High temperature resistance of the grain-filling depending on low grain growth rate and high assimilation in rice

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H04444
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Crop production science
• Research Institution: Shimane University
• Principal Investigator: Kobata Tohru 島根大学, 生物資源科学部, 名誉教授 (60186723)
• Co-Investigator(Kenkyū-buntansha): 氏家 和広 島根大学, 学術研究院農生命科学系, 准教授 (60465276) ; 三ツ井 敏明 新潟大学, 自然科学系, 教授 (70183960)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: イネ / 高温 / 登熟 / 品質 / 子実増加速度 / 同化 / 品種間差 / イネコアコレクション

Outline of Final Research Achievements

High temperature resistance in rice grain yield and quality is expected. Cultivars of a less increase in the grain filling under high temperature conditions was selected from rice of the world and Japan rice core collection. The less increase in the grain filling rate was expected to result a high temperature resistance of the grain filling because of relief in a lack of assimilate supply to the grain and keeping starch accumulation in grains. When panicles from these collection cultivars were solution cultured under 30 C, grain filling rate indicated diverse variability. The variability for selected typical cultivars was evidenced under diverse temperature and pot cultivated conditions. Metabolic processes for starch synthesis would relate with the cultivar difference in a response of the grain filling to high temperatures.

Free Research Field

作物学

Academic Significance and Societal Importance of the Research Achievements

今後も日本のような中緯度地域の稲作地域において温暖化による高温化が進行すると予測される．このような条件下で今後も安定した食料生産を行うためには栽培的対応とともに品種的改良が不可欠である．本研究結果は高温に最も影響されやすい子実成長を維持するための特性としての子実の温度反応性に着目し，品種的多様性とその利用可能性について明らかにすることができた．今後、圃場におけるこれらの性質の再現性の確認，もう一つの体制となりうる同化の維持の特性についてさらに解明することで高温耐性品種の開発につながる可能性がある．