Carbon allocation to mycorrhizal fungi symbiotic to very fine roots

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06128
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Tokyo University of Agriculture
• Principal Investigator: IMAI Nobuo 東京農業大学, 地域環境科学部, 准教授 (00722638)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 菌根菌 / 森林 / 炭素動態 / 呼吸 / 土壌微生物

Outline of Final Research Achievements

Carbon allocation to mycorrhizal fungi has been lumped together with root respiration, and therefore it has been largely ignored. Previous studies on mycorrhizal respiration were conducted using the chamber method on the forest floor. Mycorrhizal respiration rate using the chamber method can obtain a low, and a mixed value from multiple trees. Given that mycorrhizal respiration may vary with host tree species, mycorrhizal fungal species, root size, and prior photosynthesis rate, development of a measuring method at a fine root scale is needed. Here, we developed a method to measure the respiration rate of mycorrhizas symbiotic to very fine root, using a syringe-type microchamber in combination with a fungicide. We found that mycorrhizal respiration rates varied depending on the life type (i.e., evergreen or deciduous) of the host tree.

Free Research Field

植物生態学

Academic Significance and Societal Importance of the Research Achievements

樹木は光合成で得た炭素のうちの相当量を、根とそれに共生する菌根菌に呼吸基質として配分している。こうした根圏呼吸の理解は、温暖化応答予測や物質循環の解明に欠かせない。本研究は、これまで植物根の呼吸と一括りにされほとんど無視されてきた菌根菌呼吸速度の測定手法を開発した。また本手法は、従来の林分レベルでの測定では不可能だった、各樹種の高活性根圏における菌根菌呼吸を測定するもので、菌根菌への炭素配分パターンの詳細な理解に寄与できる。