• Journal of Plant Biotechnology
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• 제47권4호
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• pp.337-344
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• 2020

식물생장촉진 미생물은 식물 뿌리에 영양을 원활하게 공급하거나 휘발성 유기화합물(Volatile Organic Compound, VOC)를 이용하여 식물의 내재 인자와 상호작용을 통해 생장을 촉진한다. 본 연구에서는 식물 생장 촉진 진균 UOS의 담배에서의 생장 촉진 효과를 평가하고, 계통발생학적 분석을 통해 동정하였다. 또한, UOS의 식물 생장 촉진 인자를 탐색하고자 Gas Chromatography-Mass Spectrometry (GC-MS) 분석을 통해 UOS의 VOCs를 확인하였다. UOS를 처리한 담배는 무처리구에 비해서 3.8배의 생중량이 증가하였고, I-plate를 이용한 분리된 공간에서는 UOS처리구가 무처리에 비해 생중량이 4.2배 증가하였다. 또한, UOS 처리구의 식물은 주근의 길이가 약2배 짧아지고 측근의 수가 약2배 증가하였다. UOS은 포자 및 균사 형태와 Internal transcribed spacer (ITS) 유전자 염기서열을 통하여 Phoma sp.으로 동정되었으며, 이들은 GC-MS분석을 통해 UOS는 hexamethylcyclotrisiloxane (D3)라는 VOC를 갖고 있는 것이 밝혀졌다. 이 결과들은 Phoma sp.의 진균 UOS가 VOC물질인 D3을 통해서 간접적으로 식물 생장 촉진 및 뿌리 발달에 영향을 미치는 것을 나타낸다. UOS와 그의 VOC인 D3의 활용은 농업에서 생장량 증대에 기여할 것으로 판단된다.

• 한국작물학회지
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• 제27권4호
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• pp.361-370
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• 1982

The effects of climatic factors on organisms lire variable and complex, and it, however, can be interpreted in terms of those on the distribution and those on the population densities. The distribution of an organism may largely be determined by the temperatures, except some temporal organisms which are depended on the air mass movements. Population density of an organism is determined by various climatic factors, such as previous winter temperature, temperature of growing season and rainfall. The start of growing season of the rice plants has been shifted to earlier since last decade in Korea. This may mean that the overall climatic condition during the growing season might be considerably different from those in past years, and such a difference in climatic conditions might have close relation with the recent status of the diseases and insect pests through direct effects on the physiology and population dynamics of the organisms, as well as through on the biotic associations of the pest organisms. The white back planthopper and brown planthopper have become the key insect pests in Korea in recent years. They are migratory and have high reproductive pontentials and more generations than average residential insects. The synchronization of the migrants and physiological condition of the rice plants seems to be the important factors in relation to the recent outbreaks of these insects; the high reproductive rate can be obtained with the growth stage of rice being 30-50 days after transplanting. The modication of the microclimate associated with high plant density and some other introduced new cultural techniques also have some relation with the outbreak. The key diseases of the rice are the blast disease, sheath blight and the bacterial leaf blight. For the rice blast, the seedling blast and leaf blast during the early growing season and the neck blast, have become more serious, the former may be related to hotbed nursery and the later may be related to the high humidity in early August, and synchronization of the heading time which has been shifted to early part from middle or late part of August. In general, for the rice diseases, the development of the new races have been the most serious which are largely resulted from the introduction of the new varieties, but it also seems to be related with the prolonged periods of the favorable condition associated with the shifted growing seasons. In general, the diseases and insect pest problems have become much more variable and complex, and control measures should be based on the thorough knowledge of the ecology of the pest organisms, that is, effects of various environmental factors on the disease cycle; spore release, spore deposition, infection, colonization and sporulation of the disease organisms, and those on the development, reproductive potentials, dispersal, age specific responses of the insects. The well organized real-time pest management systems, such as alfalfa weevil management system developed at the Purdue University in U.S., is the prime importance for the implementation of the pest management principles.

