Development of methodology using environmental DNA to monitor insect pathogens of forest defoliating insects

2022 Fiscal Year Final Research Report

• Project/Area Number: 17H03826
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Forest science
• Research Institution: The University of Tokyo
• Principal Investigator: Kamata Naoto 東京大学, 大学院農学生命科学研究科(農学部), 教授 (90303255)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 昆虫病原性糸状菌 / 土壌DNA / 環境DNA / アンプリコン解析 / 次世代シーケンス / 菌類

Outline of Final Research Achievements

Spatial variation in fungal communities in forest soils is high. Entomopathogenic fungi include important natural enemies of forest insects, but their information is limited except during outbreaks, partly because many of them live in soil. The objective of this study was to develop a method for monitoring entomopathogenic fungi in soil using environmental DNA methods. Three different methods were used to extract DNA from 0.4 g (according to a kit recipe) and 15 g (intention to collect fungal DNA more widely) of soil volume. Amplicon analysis was performed using next-generation sequencers. Contrary to expectations, the smaller the amount of soil used for extraction, the greater number of fungal OTU were detected. The results of this study indicate that the best strategy is to sample a large number of small soil samples.

Free Research Field

森林昆虫生態学

Academic Significance and Societal Importance of the Research Achievements

目にみえない土壌中に生息する菌類のモニタリング手法として環境DNAを用いた次世代シーケンスによるアンプリコン解析の手法開発を検討した。抽出に用いる土壌量を増やすことにより菌類DNAをより網羅的に捕捉することを目指したが、予想とは逆に、少ない土壌量の方がより網羅的な抽出が可能であった。これは土壌量を増やすと腐植酸などの影響により抽出が阻害されることが原因の一つと考えられた。実際にこれまでも、同様の視点から大量の土壌を使ったDNA抽出技術の開発が行われてきたが、本研究の結果は、これらの研究に一石を投じるものである。