Phylogeography of evergreen Fagaceae trees in the warm temperate zone in Japan using genomic approach

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K06381
• 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: Osaka University
• Principal Investigator: Aoki Kyoko 大阪大学, 大学院連合小児発達学研究科, 寄附講座助教 (70378537)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 照葉樹林 / レフュジア / 遺伝的多様性 / 次世代シーケンス

Outline of Final Research Achievements

We investigated the demographic history of the broadleaved evergreen trees Castanopsis and Quercus (Fagaceae) during the last glacial period in Japan using EST- associated microsatellites or restriction site associated DNA sequence. In C. sieboldii, we used approximate Bayesian computation for model comparison and parameter estimation for the demographic modeling. The results strongly support a demographic scenario that the Ryukyu Islands and the western parts in the main islands were derived from separate refugia and the eastern parts in the main islands and the Japan Sea groups were diverged from the western parts prior to the coldest stage of the Last Glacial Maximum (LGM). Our data indicate that multiple refugia survived at least one in the Ryukyu Islands, and the other three regions of the western and eastern parts and around the Japan Sea of the main islands of Japan during the LGM.

Free Research Field

分子植物地理学

Academic Significance and Societal Importance of the Research Achievements

日本列島に分布する照葉樹林を構成する植物種について，種内多型量が多く得られる解析方法を用いて集団動態の解析を行うことによって照葉樹林構成種の氷期のレフュジアの位置や規模，その後の変遷過程を推定できた。照葉樹林を構成する複数種の地理的変異パターンを明らかすることで森林生態系の変遷過程を考察することができ，生物地理学的研究の発展へ貢献できる。また，多数の生物種群について地域ごとの遺伝的多様性のあり方が明らかになることで遺伝的多様性の保全や野生生物の移植に対して指針を与えられる。