Rice allelopathy for the development of the sustainable agriculture

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05598
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Kagawa University
• Principal Investigator: Kato Hisashi 香川大学, 農学部, 教授 (50222196)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: アレロパシー / イネ / 環境配慮型農業 / イヌビエ / 雑草防除

Outline of Final Research Achievements

Allelopathic activity of rice plants showed 5.3- to 6.3-fold increases when rice and barnyard grass were grown together. Root exudates of barnyard grass increased allelopathic activity and momilactone B concentration in rice plants. The root exudates of barnyard grass were then purified by several choromatographic runs with monitoring the momilactone-induced activity. Two active substances were isolated and characterized as lolioide and monocerin. Both substances induced the allelopathic activity of rice plants and the momilactone concentration in rice plants as well as momilactone secretion level from rice into paddy fields. These results suggest that lolioide and monocerin may be involved in the barnyard grass-induced allelopathic activity of rice seedlings.

Free Research Field

Chemical ecology

Academic Significance and Societal Importance of the Research Achievements

本研究では，イヌビエの根分泌物からイネのアレロパシー活性を増加させる主成分を２種類単離同定した．また，それらの物質をイネに与えると，イネのアレロパシー活性が増加することが明らかになった．今後，これらの物質をイネ栽培に応用することで，イネにおけるモミラクトンの生産とイネから圃場へのモミラクトンの分泌を促進することができる．モミラクトンは，病原菌抵抗性や雑草の成長を抑制することができるので，イネ栽培において除草剤や防菌剤などの農薬の使用を減らすことが可能になる．そのため，農薬の使用を抑制することができ，環境配慮型のイネ栽培方法が開発できる.