| Project/Area Number |
15380007
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Breeding science
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| Research Institution | Kagawa University |
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Principal Investigator |
ICHII Masahiko Kagawa University, President, 学長 (50036076)
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| Co-Investigator(Kenkyū-buntansha) |
TAKETA Shin Kagawa University, Faculty of Agriculture, Professor, 農学部, 教授 (40216891)
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| Project Period (FY) |
2003 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥10,200,000 (Direct Cost: ¥10,200,000)
Fiscal Year 2006: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2004: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2003: ¥4,200,000 (Direct Cost: ¥4,200,000)
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| Keywords | rice / silicon / gene / disease resistance / insect resistance / 根 / 養分 / 吸収 / 病害虫抵抗性 / 養分吸収 / ポジショナルクローニング / 飼料 / 突然変異体 / 消化性 |
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| Research Abstract |
A mutant with low Si uptake was induced by chemical mutagen treatment. We named the mutant GR1, because it was selected based on the resistance against germanium (Ge), an analogue of silicon (Si) with harmful effect on plants. Molecular mapping showed that the causal gene for low silicon uptake in GR1 was located on the long arm of rice chromosome 2.We determined Si content in the mutant and the wild type by chemical analysis and found that the mutant showed a range of 11-43% of Si content of the wild type in different plant organs studied. Interestingly, the mutant showed an increased level of lignin compared to the wild type; we ascribed this elevated lignin content to "compensation effect" which tends to retain firmness of the plant body. GR1 was more susceptible blast disease and insect attacks. There was no remarkable difference in plant mass productivity upon cultivation in a field, but digestibility of the whole-crop-silage by cows was similar between the mutant and wild type. Thus, the reduced level of Si in the mutant did not result in improvement in digestibility by cows. To know the root parts that contribute to Si uptake, we analyzed various rice root mutants defective in lateral roots or root hairs. Our analysis showed that Si was mainly absorbed through lateral roots and that root hairs did not show significant contribution to Si uptake in rice.
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