• Title/Summary/Keyword: 생물농약

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Characteristics of δδ-Endotoxin Protein Produced from Bacillus thuringiensis subsp. kurstaki KB099 Isolate Showing High Bioactivity against Spodoptera litura (담배거세미나방(Spodoplera lilura)에 높은 살충활성을 나타내는 Bacillus thuringiensis subsp. kurstaki KB099 균주의 내독소 단백질 특성)

  • Jung, Sun-Young;Seo, Mi-Ja;Youn, Young-Nam;Yu, Yong-Man
    • The Korean Journal of Pesticide Science
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    • v.14 no.4
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    • pp.446-455
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    • 2010
  • The characteristics of parasporal inclusion body from Bacillus thuringiensis subsp. kurstaki KB099 isolate which is high bioactive to the tobacco cutworm, Spodoptera litura, were examined. Parasporal inclusion of B. thuringiensis subsp. kurstaki KB099 isolate showed only 1 band at 130 kDa compared with B. thuringiensis subsp. kurstaki HD-l isolate producing 2 protein bands at 130 kDa and 60 kDa from by SDS-PAGE analysis without any enzyme treatment. Also, we confirmed that gut extract of sensitive S. litura KB099 isolate had digested only 60 kDa δδ-endotoxin protein. When the digestive enzyme of sensitive insect responsible for parasporal inclusion from KB099 and HD-l isolate was treated to each of them, protein band 60 KDa of KB099 was maintained up to 12 hours but all bands of HD-l were disappeared within 6 hours. In KB099 isolate, 6 genes (Cry1Aa, Cry1Ab, Cry1Ac, Cry1C, Cry1D and Cry1I) were identified by PCR analysis. Also, CryCry mutant of KB099 isolate was investigated by phase- contrast microscope, SDS-PAGE and PCR.

Use of Pythium myriotylum MD2 to Control Weeds in Rice Paddy Fields (물달개비 병원균인 Pythium myriotylum MD2를 이용한 논잡초 방제)

  • Choi, Gyung-Ja;Hwang, In-Taek;Choi, Yong-Ho;Lee, Byung-Hoi;Kim, Heung-Tae;Kim, Jin-Cheol;Lee, Seon-Woo;Kim, Jin-Won;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.5 no.4
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    • pp.33-39
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    • 2001
  • An isolate of the indigenous fungus Pythium myriotylum was isolated from Monochoria vaginalis in Yusung, Korea in year 2000 and evaluated potential as a biocontrol agent in laboratory and greenhouse. P. myriotylum MD2 grew in a wide range of temperature regimes and the optimal growth temperature was 35C35C. The fungus was highly pathogenic to Monochoria vaginalis at 30 to 35C35C. Several weeds such as Rotala, indica, Lindernia procumbens, Ludwigia prostrata, Cyperus difformis, Scirpus juncoides, Aneilema keisak were also susceptible to the fungus, but Echinochloa crus-galli was not. The fungus affected the growth of rice seed germinated, but not to rice seedlings of 1- to 3-leaf stage. A total of 12 rice cultivars (3- to 4-leaf stage) tested showed no disease symptoms when inoculated with the fungus. Eleven crops, including Chinese cabbage, corn, soybean except wheat were immune to the infection of the fungi. These data suggest that P. myriotylum MD2 has a potential as a mycoherbicide to control weeds in paddy fields.

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Biological Control of Japanese Pine Sawyer, Monochamus alternatus (Coleoptera: Cerambycidae) using Korean Entomopathogenic Nematode Isolates (한국산 곤충병원성선충을 이용한 솔수염하늘소(Monochamus alternatus)의 생물적 방제)

  • Yu, Hwang Bin;Jung, Young Hak;Lee, Sang Myeong;Choo, Ho Yul;Lee, Dong Woon
    • The Korean Journal of Pesticide Science
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    • v.20 no.4
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    • pp.361-368
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    • 2016
  • Japanese pine sawyer (JPS), Monochamus alternatus is a vector insect of pine wood nematode, Bersaphlenchus xylophilus in Korea and Japanese pine forest. This study was to evaluate the possibility of biological control of JPS with Korean entomopathogenic nematodes (EPNs). Korean EPNs (Heterorhabditis sp. Gyeongsan, Steinernema carpocapsae GSN1, S. glaseri Dongrae and S. longicaudum Nonsan strain) were infested bate insect, Galleria mellonella in log of dead pine tree. Result showed that, S. carpocapsae GSN1 strain has the highest pathogenicity. Heterorhabditis sp. Gyeongsan and S. carpocapsae GSN1 had infested bate insect, which located in 7.5 cm depth of pine log. EPN has pathogenicity against larva and adult of JPS. Spray application of EPNs against adult of JPS, Heterorhabditis sp. Gyeongsan strain showed higher pathogenicity than S. carpocapsae GSN1 strain. EPN infested larva of JPS was detected on bark spray treatment with S. carpocapsae GSN1 strain in dead pine log that naturally infested larva of JPS however, no EPN infested JPS was detected on soaking of pine log with suspension of S. carpocapsae GSN1 strain. Though EPN had found with low efficacy against JPS but still possible to apply to control the boring insect pest as they can control log dwelling insect.