• Journal of Forest and Environmental Science
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• 제36권3호
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• pp.207-218
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• 2020

Ashwagandha is an important ancient medicinal crops, being affected with many diseases, among which leaf blight caused by Alternaria alternata has become the constraint resulting in huge yield losses. Continuous usage of chemical methods leads to environment, soil and water pollution. Whereas biological control of diseases is long lasting, inexpensive, eco-friendly and harmless to target organisms. In this context, it is aimed to evaluate five Trichoderma strains viz. Trichoderma virens IMI-392430, T. pseudokoningii IMI-392431, T. harzianum IMI-392432, T. harzianum IMI-392433 and T. harzianum IMI-392434 as bio-control efficacy against A. alternata and growth promoting effect in Ashwagandha. All the Trichoderma strains had varied antagonistic effects against the pathogen. In dual culture technique, the strain T. harzianum IMI-392433 showed maximum percentage inhibition of mycelial growth (54.89%) followed by T. harzianum IMI-392432 (53.83%), T. harzianum IMI-392434 (48.94%) and T. virens IMI-392430, (43.62%) against the pathogen, while the least inhibition percentage was observed with the T. pseudokoningii IMI-392431 (36.60%). The culture filtrate of the Trichoderma strain, T. harzianum IMI-392433 recorded highest inhibition on the mycelial growth (39.05%) and spore germination (80.77%) of pathogen and the lowest was recorded in T. pseudokoningii IMI-392431 (20.45 and 50%). Moreover, seeds treated with spore suspension of the strain T. harzianum IMI-392433 reduced the percentages of disease severity index significantly. The strain T. harzianum IMI-392433 also significantly increased seed germination %, seedling vigor and growth of Ashwagandha. The correlation matrix showed that root yield per plant of Ashwagandha had significant and positive correlation with plant height (r=0.726^⁎⁎), number of leaf (r=0.514^⁎⁎), number of primary branch (r=0.820^⁎⁎), number of secondary branch (r=0.829^⁎⁎), fresh plant weight (r=0.887^⁎⁎), plant dry weight (r=0.613^⁎⁎), root length (r=0.824^⁎⁎), root diameter (r=0.786^⁎⁎), root dry weight (r=0.739^⁎⁎) and fresh root weight (r=0.731^⁎⁎). The significant and negative correlation (r=-0.336^⁎⁎) was observed with the root yield and percentages of disease severity index. The study recognized that the T. harzianum IMI-392433 strain performed well in inhibiting the mycelial growth and reduced the percentages of disease severity index of pathogen as well as increased the plant growth in Ashwagandha.

• 한국토양비료학회지
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• 제43권3호
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• pp.384-389
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• 2010

Outbreak of contagious diseases to livestock animals is becoming prevalent worldwide and consequently, tremendous numbers of the infected or culled stocks are buried on the ground as the most common disposal method. The buried animals can generate a wide range of detrimental components such as leachate, nutrient salts, and pathogenic bacteria, consequently contaminating the surround environment. This implies that regular investigations are required to monitor any possible detrimental environmental aspect occurred around burial sites. Therefore, the current study was conducted to investigate whether the soil and groundwater nearby the burial sites had been contaminated by the substances originated from the burial sites, which can be applied for the establishment of the ideal burial site construction design and post management scheme. For this, two different burial sites located in Cheonan and Pyeongtaek were selected. Cheonan and Pyeongtaek sites were constructed in 2004 and 2008, respectively and both contained dead poultry infected by avian influenza (AI). Soil and groundwater samples were collected around the sites followed by determination of the nutrient concentrations and bacteria (Salmonella, Camphylobacter, and Bacillus) existence in both soil and groundwater. Some of the soil samples showed higher EC, $NH_4$-N, $NO_3$-N concentration compared to those of the background (control) soils. Also the concentration of $NH_4$-N in some of the groundwater samples appeared to exceed the USEPA guideline value for drinking water (10 mg $L^{-1}$). These results indicated that the soil and groundwater were influenced by the burial site originated nutrients. In the soil, Bacillus was isolated in most soil samples while there were no detections of Salmonella and Camplylobacter. Due to the Bacillus existing mainly as a spore in the soils, it was considered that the frequent detection of Bacillus in the soil samples was attributed to the nutrients originated from the burial sites.

