• Title/Summary/Keyword: Polyoxin

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An Asymmetric Synthesis of (+)-Polyoxamic acid

  • Lee, Ki-Han;Oh, Chang-Young;Lee, Kee-Young;Kim, Yong-Hyun;Lee, Yiu-Suk;Joo, Jae-Eun;Ham, Won-Hun
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.362.3-362.3
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    • 2002
  • The Polyoxin complex is an antifungal antibiotics produced by Streptomyces cacaoi var. asoensis that exhibit marked and selective activity against pytopathogenic fungi. They incorporate carbamoylated dipeptides attached to the sugar moiety. Controlled alkaline hydrolysis of polyoxins result in several products. one of which has been identified as (+)-(2S. 3S, 4S)-2-amino-3. 4. 5-trihydroxypentonic acid(polyoxamic acid). A variety of chemical syntheses of polyoxamic acid have been developed over several years. (omitted)

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Effects of Types of Water Media and Concentration of Additives on Rooting and Survival of Ternstroemia japonica after Transplanting Cuttings (물배지의 종류 및 첨가물의 농도가 후피향나무 삽목묘의 발근 및 이식 후 활착에 미치는 영향)

  • Kang, Hyeon-Woo;Kim, Min-Soo;Kim, Dong-Uk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.5
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    • pp.141-152
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    • 2011
  • Cuttings based on water media are relatively low-cost and easy to manage compared to those based on soil media. Nevertheless, species that root out in water media are very few. Water-medium rooted cuttings are not widely used. In water media, the survival rate of cuttings is high, but in many cases, they only form callus while not rooting. If cuttings with callus formed in a water medium were to root and survive after being transplanted in soil, water-medium cuttings could be used as an important means of propagating landscape tree species. In this study, cuttings of Ternstroemia japonica having various reactions to water media were soaked in different types of water media. Their callus formation and rooting conditions were analyzed. The water-medium cutting swere then transplanted in soil, and conditions for their survival were examined. The study concluded: 1. Cuttings that only formed callus in water media were able to root and survive after being transplanted. 2. Cuttings with satisfactory callus formation showed more satisfactory survival conditions than those with unsatisfactory callus formation. 3. Cuttings rooted in water media showed a high survival rate of 96.6% after being transplanted. 4. Water-medium cutting of Ternstroemia japonica proved to be more effective in Late July or August than in late June. 5. Cuttings pre-treated in 50ppm-IBA for 24 hours showed better survival conditions than those that were not pre-treated inIBA. 6. Cuttings pre-treated in 50ppm-IBA for 24 hours and soaked in water media with 0.02% atonic, 0.02% polyoxin, and 0.01% polyoxin showed a rooting and survival rate of 80 to 85%. Regardless their low rooting rate, water-medium cuttings can show a high survival rate when these factors are considered: proper cutting time, plant hormone treatment, and types of water media. Accordingly, water-medium cuttings will emerge as major means of propagating landscape tree species that require small volumes of multi-species.

Effects of Fungicides on Sporulation of Apple Leaf Spot Alternaria mali Roberts (사과 반점낙엽병의 포자형성에 대한 살균제의 효과)

  • LEE Chang Un;KIM Moon Ho
    • Korean journal of applied entomology
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    • v.19 no.3 s.44
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    • pp.169-174
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    • 1980
  • Regardless of the kind of the apple orchards whether received various fungicides application or not Rovral exhibited the most efficient inhibitory effect on the sporulation of Alternaria mali with the spotted leaf disks at the recommended dose $0.5{\mu}g/ml$ as well as the lower or the higher doses. When applied at the recommended doses $0.7{\mu}g,\;0.75{\mu}g,\;and\;0.7{\mu}g/ml$ of Antracol, Dithane M-45, and Dikar, respectively, these fungicides showed complete inhibitory effects on the sporulation. At the lower levels of application, they allowed the sporulation of 10,000 to 25,000 conidia/ml. Polyoxin and Difolatan, when applied on the leaf disks from the orchard that had received the fungicides application, exhibited low effects allowing the sporulation of around 20,000 conidia/ml. On the leaf disks from the orchard that had received no fungicide application, however, both fungicides showed relatively high inhibitory effects of the sporulation. The inhibitory effects of Captan, Dakonil, and Spat on the sporulation were lower than those of the aforementioned fungicides. Bayleton was the least effective among the fungicides used in the present investigation. Benlate showed promoting effect on the sporulation of the apple leaf spot fungus rather tan inhibiting.

