Studies on shifts of mycorrhizal fungi and symbiotic germination process in sect. Liparis (Orchidaceae)

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06815
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45030:Biodiversity and systematics-related
• Research Institution: National Museum of Nature and Science, Tokyo
• Principal Investigator: Tsutsumi Chie 独立行政法人国立科学博物館, 植物研究部, 研究主幹 (30455422)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 菌根菌 / 系統解析 / ラン科クモキリソウ属

Outline of Final Research Achievements

To clarify shifts of mycorrhizal partners and changes in symbiotic germination processes in Liparis sect. Liparis, molecular analyses on mycorrhizal fungi, symbiotic germination experiments, and anatomical studies on symbiotic embryos were conducted using Japanese Liparis species. The results of molecular analyses and symbiotic experiments suggested that the Liparis species had high specificity for its mycorrhizal partners and the plants in different lineages were associated with different Tulasnella strains. Therefore the plants likely diversified with changes in mycorrhizal partners. The anatomical study on symbiotic embryo development in L. suzumushi inferred that the symbiotic process proceeded through hyphal invasion, hyphal control in the basal part, and then appearance of meristematic cells in the apical part of the embryo. The symbiotic process stopped at a specific stage when the seeds of L. suzumushi were cultivated with incompatible fungi.

Free Research Field

多様性生物学

Academic Significance and Societal Importance of the Research Achievements

ランと菌根菌に関する研究例は多々あるが、系統関係を考慮し共生培養実験により定量的に菌に対する特異性を調べた研究例は少ない。本研究では、植物と菌、両者の系統関係を考慮し、共生培養実験を重ねて、植物の進化と菌根菌の変化を推定した。さらにスズムシソウの共生胚の細胞内動態の調査から、種子発芽時における菌根共生の成立には、菌糸の侵入、胚の基部側細胞での菌糸の制御、その後の活発な胚細胞分裂が関与していること、スズムシソウでは非適合な菌とでは特定の段階で停止することが明らかとなった。今後スズムシソウは、菌根共生の成立過程における遺伝的なメカニズムの解明など、さまざまな研究への発展が期待できる。