2022 Fiscal Year Final Research Report

Model integrating photosynthetic pathways and estimation of leaf photosynthetic properties based on the model

Research Project

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Project/Area Number	20K15633
Research Category	Grant-in-Aid for Early-Career Scientists
Allocation Type	Multi-year Fund
Review Section	Basic Section 41040:Agricultural environmental engineering and agricultural information engineering-related
Research Institution	Central Research Institute of Electric Power Industry
Principal Investigator	Jishi Tomohiro 一般財団法人電力中央研究所, グリッドイノベーション研究本部, 主任研究員 (60816479)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	電子伝達系 / カルビン回路 / 補光 / CO2施用 / クロロフィル蛍光
Outline of Final Research Achievements	I have developed a model that assumes that the net photosynthetic rate of cucumber leaves is determined by the interaction between the electron transfer and the Calvin cycle. Then I have explained the effects of photosynthetic photon flux density (PPFD) and CO2 concentration on the net photosynthetic rate. The results showed that cucumber leaves grown at high CO2 concentrations tended to have a smaller maximum reaction rate of Calvin cycle compared to the maximum reaction rate of the electron transfer system. Furthermore, I proposed a method to calculate the parameters of the constructed model by measuring the changes in chlorophyll fluorescence intensity under fluctuating light with a certain period. This method was intended to estimate the effects of supplemental light and CO2 application in horticulture, but the accuracy of the estimation has not yet reached a practical level.
Free Research Field	生物環境工学
Academic Significance and Societal Importance of the Research Achievements	電子伝達系およびカルビン回路の最大反応速度を本モデルにより算出し、栽培環境がそれらに及ぼす影響を解析することにより、植物が限られたリソースでいかに光合成量を大きくして成長速度を高めるために適応してきたかの生態学的研究に貢献する可能性がある。また、農業分野において、環境を変化させた際の植物個葉または群落の純光合成速度をモデルにより推定しようとする場合に、光合成特性パラメータが植物の順化により変化するため、それらを固定して推定すると誤差が生じることを示した。