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Tolerance of Apple Blue Mold (Penicillium expansum) to Various Fungicides (사과 푸른곰팡이병균의 각종 살균제에 대한 내성)

  • Lee Chang Un
    • Korean Journal Plant Pathology
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    • v.1 no.2
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    • pp.128-135
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    • 1985
  • Responses to the 14 fungicides added in PSA of penicillium expansum isolated froms the four major apple growing areas in Korea were examined. Degrees of the fungal tolerance were various with little difference by area and with great difference by kind and concentration of fungicide. Fall isolates of the fungus grew at higher fungicide concentration than did the spring isolates. $ED_{50}$ and MIC to mycelial growth of genomyl, garbenda, polydong, polyoxin and thiophanate methyl were $0.1{\mu}g-41.7{\mu}g/ml\;and\;100{\mu}g-2,250{\mu}g/ml,$, respectively, indicating high fungicide effects on the fungus isolated from decayed apples in storages and infected apples in orchards with low fungal tolerance; of captafol, captan, iprodione and mancozeb were $2.6{\mu}g - 750{\mu}g/ml\;and\;638{\mu}g-40,500{\mu}g/ml$, respectively, indicating medium degree of both fungicidal effects and fungal tolerance; and of chlorothalonil, folpet, oxidong, propineb and triademefon were $27.8{\mu}g-8,354{\mu}g/ml\;and\;2,625{\mu}g-150,357{\mu}g/ml$, respectively, indicating low fungicide effects and high fungal tolerance. Fungicidal inhibitory effects on conidia formation exhibited a similar trend as on mycelial growth whereas those on conidia germination showed an opposite trend to the mycelial growth with the exception of polyoxin and triademefon.

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Insecticidal Activities and Synergism of Bistrifluron Against EPN-Resistant Strain of Diamondback Moth, Plutella xylostella (Lepidoptera: Plutellidae) (EPN 저항성 배추좀나방에 대한 IGR계 약제 Bistrifluron의 살충활성과 세 가지 협력제에 의한 살충활성 증진 효과)

  • Joo, You-Lee;Yang, Jeong-Oh;Yoon, Chang-Mann;Kim, Gil-Hah
    • The Korean Journal of Pesticide Science
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    • v.13 no.1
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    • pp.54-61
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    • 2009
  • EPN-resistant diamondback moth were tested the developmental characteristics, longevity, fecundity and synergistic effect with synergists when treated with the bistrifluron, an inhibitor of chitin synthesis. Inhibition rate of egg hatch was below at the recommended concentration (50 ppm) to the EPN-resistant strain than EPN-non selected strain, however, mortality within 24hr after hatching was showed as 50-60%. They did not show the difference between two strains. Mortality of larval instars were showed effective to two strains with no difference. Inhibition rate of emergence did not show any effect when treated with pupae. Moreover, they did not affect to the longevity and fecundity. When bistrifluron was treated at 50 ppm to the adult, however, longevity and fecundity was decreased with no difference between two strains. Bistrifluron to the EPN-resistant strain showed synergistic effect as high as 137.7 and 73.1 folds with synergist such as PBO (microsomal oxidase inhibitor) and polyoxin B (chitin synthetase inhibitor), respectively.

