Feasibility study of avoidance of high temperature stress in rice by mutation-enhanced leaf transpiration cooling

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K07278
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Crop production science
• Research Institution: National Agriculture and Food Research Organization (2016-2018); National Institute for Agro-Environmental Sciences (2015)
• Principal Investigator: Fukuoka Minehiko 国立研究開発法人農業・食品産業技術総合研究機構, 農業環境変動研究センター, 上級研究員 (40435590)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 水稲 / 高温不稔 / 群落微気象

Outline of Final Research Achievements

To evaluate the availability of cooling by enhanced transpiration from leaf surface as an avoiding mechanism for heat induced spikelet sterility in rice, a high leaf transpiration mutant line (LTL) of cultivar ‘Hinohikari’ was compared with its wild type (WT) for sterility under the field condition at the test sites in Japan where an encounter with heat wave during their flowering stage could be expected. In the year that heat waves hit the flowering stage of LTL and WT, rough rice yield of WT decreased to 34% of that in the years of less severe temperature, whereas that of LTL showed 10 percentage point less decrease, indicating that the cooling by enhanced transpiration from leaf surface can be a promising option to avoid heat induced spikelet sterility in rice.

Free Research Field

農業気象学

Academic Significance and Societal Importance of the Research Achievements

イネが開花期に高温にさらされることにより稔らなくなる現象である高温不稔は、もし発生するとその後の生育条件がどんなに良くても、もはや籾の中で子実が充実することはなく空籾となり、収量の深刻な減少をもたらす。地球温暖化の進行によりイネの高温不稔は今後の発生の増大が懸念されることから、葉蒸散の強化による群落の冷涼化が回避技術のひとつとして利用できる可能性が本課題の実施を通じて示されたことは、日本を始めとする世界の米食地域の食料供給の安定化に寄与しうる進展である。