Searching of Possible Target Enzymes for Herbicide Development using Commercial Plant-Specific Inhibitors (식물 특정효소저해제의 생물활성 조사에 의한 신규제초제 작용점 탐색)

  • Hwan, In-Taek;Choi, Jung-Sup;Park, Sang-Hee;Lee, Kwan-Hwi;Lee, Byung-Hoi;Hong, Kyung-Sik;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.5 no.1
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    • pp.36-45
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    • 2001
  • This study was conducted to search new target enzymes of novel herbicide candidate. Total of 107 biochemical inhibitors reported to inhibit over than 100 different plant enzymes were purchased from commercial chemical companies. 15 inhibitors and 34 enzymes were selected by germination assay, seedling assay, wheat leaf disc assay, and whole plant assay. Among them, seven compounds of purine, phehyl-hydrazine, o-phenanthroline, oleylamine, dicyclohexylcarbodiimide, 7,8-benzoquinoline, and aminooxyacetic acid showed high herbicidal activity in the whole plant assay under greenhouse while 7,8-benzoquinone, 8-hydroxyquinoline, 2,2'-dipyridyl, and o-phenanthroline inhibited seed germination of barnyardgrass, rice, and tomato at concentrations of 1.25 to 5μM5μM. The compounds of 7,8-benzoquinoline, chlorpromazine, cyanuric fluoride, 4-methylpyrazole, oleylamine, tranylcypromine, and trifluoperazine inhibited the growth of cyanobacteria at 30 to 100μM100μM. The compounds of dicyclohexylcarbodiimide and chlorpromazine exhibited whitening effect on tile wheat leaf disc at 100μM100μM. These results suggest that the plant-specific enzyme inhibitors which have biological activities may supply the target enzyme for developing new herbicide candidate.

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Translocation of Polychlorinated Biphenyls in Carrot-Soil Systems (Polychlorinated Biphenyl의 작물-토양간 흡수 이행성)

  • Lim, Do-Hyung;Lim, Da-Som;Keum, Young-Soo
    • The Korean Journal of Pesticide Science
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    • v.20 no.3
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    • pp.203-210
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    • 2016
  • Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, found in the many environments. PCBs exerts various toxicological effects, including endocrine-disrupting activity. Most researches with these toxicants performed with soil matrix with mixtures of congeners, namely Aroclor, while the biological activities have been tested with animals. However, studies with pure congeners are limited. In this study, 5 congeners were synthesized and their fates (bioaccumulation, degradation, kinetics) were studied in carrot-soil system. The soil half-lives of biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126 were 20.2, 16.0, 11.6, 46.5, 198.0 days, respectively. In general, the longer half-lives were observed with the higher hydrophoicity of PCBs. Times, required for maxium accumulation of PCBs in carrot (Tmax) were 10-20 days for most congeners and the concentrations were 0.4-2.6 mg/kg. The concentrations of PCBs in carrot were kept as constant after Tmax, except PCB-126. The concentration ratio between carrot and soil after 90 days of treatment were 1.7, 8.1, 1.9, 1.8, and 5.9 for biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126. Because of the increase of biomass, the total residual amount of PCBs in carrots however, increased till the end of experiment. The portions of PCB-126 in carrot were 1.1% of the soil residues at 90 days after planting.

