• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.112.2-112
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• 2003

Levels of blister rust infection (from Cronartium ribicola) varied in western white pine(Pinus monticola Dougl.) seedlings grown in two nurseries in northern Idaho. This observation suggested the potential importance of environmental components operating on the blister rust pathosystem. In an experiment designed to test the influence of environmental conditions at two nurseries, seedlings of a single genetic source were unintentionally held in cold storage for 6 months longer at one nursery than at the other. Subsequently, these seedlings, which had been growing under nursery conditions for 7 months or 1 month, were inoculated with blister rust spores on September 9th, 1999. Infection efficiency measured on the seedlings with only 1 month of growth was 70X greater than on the seedlings that had 7 months for their new growth to mature. Results from this nursery test and infection levels of northern Idaho resistant selections in mild climates suggest that expression of genes related to rust resistance in western white pine can be manipulated by regulation of phonology. If so, several new molecular tools may be employed to enhance our understanding of environmental regulation of genes for blister rust resistance.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.139-143
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• 2001

The efficacies of several entomopathogenic nematodes of Steinernema and Heterorhabditis spp. were examined against tobacco cutworm, Spodoptera litura Fabricius. H. bacteriophora HY showed 100% mortality after 20 h against 2nd instar of tobacco cutworm. In the case of 3-4th instar, S. carpocapsae PC, H. bacteriophora HY and S. monticola CR showed 100% mortality after 47 h. In the case of 5-6th instar, S. carpocapsae PC proved more effective than the others. Generally, the number of nematodes harvested as their size decreased. Also, the highest number of nematodes was obtained in the 5-6th instar of S. litura by H. bacteriophora HY, showing about $1.3{\times}10^6$ nematodes per larva. In vitro cultured S. carpocapsae PC showed 100% mortality after 73 h against 5-6th instar tobacco cutworm, indicating that nematodes produced in vitro can be potentially used for the biological control of S. litura instead of nematodes in vivo.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1210-1217
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• 2021

Two gram-negative, catalase-positive, strictly aerobic, and white colony-forming bacteria, strains H242^T and B156^T, were isolated from soil in South Korea. Cells of strain H242^T were oxidase-positive and non-motile short rods, while those of strain B156^T were oxidase-negative and long non-motile rods. Ubiquinone-8 was identified as the sole isoprenoid quinone in both strains. C_16:0, cyclo-C_17:0, andsummed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol were identified in both strains as the major cellular fatty acids and polar lipids, respectively. The DNA G+C contents of strains H242^T and B156^T were 69.4 mol% and 69.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA and 92 concatenated core gene sequences revealed that strains H242^T and B156^T formed distinct phylogenic lineages from other Ramlibacter type strains. The DNA-DNA hybridization (DDH) value between strains H242^T and B156^T was 24.6%. Strains H242^T and B156^T were most closely related to Ramlibacter ginsenosidimutans BXN5-27^T and Ramlibacter monticola G-3-2^T with 98.4% and 98.6% 16S rRNA gene sequence similarities, respectively. Digital DDH values between strain H242^T and R. ginsenosidimutans and between strain B156^T and R. monticola were 23.5% and 26.1%, respectively. Phenotypic, chemotaxonomic, and molecular analyses indicated that strains H242^T and B156^T represent two novel species of the genus Ramlibacter, for which the names Ramlibacter terrae sp. nov. and Ramlibacter montanisoli sp. nov., respectively, are proposed. The type strains of R. terrae and R. montanisoli are H242^T (=KACC 21667^T=JCM 33922^T) and B156^T (=KACC 21665^T=JCM 33920^T), respectively.

• The Korean Journal of Soil Zoology
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• v.1 no.1
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• pp.28-36
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• 1996

A survey for entomopathogenic nematodes was conducted throughout the nine provinvrd and within three city limits during the summer of 1990 and 1991. Six of the nine provinces and one of the three cities were positive for entomopathogenic nematodes. Out of the total 499 soil samples, 23(4.6%) were positive for entomopathogenic nematodes with 19(3.8%) containing Steinernema and 4(0.8%) containing Heterorhabditis. Heterorhabditis bacteriopora and three distinct groups of Steinernema species were idintified. One groups was indentified as S. carpocapsae, another S. glaseri and the other S. monticola based on cross breeding studies. Positive sample sites in each habitat includes 15 of the 415(3.6%) from forests including regrowth areas with shrubs, 1 of the 27(3.7%) from turfgrass including golf courses and parks, 3 of the 24(12.5%) from agricultural fields, 2 of the 16(12.5%) along riparian areas, and of the 17(11.8%) near the seashore. We advocate that more surveys be conducted for entomopathogenic nematodes before commercial sources of nematodes are widely applied which may obscure the naturally-occurring nematodes. A key to Steinernema is provided for the identification.

• Asian Journal of Turfgrass Science
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• v.12 no.2
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• pp.127-140
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• 1998

곤충병원성 선충의 이용 효율을 높이기 위하여 곤충병원성 선충 상호간 또는 선충과 곤충병원성 곰팡이와의 상호관계를 알아보았다. Steinernema glaseri는 기주의 무게에 따라 성충수에서는 차이가 없었으나 침입태 유충수에서는 차이가 있었다. 선충의 접종 농도에 따른 침입 발육된 성충수는 기주당 20마리 이하의 접종에서는 차이를 보였으나 40마리 이상 1,000마리 접종구에서는 차이가 없었고, 증식된 유충수도 기주당 1,000마리 접종구에서 현저히 적은 것을 제외하고는 차이가 없었다. 동일 기주에서의 선충 상호간 관계에서는 steinernematid 선충에 의한 기주 치사율이 heterorhabditid 선충에 의한 것보다 높았다. 즉, 서로 다른 종의 곤충병원성 선충을 동일 기주에 접종하였을 때, S. carpocapsae 포천에 의한 기주 치사율은 $76.2\pm$4.8%였고 Heterorhabditis bacteriophora 함양에 의한 치사율은 $23.8\pm$4.8%였다. 또한 S. carpocapsae 포천에 의한 기주치사율이 각각 $90.5\pm$4.8%와 $80.9\pm$4.8%, H. bacteriophora NC 1에 의한 것은 9.5$\pm$4.8%였다. S. glaseri NC와 H. bacteriophora 함양 및 H. bacteriophora NC 1을 동시 접종하였을 때는 S. glaseri NC에 의한 것이 각각 $61.9\pm$9.65%와 $80.9\pm$4.8%, H. bacteriophora 함양에 의한 것이 $38.1\pm$9.5%, H. bacteriophora NC 1에 의한 것이 $19.1\pm$4.8%였다. 그러나 두 선충의 동시 감염은 관찰되지 않았다. 그리고 S. carpocapsae All과 곤충병원성 곰팡이인 Beauveria brongniartii를 동시 또는 곰팡이를 먼저 처리했을 때는 곰팡이 12시간 전 처리부터 선충과 곰팡이의 동시 감염이 관찰되었고, H. bacteriophora NC 1는 곰팡이 6시간 전 처리부터 동시 감염이 관찰되었다. 선충에 의한 감염과, 곰팡이에 의한 감염, 선충과 곰팡이 동시 감염은 곰팡이 48시간 전 처리부터 관찰되었다. 그러나 유충 증식수는 선충 단독 감염보다 동시 감염충에서 현저히 떨어졌다.