• 한국환경보건학회지
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• 제21권3호
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• pp.48-55
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• 1995

This study was performed to investigate the inhibitory effect of Aloe vera on the growth and aflatoxin production of Aspergillus parasiticus. Spore suspension of A. parasiticus ATCC 15517 was inoculated on the yeast-extract sucrose broth containing 0.1%, 0.5%, 1.0% and 10.0% of chloroform extract of Aloe vera and then incubated at 30$\circ$C for 7 days. Mycelial weight was 160.7 mg/5ml in control group and decreased by the addition of the extract with no significance. The mold caused decrease in pH of the media with and without the extract. pH in the group contained 10.0% of the extract showed significantly higher value of 5.10 than that of 4.90 in control group (p<0.05). Fluorescence spots of four aflatoxins were observed under the 365 nm of UV light after extraction of the media and TLC. In the result of separation and determination by HPLC, the aflatoxins were produced in the order of $B_1, G_1, B_2$ and $G_2$ in all groups. Production of aflatoxins $B_1, B_2$ and $G_1$ was reduced by the addition of the extract and decreased as amount of the extract increased. The production of aflatoxins $B_1$ and $B_2$ significantly reduced when the media contained more than 1.0% of the extract, and $G_1$ more than 0.5%, respectively(p<0.05). No reduction and no significant difference among groups were observed in case of aflatoxin $G_2$. With the above result, the extract of Aloe vera reduced the production of aflatoxin by A. parasiticus though it did not inhibit mycelial growth.

• 한국환경복원기술학회지
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• 제6권1호
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• pp.41-50
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• 2003

The feasibility as floricultural crops and water garden plant materials of Korean native water plants was investigated. Propagation type, growing and flowering time were observed for development as water garden, interior aquarium plant and water purification materials. Flowering time of the water plant was 7 species in May, 28 species in June, 49 species in July, 55 species in August, 47 species in September, and 17 species in October. Beautiful flowering water plants were Nymphaeaceae, Nymphoides peltata, Nymphoides indica, Monochoria korsakowii, Iris pseudacorus, Iris laevigata, and etc. Ornamental leafy water plants were Ceratopteris thalictroides, Ludwigia ovalis, Myriophyllum verticillatim, Limnophila sessiliflora, Blyxa aubertii, Blyxa echinosperma, Vallisneria asiatica, Hydrilla verticillata and Eleocharis acicularis etc. Isoetes japonica, Isoetes coreana and Isoetes sinensis were propagated by spore. Blyxa aubertii, Blyxa echinosperma, Myriophyllum verticillatim, Nuphar japonicum, Nelumbo nucifera, Ottelia alismoides, Sagittaria aginashi, Trapa japonica, and Trapa natans were propagated by seed. Persicaria amphibia, Ceratophyllum demersum (hornwort), Myriophyllum verticillatim, Myriophyllum spicatum, Oenanthe javanica, Potamogeton crispus, Hydrilla verticillata and Acorus calamus were propagated by division. And Vallisneria asiatica, Hydrilla verticillata and Phragmites japonica were propagated by runner. Ceratophyllum demersum (hornwort), Myriophyllum verticillatim, Myriophyllum spicatum, Limnophila sessilifera were propagated by adventitious bud. Ceratopteris thalictroides was propagated by leaf cutting. The 35 genera, 68 species of water plants were available for horticultural use. The 45 species such as Iris laevigata, Eleocharis acicularis, Menyanthes trifoliata, Nymphaea minima, Nuphar pumilum, Nymphoides coreana, Nymphoides peltata, Nymphoides indica, Nymphaea tetragona (water lily), and Typha latifolia could be use for water garden plant. The 21 species such as Limnophila sessilifera, Vallisneria asiatica, Ceratophyllum demersum and Hydrilla verticillata available for indoor aquarium. The 19 species such as Ottelia alismoides, Oenanthe javanica, Limnophila sessilifera and Blyxa echinosperma could be culture in container. The 27 species such as Trapa japonica, Trapa incisa, Phramites commuris (reed), Phragmites japonica, and Zizania latifolia were usable for water purification plant materials.

