Quantitative limitation analysis of photosynthesis in greenhouse crops for the optimization of greenhouse environments

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20603
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0604:Agricultural economics and rural sociology, agricultural engineering, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Yokoyama Gaku 九州大学, 農学研究院, 助教 (80962472)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: 光合成 / 環境調節 / イチゴ / モデル / 定量的評価

Outline of Final Research Achievements

In this study, the potential limiting factors of photosynthesis—leaf boundary layer resistance, stomatal resistance, mesophyll resistance, and biochemical processes—were investigated in greenhouse strawberries under various environmental conditions using quantitative limitation analysis.The results revealed that under relatively mild environmental stress conditions, stomata are the main limiting factor for photosynthesis, but as environmental stress increases, limitations due to mesophyll resistance also increase. Additionally, this study was the first to evaluate the photosynthetic limitation caused by leaf boundary layer resistance, which has not been assessed in previous research. It was found that the leaf boundary layer can act as a limiting factor for photosynthesis in greenhouse crops, not only due to its resistance to carbon dioxide diffusion but also through its indirect effect on leaf temperature.

Free Research Field

農業気象学

Academic Significance and Societal Importance of the Research Achievements

温室作物生産においては，作物の生育および収量を決定づける生理生態反応である光合成を，環境調節によって効率よく通常レベルより高い状態に促進させることが試みられている．本研究の社会的意義は，温室作物の主要な光合成制限要因，すなわちボトルネックとなっているプロセスを定量的に示すことで，効率的な光合成の改善方法に資する情報を提供したことである．また，学術的意義としては，これまで光合成の制限要因の解析手法において考慮されてこなかった葉面境界層抵抗による制限の評価方法の構築と評価を初めておこなったことである．