Searching for optimum nodulation level for maximizing yield based on carbon-nitrogen balance of soybean

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K14842
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Crop production science
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Matsunami Toshinori 国立研究開発法人農業・食品産業技術総合研究機構, 東北農業研究センター, 主任研究員 (10506934)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ダイズ / 生物共生機能 / 根粒着生 / 乾物生産 / 収量

Outline of Final Research Achievements

We analyzed the interactive effects of temperature and [CO2] on nodulation level and searched for optimum nodulation level for maximizing yield in soybean. Plants were subjected to two levels of [CO2] (ambient or elevated: ambient + 200 μmol mol－1) and two temperature regimes (normally or high: normally + ca. 4 or 5 °C) using temperature gradient chambers. Nodule size was enhanced by CO2 enrichment, whereas root biomass and number of nodule were increased by high temperature. Nodulation level was the greatest in the elevated [CO2] × high temperature regime. There was a significant correlation between nodulation level and seed size, but not correlation to seed yield. These results indicated that promoting of nodulation level through increasing in size of nodulation induced by carbon supply connects to increasing in seed size, contributes to high yield production in soybean. The optimum nodulation level for maximizing yield was obscured, thus our challenge was not fully verified.

Free Research Field

作物学

Academic Significance and Societal Importance of the Research Achievements

本研究においてノジュレイションと収量性の関係が明らかになったことから、本研究の試験環境を再現した遺伝子応答等の試験を行うことで、ダイズと根粒菌による生物共生機能の遺伝子レベルから物質生産レベルまでの共生機能の関わり方が明らかになる。そして、共生機能の多収への関わり方が明らかになれば、最適ノジュレイションレベルを発揮するダイズの生育特性や栄養状態を示すような数値パラメーターを指標にした栽培管理技術による生物共生機能の制御という新たな農業技術を提案できる。このように、本研究成果は生物共生機能の農学・生物学的な意義の解明だけでなく、ダイズの生産性向上という点においても意義深いと考えられる。