Assessment of the impact of spreading agriculture on aquatic plants by phytogeographical methods

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03093
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 41050:Environmental agriculture-related
• Research Institution: University of Human Environments
• Principal Investigator: Fuji Shinji 人間環境大学, 環境科学部, 准教授 (40228945)
• Co-Investigator(Kenkyū-buntansha): 牧 雅之 東北大学, 学術資源研究公開センター, 教授 (60263985) ; 那須 浩郎 岡山理科大学, 基盤教育センター, 准教授 (60390704)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 水生植物 / 農耕 / 人為的インパクト / 遺伝的変異 / 交雑

Outline of Final Research Achievements

Genetic analyzes of the chloroplast DNA and nuclear ITS regions of Najas spp. suggested the existence of introduced species, interspecific hybrids, and cryptic species. Genetic analyzes using the MIGseq method for the genus Vallisneria asiatica, Nymphoides peltata, and Cyperus spp. showed that there was a geographical genetic differentiation in V. asiatica and N. peltata. In Nymphoides peltata, we succeeded in clarifying the geographical structure and the existence of an artificial immigrant population, which had not been clarified by previous studies. In Cyperus spp., it was found that the genetic differentiation regarded as an infraspecific taxa are so great that they are identical to independent species. Based on these results, we are evaluating the effects of agriculture on the genetic structure of aquatic plants and proceeding taxonomic treatments.

Free Research Field

植物分類学

Academic Significance and Societal Importance of the Research Achievements

形態的特徴に乏しいイバラモ属植物の同定に遺伝子情報が有効であることが示され，種同定における遺伝子情報利用の有効性と信頼性が検証された．広域分布種の多い水生植物では地理的分化は小さいと考えられてきたが，日本列島のような狭い地域内での地理的分化が示されたことに加えてアサザでは人為的移動が示唆された．次世代シークエンサーを用いたMIGseq法による地理的分化の解析の有効性が示され，今後のさらなる活用が期待される．これらの成果は，水生植物の保全において地理的な分化に注意を払う必要性があること，さらに集団間分化の研究や保全事業の実施においては移入個体群の判別が必須であることを示している．