| Project/Area Number |
12640606
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生態
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| Research Institution | Tohoku University |
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Principal Investigator |
SAKAI Satoko Graduate School of Life Sciences, Associate Professor, 大学院・生命科学研究科, 助教授 (90272004)
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| Co-Investigator(Kenkyū-buntansha) |
HAKOYAMA Yuko Tohoku University, Graduate School of Life Sciences, Research Associate, 大学院・生命科学研究科, 助手 (80312544)
SAKAI Koki Tohoku University, Graduate School of Life Sciences, Associate Professor, 大学院・生命科学研究科, 助教授 (10272006)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2000: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | trade-off / size / number / 資源投資 / 資源 |
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| Research Abstract |
To explain the general tendency of large mothers to produce large offspring, we developed two models in which either the rate at which each single offspring extracts resources from the mother or the rate at which the mother supplies resources to all the offspring is limited (terminal- or upper-stream-limitation on resource transport, respectively). We also reanalyzed the data of Erythronium japonicum (Sakai 1998) to test the models. The terminal-stream-limitation model predicted that the optimal offspring size that maximizes the fitness of the mother increases with an increase in the maximum rate of resource extraction by each single offspring. Thus, large mothers produce large offspring if the maximum resource extraction rate is high in those mothers. The upper-stream-limitation model predicted that the optimal offspring size decreases with an increase in the maximum rate of resource supply by the mother to all the offspring. In E. japonicum, the maximum growth rate of a seed was independent of the number of seeds of a plant, suggesting that the resource extraction rate is limited at the individual seed level. The maximum growth rate was high in large plants and had a strong positive effect on final seed mass. Thus, the results were consistent with the terminal-stream-limitation model.
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