Tolerance of Alternaria mali to Various Fungicides (사과 반점낙엽병균(斑點落葉病菌)의 각종(名種) 살균제(殺菌劑)에 대(對)한 내성(耐性))

  • Lee, Chang-Un
    • Korean journal of applied entomology
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    • v.24 no.1 s.62
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    • pp.19-24
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    • 1985
  • Alternaria mali isolated from infected apples in storages and orchards of the four main apple growing areas of Taegu, Yesan, Jungup and Chungju in Korea was tested with various fungicides added in PSA medium. The fungal tolerance varied with little difference by orchard area and with great difference by king and concentration of fungicide. Minimum inhibitory concentration (MIC) of chlorothalonil and captafol was $100,238{\mu}g\;and\;81,000{\mu}g/ml$, respectively, showing low effects with high fungal tolerance; of iprodione and folpet was $3,285{\mu}g\;and\;3,000{\mu}g/ml$, respectively, showing moderate effects with moderate fungal tolerance; and of oxidong, polyoxin and polydong was $1,000{\mu}g,\;900{\mu}g\;and\;500{\mu}g/ml$, respectively, showing high effects with low fungal tolerance. Mycelial growth, conidia formation and conidia germination of the fungus showed a similar trend of response to the seven fungicides.

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Toxicity of Some Pesticides to Twospotted Spider Mite (Acari: Tetranychidae) and its Predator Amblyseius womersleyi (Acari; Phytoseiidae) (점박이응애(Tetranychus urticae Koch)와 긴털이리응애(Amblyseius womersleyi Schicha)에 대한 몇가지 농약의 선택독성)

  • C. G. Park;J. K. Yoo;J. O. Lee
    • Korean journal of applied entomology
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    • v.35 no.3
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    • pp.232-237
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    • 1996
  • Toxicity of 5 acaricides, 4 insecticides. and 6 fungicides to the twospotted spider mite, Tetranychus urticae Koch, and its predator Amblyseius womersleyi Schicha was assessed in a laboratory using a leaf disk bioassay. Dicofol was equally very toxic to aduly females of T. urticae and A. womersleyi, and caused 46% and 40% mortality of eggs of those two species, respectively. Adult females of A. womersleyi dipped in Abamectin solution showed low mortality(16.6%), while all T. urticae females died within 24 hours after dipping. Three ovicidal acaricides (Tetradifon, Clofentezine, and Hexythiazox) showed no mortality of predator eggs, but more than 90% mortality of T. urticae eggs. Four insecticides (Teflubenzuron, Triflumuron, Diflubenzuron, and Imidacloprid) and three fungicides (Propineb, Fenarimol, and Polyoxin-B captan) were non toxic to the A. womersleyi adult females. The other fungicides (Chlorothalonil, Nuarimol.Mancozeb, and Folpet) were a little toxic to adult females of the predator, showing$\leq$23.3% mortality, It may be suggested from these results that 4 insecticides, 4 acaricides, and 6 fungicides described could be incorporated into the integrated pest management system with A. womersleyi in apple orchard.

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Identification and Chemical Control of Gray Snow Molds Caused by Typhula spp. on Golf Course in Korea (우리나라의 골프코스에서 Typhula spp.에 의해 발생하는 설부병의 동정 및 방제)

