2018 Fiscal Year Final Research Report

Estimate of Quaternary paleoenvironment from molecular information of microfossils

Research Project

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Project/Area Number	15H02960
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Geography
Research Institution	Nara Women's University
Principal Investigator	TAKADA Masashi 奈良女子大学, 人文科学系, 教授 (60273827)
Co-Investigator(Kenkyū-buntansha)	浅田晴久奈良女子大学, 人文科学系, 准教授 (20713051) 佐伯和彦奈良女子大学, 自然科学系, 教授 (40201511) 前迫ゆり大阪産業大学, デザイン工学部, 教授 (90208546)
Research Collaborator	Shimada Aiko
Project Period (FY)	2015-04-01 – 2019-03-31
Keywords	植物珪酸体 / 微化石 / 同位体比 / 古環境 / 火山灰土 / 有機物 / 花粉化石 / DNA
Outline of Final Research Achievements	We examined possibilities that new methods could be introduced into Quaternary paleoenvironment reconstruction using DNA analysis of pollen fossils and oxygen isotope ratio of phytolith fossils. We examined PCR amplification conditions for chloroplast genome analysis using modern conifers as test samples. Although we could obtain primers suitable for analysis of phylogenetic comparison evolution above the genus level, we could not find the amplification condition suitable for species identification from total DNA samples. Further examination of amplification conditions is necessary for the DNA analysis of pollen fossils, which are anticipated to decrease and fragment the DNA content itself due to aging. Since differences in oxygen isotope ratio analysis results by different methods were recognized for phytoliths extracted from modern plants, it is necessary to establish a routine way to measure the oxygen isotope ratio of phytoliths with standard samples.
Free Research Field	自然地理学
Academic Significance and Societal Importance of the Research Achievements	古植生や生態学的な植生-環境相互関係の地史的変遷に関して、陸域に分布する連続堆積物である火山灰土に含まれ残存性にすぐれた植物珪酸体の分子科学的情報に着目した解析と、陸域有機物のDNA情報から新しい解析手法が導入できれば、当該関連研究分野に新たな情報をもたらすことが期待できる。これらは日本はもちろん世界的にみてもまだ十分手のつけられていない研究分野であり、今後の研究の進展が与える波及効果は決して小さくない。本研究によって本格的な対象サンプルの解析に向けて必要となる具体的な検討事項が明らかにされたので、今後は、本研究の成果を踏まえた解析手法の確立に向けた取り組みを進める予定である。