Inhibitory Effects of an Eicosanoid Biosynthesis Inhibitor, Benzylideneacetone, Against Two Spotted Spider Mite, Tetranychus urticae, and a Bacterial Wilt-causing Pathogen, Ralstonia solanacearum (아이코사노이드 생합성 저해제인 벤질리덴아세톤의 점박이응애(Tetranychus urticae)와 세균성풋마름병 세균(Ralstonia solanacearum)에 대한 억제효과)

  • Park, Ye-Sol;Kim, Min-Je;Lee, Geon-Hyung;Chun, Won-Soo;Yi, Young-Keun;Kim, Yong-Gyun
    • The Korean Journal of Pesticide Science
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    • v.13 no.3
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    • pp.185-189
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    • 2009
  • A monoterpenoid compound, benzylideneacetone (BZA), is a metabolite of an entomopathogenic bacterium, Xenorhabdus nematophila. Its primary biological activity is an inhibitor of phospholipase A2A2, which catalyzes the committed step of biosynthesis of various eicosanoids that are critically important to mediate insect immune responses. When BZA was applied to two-spotted spider mite, Tetranychus urticae, it exhibited a dose-dependent mortality in leaf-disc assay. Subsequently BZA was tested against T. urticae infesting apples in a field orchard, in which it showed a significant control efficacy, which was not statistically different with that of a commercial acaricide. BZA also had significant antibacterial activities against three species of plant pathogenic bacteria when it was added to the bacterial cultures, in which it showed the highest inhibitory activity against a bacterial wilt-causing pathogen, Ralstonia solanacearum. The bacterial pathogen caused significant disease symptom to young potato plants. However, BZA significantly suppressed the disease occurrence. This study suggests that BZA can be used to develop a novel crop protectant to control mite and bacterial pathogen.

Acute Toxicity Studies of Octachlorostyrenes for Environment Organisms (Octachlorostyrenes의 환경생물에 대한 급성독성 연구)

  • Kim, Yong-Seok;Jeon, Yong-Bae;Lee, Dae-Yong;Lee, Jue-Hwan;Lee, Kyu-Seung;Sung, Ha-Jung
    • The Korean Journal of Pesticide Science
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    • v.13 no.2
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    • pp.87-97
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    • 2009
  • Octachlorostyrene (OCS) is a persistant and bioaccumulative toxic subtance (PBTs). In this study, acute toxicity tests on algae, daphnia and fish for octachlorostyrene and its isomers were done to determine effective concentration (EC50EC50), Lethal concentration (LC50LC50), no observed effect concentration (NOEC) or lowest observed effect concentration (LOEC). As a result, NOEC on algae growth inhibition test for octacholorostyrene and 2-, 3-chlorostyrene was determined as 0.50mgL10.50mgL1, and NOEC for 4-chlorostyrene was determined as 0.13mgL10.13mgL1. NOEC on daphnia, acute immobilisation test for octachlorostyrene and 2-, 3-chlorostyrene was determined as 5.00mgL15.00mgL1 and EC50EC50 for 4-chlorostyrene was determined as 2.128mgL12.128mgL1. NOEC on Oryzias Latipes, acute toxicity test for octachlorostyrene was determined as 80.0mgL180.0mgL1 and NOEC for 2-, 3-chlorostyrene was determined as 60.0mgL160.0mgL1. LC50LC50 for 4-chlorostyrene was determined as 39.0mgL139.0mgL1 (48h) and 22.6mgL122.6mgL1 (96h).

Establishment of Pre-Harvest Residue Limit of Fungicides Pyrimethanil and Trifloxystrobin during Cultivation of Persimmon (단감 재배기간 중 살균제 pyrimethanil과 trifloxystrobin의 생산단계 잔류허용기준 설정)

  • Lee, Dong-Yeol;Kim, Yeong-Jin;Lee, So-Jung;Cho, Kyu-Song;Kim, Sang-Gon;Park, Min-Ho;Kang, Kyu-Young
    • Korean Journal of Environmental Agriculture
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    • v.31 no.1
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    • pp.45-51
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    • 2012
  • BACKGROUND: This study was carried out to establish pre-harvest residue limit of fungicides pyrimethanil and trifloxystrobin in persimmon, based on dissipation and biological half-lives of two fungicides residue. METHODS AND RESULTS: Both pyrimethanil and trifloxystrobin were extracted with acetonitrile, clean-up with NH2NH2 SPE cartridge and residue were analyzed by HPLC/DAD. Limit of Detection was 0.01 mg/kg. Average recovery were 81±1.6281±1.62, 98±1.5898±1.58 of pyrimethanil, and 91±2.9491±2.94, 98±1.2598±1.25 of trifloxystrobin at fortification levels at 0.1 and 0.5 mg/kg, respectively. CONCLUSION: The biological half-lives of pyrimethanil were 15.6 and 11.6 days at sprayed with recommended and double dosage, respectively. The biological half-lives of trifloxystrobin were 10.4 and 10.3 days at sprayed with recommended and double dosage, respectively. The pre-harvest residue limit of pyrimethanil and trifloxystrobin were recommended as 2.69 and 0.83 mg/kg for 10 days before harvest, respectively.

