage by plating MRS agar containing 0.02% sodium azide, and assessed by growing and acid producing ability in MRS broth. Six lactic acid bacteria were selected, and were found to be Gram positive, rods and catalase negative and were identified to be lactobacillus plantarum (C3-2, B13-1, CC9-1), Lactobacillus fermentum (C11-4), Lactobacillus paracasei (B14-1), and Leuconostoc lactis (A3-1) on the basis of the biochemical characteristics and utilization of substrates. Corn was ensiled at ripen stage following treatment with selected five lactic acid bacteria, two commercial inoculant, and no additive (control). After 2 month, B13-1 and CC9-1 bacteria inoculated silage were lower pH and higher lactic acid content than others treatments. The Flieg's score and grade of B13-1 and CC9-1 bacteria treated silage were higher than commercial inoculant. According to this experiment, lactobacillus plantarum B13-1 and CC9-1 strain were recommendable for good inoculant of corn silage.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.68-75
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• 1999

This study was conducted to examine the effects of Arbuscular Mycorrhizae inoculation and phosphorus application on early growth of hot pepper. Gigaspora margarita and Acaulospora spinosa were chosen for this investigation and inoculated into soils of different P levels by varying inoculation time and density. After treatment, some relevant growth responses of hot pepper were measured. Regardless of soil P levels, hot peppers treated with arbuscular mycorrhizal fungi had 5~34% more fresh weight than those untreated, but the effect of inoculation time and density was not different between two species. With decreased P levels, the infection rate and dependency of hot peppers increased. The content of P and K of AMF-inoculated hot peppers increased with increasing P levels, but the shoot to root ratio of those elements decreased. The results of this study showed that inoculation of AMF would be effective in promoting growth of hot pepper seedlings and increase transplant adaptation due in part to the resulted higher root development.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.288-294
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• 1997

In order to obtain a basic information related to the utility of Sinorhizobium fredii for field soybean, the effectiveness and competitiveness of nine fast-growing S. fredii strains including TAL 1871 etc. were examined on eleven Korean soybean(Glycin max L.) cultivars. Nine S. fredii strains all modulated soybean cv. Kwangkyo, but did not Danyeobkong. The averaged shoot dry weight by S. fredii strain TAL 1781, TAL 1840, TAL 1899 marked only about 53% as compared to that by Bradyrhizobium japonicum strain YCK 213 and USDA 110. The shoot dry weight by S. fredii strains, of which TAL 1781 was the most effective in that, was increased by coinoculation with B. japonicum YCK 213 rather than with B. japonicum USDA 110. Nodule occupancy by S. fredii ranged from 8.3 to 26.7% in coinoculation with B. japonicum YCK 213, but did from 10.0 to 30.0% with B. japonicum USDA 110. These results indicated that S. fredii strains were inferior effective and competitive to B. japonicum strains.

• Research in Plant Disease
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• v.29 no.1
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• pp.1-10
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• 2023

The establishment of a laboratory assay and a greenhouse assay was conducted for evaluating the pathogenicity of Macrophomina phaseolina causing soybean charcoal rot established. In the laboratory assay, microsclerotia and hyphae were used as inoculum. In the laboratory assays using microsclerotia as an inoculum, disease incidences of M. phaseolina NSW17-108 and HSM17-034 were higher at 35℃ than 25℃. Of the two isolates NSW17-108 and HSM17-034, the disease incidence of HSM17-034 isolated from diseased sesame is higher than that of NSW17-108 isolated from diseased soybean. When the mycelia of M. phaseolina were used as an inoculum, the disease incidence of NSW17-108 and HSM17-034 at 35℃ exceeded 80% even after only 5 days of inoculation. Even at 25℃, furthermore, that of HSM17-034 exceeded 80% 5 days later. In the pathogenicity assays at a greenhouse, toothpicks where microsclerotia were produced or microsclerotia harvested from potato dextrose agar medium were used as an inoculum. In all greenhouse assays, M. phaseolina NSW17-108 and HSM17-034 showed 40-60% of disease incidences 35-65 days after inoculation with the pathogen, depending on the inoculation method. Between the two isolates, the pathogenicity of HSM17-034 was stronger than that of NSW17-108, and this result was consistent with laboratory assay results. Since the laboratory and greenhouse test methods tested in this study have different advantages and disadvantages depending on each test method, it is thought that the test method that can meet the purpose of the study should be selected and used.

• Korean Journal of Plant Resources
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• v.30 no.5
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• pp.542-548
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• 2017

Two different races of Botryris cinerea were selected by the response of plant leaves to the pathogen infection. Based on lesion size of the pathogen on the leaves, turnip showed susceptible response to 'Grape-01' race, and resistant to 'Orange' race. Turnip leaves infected with resistant pathogen race, "Orange", showed significantly higher content of indole-3-ylmethyl glucosinolate (I3M) than those infected with susceptible race, 'Grape-01'. Contents of I3M in the leaves with resistant 'Orange' race was 2.5 times as high as that in uninfected leaves, whereas I3M in the leaves infected with susceptible 'Grape-01' race showed lower content than in untreated leaves. Growth of turnip suspension cells was significantly inhibited by the treatment of MeOH extract or water extract of 'Orange' race as compared with the treatment of susceptible race, 'Grape-01'. Treatment of MeOH or water extract from 'Orange' race to turnip suspension cells, strongly inhibited cell viability up to 22.7% or 16.5%, respectively. However, plant cells treated with MeOH or water extract from resistant race, 'Orange' showed higher I3M content than that from susceptible race, 'Grape-01'. These results suggest that accumulation and degradation of I3M glucosinolate in turnip cells closely related to the resistance and susceptibility of turnip cells to Botrytis cinerea.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.261-265
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• 2000

To develope the enhanced bacterial strains capable of biodegradation for various chlorinated aromatic compounds, 100 bacterial strains were isolated from soil samples of suburbs of Taejon, Cheongju, and Jeonju by the enrichment culture. These strains can degrade pentachlorophenol (PCP) which is a kind of wood preservatives. Nineteen strains of the isolates were selected by fast colony-forming rate on solid minimal media containing PCP as an only source of carbon and energy. These strains were identified to genus level. Fifteen strains were identified as Pseudomonas, 1 strain as Acinetobacter and 3 strains were not. Genus Alcaligenes strains were not found among them. Pseudomonas sp. MU135. MU139, MU163 and MU 184 were able to degrade for 4 kinds of chlorinated compounds, PCP, 2,4-D, MCPA and 3CB. Pseudomonas sp. If was observed that MU139 exhibits the highest degradability in liquid minimal media at 72 hours after inoculation. Pseudomoans sp. MU147, MU177, MU184 and MU192 also degraded the compounds at higher rates. As the results, Pseudomonas sp. MU139 and unidentified strain MU184 had biodegrability for broad range of chlorinated compounds and higher rates of degradation for PCP.