| Project/Area Number |
07806023
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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 |
林学
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| Research Institution | Kyushu University |
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Principal Investigator |
KOBAYASHI Yoshichika Kyushu Univ., Dept.of Forestry, Asso.Prof., 農学部, 助教授 (90087594)
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| Co-Investigator(Kenkyū-buntansha) |
YAHATA Hisashi Kyushu Univ., Inst.of Tropical Agri., Prof., 熱帯農学研究センター, 教授 (90038290)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1996: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1995: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Chlorophyll fluorescence / Electron transport / Photorespiration / Photosynthesis / Quantum yield / Intact leaves |
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| Research Abstract |
The purpose of this research was to develop a method for estimating rates of electron transport in intact leaves by the simultaneous measurement of quantum yield and CO_2 uptake. Quantum yield of photosynthesis was determined from the fluorescence parameter (Fm'-Fs) /Fm', where (Fm'-Fs) was defined as the difference between steady state chlorophyll fluorescence (Fs) and maximum fluroescence (Fm') elicited by a saturating light pulse. The rate of electron transport through photosystem II (total electron flow) was calculated from the product of quantum yield and A (PFD), where A is the rate of absorbed photons as given by leaf absorptance, and PFD is the photon flux density at the leaf surface. The rate of electron transport dependent on CO_2 uptake (assimilative electron flow) was calculated from the gross photosynthetic rate in a leaf. The difference between the rates of total and assimilative electron transport was denoted as the rate of non-assimilative electron transport which depends on photorespiration and oxygen reduction. Available data provided quantitative information on the rate of non-assimilative electron flow in intact leaves. We also found that tree leaves with low rates of photosynthesis have greater activities of photorespiration than the other plant leaves with high rates of photosynthesis. The method for estimating the rate of electron transport in intact leaves provided useful information for the analyzes of photorespiration and photosynthesis limitation in tree leaves.
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