Exhaustive survey of understory herbaceous plants obtaining organic carbon through arbuscula mycorrhizal networks.

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K19356
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 45:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: Yamagata University
• Principal Investigator: Yokoyama Jun 山形大学, 理学部, 教授 (80272011)
• Co-Investigator(Kenkyū-buntansha): 富松 裕 山形大学, 理学部, 教授 (40555398)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Keywords: 安定同位体 / 栄養摂取様式 / 菌根菌ネットワーク / 菌従属栄養植物 / 森林群集

Outline of Final Research Achievements

Many green orchids and pyroloids have been found to be partially mycoheterotrophic (i.e. mixotrophic) feeding on ectomycorrhizal fungi associated with surrounding trees. Whereas many fully mycoheterotrophic plants feed on arbuscular mycorrhizal (AM) fungi, the prevalence of mixotrophy in AM plants is still debated. We investigated 13C and 15N isotopic abundances of understory plants, canopy trees, and AM fungi in a Japanese temperate forest to explore potential mixotrophic understory plant species. Our results suggest that isotopic abundances are of limited help in finding potential mixotrophs that feed on AM fungi, even though mixotrophic species, if any, are likely to be enriched in 13C.

Free Research Field

多様性生物学

Academic Significance and Societal Importance of the Research Achievements

ラン科とツツジ科では、外生菌根菌に依存する部分的菌従属栄養植物が多く見出されており、炭素の安定同位体比が主要な根拠となってきた。一方、大多数の植物種がアーバスキュラー菌根菌（AM菌）と共生しているにも関わらず、AM菌に依存する部分的菌従属栄養植物は積極的に探索されてこなかった。本研究では、部分的菌従属栄養植物の新たな特定には至らなかったが、安定同位体比の有効性と限界について、詳細な検討を行うことができた。