| Project/Area Number |
60480045
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物保護
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| Research Institution | Mie University |
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Principal Investigator |
ISHIZAKI Hiroshi Mie University , Professor, 農学部, 教授 (80024511)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAOKA Naoto Mie University , Research Associate, 農学部, 助手 (60174588)
KUNOH Hitoshi Mie University , Associate Professor, 農学部, 助教授 (20024573)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1986: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1985: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Keywords | Protoplast / Mode of action of fungicide / IBP / Fungicide-tolerant isolate of fungi / イネいもち病菌 |
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| Research Abstract |
The action mechanism of Kitajin P (IBP) to the rice blast fungus was examined mainly by cytological comparison of the fungal response at mycelium and protoplast levels. Low concentration (5-10 ppm) of IBP suppressed wall regeneration of protoplasts and reversion of hyphae from regenerated cells, while high concentration (50 ppm) affected cytoplasm membrane of protoplasts. Such a difference of the action mechanism of IBP at low and high concentration was not detected when the IBP effect was examined at mycelium level. Electron microscopy revealed that 4 ppm of IBP caused structural alteration and damage in protoplast cytoplasm within 2 hr after the onset of treatment, suggesting that such an effect is probably associated with the suppressive action of IBP on wall regeneration of protoplasts. Sensitivity of isolates to IBP is expressed parallely at both mycelium and protoplast levels. The sensitivity of isolates to IBP did not change in several generations of protoclone. These results were true when several IBP-tolerant isolates obtained in rice fields were tested. Tricyclazole and pyroquirone of no effect to suppress mycelium elongation of test fungus did not interfere with growth of protoplasts. Refferring our previous study, it was considered that the protoplast system would be suitable to test the effects of fungicides with suppressive action on hyphal elongation at mycelium level. Protoplasts responded to chemicals more sensitively than mycelia. Thus, it was concluded that the protoplast system would promote the study of effects of chemical on fungi. The advantages to utilize this system are summarized as follows, <i> ) the cytoplasmic responses to chemicals can be detected at relatively low concentrations of the chemicals within a short time, 24-48 hr, and <ii> ) the sensitivity of fungal isolates to fungicides can be readily tested.
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