| Project/Area Number |
06640810
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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 | Faculty of Science, Chiba University |
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Principal Investigator |
TSUCHIYA Takayoshi Dept.Biol., Fac., Sci., Chiba Univ., Assistant, 理学部, 助手 (20227432)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Humidity-induced diffusion / Thermal transpiration / Ventilation / Photosynthesis / Plant ecophysiology / Aquatic ecology / 蒸散 / 植物生態学 / 水界生態学 |
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| Research Abstract |
Convective gas throughflow in aquatic higher plants has been considered to sustain high root activities by aerating roots and the surrounding soils. The convective gas throughflow should affect the other functions besides the roots. This study was conducted to clarify whether the gas flow through a leaf should also increase net photosynthesis of the leaf itself.
In many floating-leaved plants, e.g., Nymphea odorata, N.alba and Nuphar lutea, net photosynthetic rate of floating leaves was slightly higher with gas throughflow than without gas throughflow. In the measurement with a leaf chamber in which the air was artificially pressurized, net photosynthetic rate was positively correlated with gas flow rate through a leaf petiole. The CO_2 concentration of the convective gas increased with decreasing its flow rate. This often exceeded 1 mPa Pa^<-1> even at high gas throughflow rates. The correction factor of the estimate of net photosynthetic rate, because the petiole plays a role of an additional outlet of leaf assimilation chamber, was negligible. Nevertheless, this suggests that intercellular CO_2 concentrations of aerenchyma would be different from those of palisade parenchyma. Further studies on CO_2 concentration distribution within a leaf are necessary.
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