Functional Analysis of Bacillus subtilis Isolates and Biological Control of Red Pepper Powdery Mildew Using Bacillus subtilis R2-1 (Bacillus subtilis 균주의 기능성 분석 및 이를 활용한 고추 흰가루병 방제)

  • Kim, Yong-Ki;Hong, Sung-Jun;Shim, Chang-Ki;Kim, Min-Jeong;Choi, Eun-Jung;Lee, Min-Ho;Park, Jong-Ho;Han, Eun-Jung;An, Nan-Hee;Jee, Hyeong-Jin
    • Research in Plant Disease
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    • v.18 no.3
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    • pp.201-209
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    • 2012
  • The multi-function of 18 Bacillus subtilis isolates collected from agricultural extension centers of local government and National Academy of Agricultural Science was investigated by measuring their antifungal activities against five plant pathogens, such as Rhizoctonia solani, Colletotrichum acutatum, Fusarium oxysporum, Magnaporthe oryzae and Phytophthora capsici, phosphorus solubilization ability, production of indole acetic acid (IAA) and siderophore, and nitrogen fixation. The B. subtilis isolates showed antifungal activity against several plant pathogens and nitrogen fixation activity, and produced siderophore and IAA. They could control pepper powdery mildew (Leveillula taurica), but there was no difference in control efficacy among the B. subtilis isolates. In fields, the control efficacy of B. subtilis R2-1 (108108 cells/ml) was compared with two microbial fungicides, Q-pect and Topsid. In 2009, the control efficacy of B. subtilis R2-1 (37.7%) was lower than that of Topsid (47.6%), but higher than that of Q-pect (25.7%). In 2010, the control efficacy of B. subtilis R2-1 (83.3%) was higher than that of Topsid (67.9%). In order to elucidate mode of action of B. subtilis R2-1 for controlling pepper powdery mildew, spore germination rates of pepper powdery mildew pathogen collected on treated leaves was investigated when suspensions of B. subtilis R2-1 and two microbial fungicides (Q-pect and Topsid) were foliar-sprayed. They highly suppressed spore germination of the pathogen with inhibition values of 84.2% for B. subtilis R2-1, 97.9% for Q-pect and 94.7% for Topsid. Further study on the mass-culturing method and formulation is needed for development of a microbial fungicide.

Residual Pattern of Pesticide, Chlorfluazuron in Perilla Leaves Under Plastic House (들깻잎 재배 중 chlorfluazuron의 잔류량 변화 및 잔류분석법 시험)

  • Lee, Min-Ho;Kim, Seok-Ho;Park, Young-Guin;Jo, Gyeong-Yeon;Shin, Byung-Gon;Kim, Jong-Han;Kwon, Chan-Hyeok;Sohn, Jae-Keun;Kim, Jang-Eok
    • The Korean Journal of Pesticide Science
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    • v.11 no.2
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    • pp.106-116
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    • 2007
  • Pesticide, chlorfluazuron was subjected to determine the safety of terminal residues at the harvesting date of perilla leaves cultivated in plastic house. After the pesticide applied on a foliar spray in 2005 and 2006, leaf persistence of its residue was analysed for 10 days before leaf harvest. The degradation rate of chlorfluazuron in the leaf was 32.3 %(standard application), 43.6 %(double application) and 78.0 %(standard), 80.4 %(double) at second and tenth day, respectively, under analysis of GC/ECD in 2005. The degradation rate of chlorfluazuron in the leaf was 33.1 %(GC/ECD analyze), 34.0 %(HPLC/UVD analyze) and 77.9 %(GC/ECD), 78.4 %(HPLC/UVD) at second and tenth day, respectively, under the standard level of pesticide in 2006. The biological half-life of the chlorfluazuron residue was estimated by the regression equation calculated from daily dissipation of pesticide in the perilla leaves. The longest half-life of the chlorfluazuron residue in perilla leaves was 5.5 days. The maximum residual limit(MRL) for chlorfluazuron based on the longest half-life was estimated 2.0ppm at harvesting day, 2.5ppm at second day and 7.1ppm at tenth day before leaf harvesting of perilla.