• 한국환경농학회지
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• 제13권3호
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• pp.301-310
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• 1994

50종의 약용식물추출액을 공시하여 흰가루병에 대한 방제효과를 검정하고 생리활성 물질을 분리, 동정하였다. 공시약용식물중에서 대황의 물추출액은 200배의 희석농도에서도 100%의 포자발아억제 효과를 나타내서 가장 효과가 있었고, 대황의 물추출액 50배, 알콜추출액 100배, 조물질 500배, 표준품 1000배 희석농도까지도 60%이상의 발병억제효과가 있었으며, 조물질 500배액에서 2회 이상 살포하면 100% 발병억제 효과가 있었다. 그리고 조물질 100배 액에서는 약해가 있었으나 500배액에서는 약해가 없었다. 대황에 함유되어 있는 생리활성물질은 anthraquinone유도체인 1,8-dihydroxy-3-methyl-9,10-anthracenedione과 1,8-dihydroxy-3-methoxy-6-methyl-9,10-anthracenedione으로 잠정 동정되었다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권6호
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• pp.922-934
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• 2010

바다숲 조성용 시설물의 효율적인 배치를 위하여 수치실험을 통하여 바다숲 조성 예정지의 조석류에 의한 해수흐름을 분석하였으며, 분석된 해수흐름을 바탕으로 하여 해조포자의 거동을 파악하기 위하여 입자추적실험을 수행하였다. 수치실험에 사용된 수치모형은 EFDC(Environmental Fluids Dynamics Code)를 사용하였으며, 연직방향으로 총 5개 층으로 나누어 실험을 수행하였다. 실험결과, 바다숲 조성대상해역의 해수흐름패턴은 대상해역 바깥쪽의 주류에 크게 영향을 받고 있음을 알 수 있었고, 잔차류를 분석한 결과 크게 두 개의 순환 고리가 형성되어 있음을 확인하였다. 해수흐름의 패턴을 고려하여 3곳의 바다숲 시설물의 설치장소를 선정하고 저층에 입자를 투입하여 15일간 추적을 실시한 결과, 1번과 3번 정점은 해안선에 연하여 띠형태로 시설하며, 2번 정점은 연안에서 약 300 ~ 500m정도 떨어진 곳에 타원의 형태로 시설하는 것이 보다 효율적일 것으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1874-1883
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• 2008

Bacterial diversity and the composition of individual communities during the composting process of swine and mushroom cultural wastes in a field-scale composter (Hazaka system) were examined using a PCR-based approach. The composting process was divided into six stages based on recorded temperature changes. Phylogenetic analysis of eighty 16S rRNA sequences from uncultured composting bacterial groups revealed the presence of representatives from three divisions, including plant pathogenic bacteria, high-molecule-degrading bacteria and spore-forming bacteria. The plant pathogen A. tumefaciens gradually decreased in abundance during the composting process and eventually disappeared during the thermophilic and cooling stage. A bacterium homologous to Bacillus humi first appeared at the early thermophilic stage and was established at the intermediate thermophilic, post-thermophilic, and cooling stages. It was not possible to isolate the B. humi during any of the stages using general culture techniques.

• 한국물환경학회지
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• 제22권2호
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• pp.271-276
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• 2006

The outbreak cases of Cryptosporidium or Giardia from drinking water in abroad have drawn attentions on the public health. It is well known that Cryptosporidium is the most resistant organism against chlorine disinfection. To guesstimate the levels of Cryptosporidium and Giardia in Korean surface water, 1~2 samples from 22 drinking water sources in four Korean major rivers of Han, Keum, Nakdong, and Youngsan were monitored. In addition, two sites in Kyunganchon, a contaminated river were monitored for comparison. In source waters, detection rates of Cryptosporidium and Giardia were 15% (6/39) and 21% (5/24) with the range of 1~3 oocysts/10 L and 1~6 cysts/10 L, respectively. In Kyunganchon, they were 60% (6/10) and 70% (7/10) in the range of 1~9 oocysts/10 L and 10~72 cysts/10 L, respectively. When one of the source waters in Han river was monitored monthly, Cryptosporidium were found mostly in cold season. Matrix of the samples gave influence on the recoveries of the spiked protozoa. The recoveries of both Cryptosporidium and Giardia increased in the samples of Kyunganchon, known as contaminated area. However, protozoan recovery did not show significant relation with turbidity, the index of matrix contamination, which implies that there are additional unveiled features of matrix affecting the recoveries of the protozoa. The protozoan distribution in Kyunganchon showed significant relations with Cl. perfringens, anaerobic and spore forming indicator bacteria of fecal contamination by regression analysis, but not with turbidity, the general indicator of water quality.