  • Kim, Jeong-Ho;Shim, Gyu-Yul;Lee, Hye-Min;Moon, Hyo-Sun;Kim, Young-Ho
    • Asian Journal of Turfgrass Science
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    • v.21 no.2
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    • pp.147-154
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    • 2007
  • In March of 2004, gray snow mold (Typhula blight) caused by Typhula spp. occurred on perennial ryegrass (Lolium perenne L.) and Kentucky bluegrass (Poo pratensis L.) at MuJu golf courses in Jeonbuk Province. Leaves in the affected areas were matted together and frequently covered with white to grayish mycelia. Sclerotia were formed on the leaf blade, leaf sheath, or crown regions. The fungus isolated from the diseased leaf formed whitish mycelium, clamp connections, and light pink to brown, irregular-shaped small sclerotia of less than 1.4 mm in diameter, which are characteristic to Typhula incarnata. Optimum temperature ranges for mycelial growth were $5^{\circ}C$ to $15^{\circ}C$. The causal organism was confirmed to be T. incarnata as the partial sequence of its ribosomal RNA ITS1 (internal transcribed spacer) region was 91% homologous to those of T. incarnata in GenBank database. Out of the 14 fungicides tested fur antifungal activity in vitro, 10 fungicides including iprodione, tebuconazole, polyoxin D, flutolanil, hexaconazole, tolclofos-methyl, fosetyl-Al, mepronil, pencycuron+tebuconazole, and fenarimol completely inhibited fungal growth at their recommended concentrations. In the field test, these fungicides and others such as thifluzamide and thiram effectively controlled the gray snow mold of turfgrass with some variable degrees of control efficacies.

Survey of Fungicide Resistance for Chemical Control of Botrytis cinerea on Paprika

  • Yoon, Cheol-Soo;Ju, Eun-Hee;Yeoung, Young-Rog;Kim, Byung-Sup
    • The Plant Pathology Journal
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    • v.24 no.4
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    • pp.447-452
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    • 2008
  • Four hundred and sixty six isolates of B. cinerea were obtained from infected leaves, stems and fruits of paprika grown in greenhouses or plastic film houses in Gangwon province, Korea, between August and November in 2006 and 2007. These isolates were classified into five representative phenotypes of resistant (R) and sensitive (S) reactions as SSR, SRR, RSS, RRS and RSR according to the responses of isolates against benzimidazole, dicarboximide and N-phenyl-carbamate fungicide in order. The percentage of five phenotypes were 51.3, 2.4, 35.6, 8.1 and 2.6%, respectively. The SSR phenotype (51.3%) was the most common. Among the nineteen fungicide products evaluated to compare their efficacy against gray mold pathogen on the paprika fruit inoculated with fungal mycelia, the mixture of diethofencarb and carbendazim was the most effective followed by iprodione, boscalid, the mixture of iprodione and thiophanate-methyl, fludioxonil, polyoxin-B, fluazinam, the mixture of tebuconazole and tolyfluanid and procymidone; while in the assay methods inoculated with fungal spores, the mixture of tebuconazole and tolyfluanid was the most effective in controlling gray mold followed by boscalid, fludioxonil, the mixture of diethofencarb and carbendazim and the mixture of pyrimethanil and chlorothalonil.

Chemical and Biological Controls of Balloon Flower Stem Rots Caused by Rhizoctonia solani and Sclerotinia sclerotiorum

  • Lee, Young-Hee;Cho, Young-Son;Lee, Shin-Woo;Hong, Jeum-Kyu
    • The Plant Pathology Journal
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    • v.28 no.2
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    • pp.156-163
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    • 2012
  • Stem rots caused by Rhizoctonia solani and Sclerotinia sclerotiorum have been known as devastating diseases in balloon flower plants. Antifungal activities of four fungicides, azoxystrobin, polyoxin B, trifloxystrobin and validamycin A were evaluated in vitro, showing effective suppression with mycelial growth of the fungal isolates on PDA media. Efficacies of the four fungicides were also demonstrated in stem tissues of balloon flower plants against R. solani and S. sclerotiorum. A commercially available Bacillus subtilis strain Y1336 was tested in terms of antagonistic biological control of stem rot disease of balloon flower plants. The bacterial strain revealed its antifungal activities against R. solani and S. sclerotiorum demonstrated by dual culture tests using paper discs and two plant pathogenic fungi on PDA media, as well as by plant inoculation assay, indicating that this antagonistic bacterial strain can be incorporated into disease management program for balloon flower stem rot diseases together with the four chemical fungicides.