Proposal of guidelines to prevent genetic deterioration due to ex situ conservation-for an extinct species in the wild, Eriocaulon heleocharioides

• Project/Area Number: 17K07275
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Conservation of biological resources
• Research Institution: National Museum of Nature and Science, Tokyo
• Principal Investigator: Tanaka Norio 独立行政法人国立科学博物館, 植物研究部, 研究主幹 (10311143)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 生息域外保全 / 野生絶滅種 / 野生復帰 / 遺伝的劣化 / コシガヤホシクサ / 近交弱勢 / 水生植物 / 遺伝的多様性

Outline of Final Research Achievements

Eriocaulon has been shown to undergo inbreeding depression during reproductive process under ex situ conservation. Given the genetic diversity and behavior of maternal mating, it was considered that it did not occur decisively at the time of rescue from the last habitat and could be influenced by ex situ conservation methods. In particular, it can be improved by selecting a cultivation condition, such as cultivation in underwater environment, improvement of pollination environment, and use of individuals with weak inbreeding depression.

Academic Significance and Societal Importance of the Research Achievements

野生絶滅種においては生息域外保全個体群が全てであるため、その保全管理と将来的な野生復帰の指針は極めて重要である。本成果は、その重要性が学術的に再確認されるとともに、今後の改善の指針を示す重要な知見となる。この知見および研究ノウハウはコシガヤホシクサの実際の保全を促進することはもちろん、他の野生絶滅種および絶滅危惧種の域外保全管理および指針研究の先行事例として有用な意味を持つ。

Research Products

• [Journal Article] Floral and pollination characteristics of Eriocaulon heleocharioides, an extinct species in the wild, for evidence‐based conservation management (2021)
  • Author(s): Horiuchi, Yuju, Takashi Kamijo, and Norio Tanaka
  • Journal Title: Plant Biology Volume: - Issue: 4 Pages: 546-555
  • DOI: 10.1111/plb.13236
  • Peer Reviewed
• [Journal Article] Effect of herbivore predation and water-wave disturbance on the survival of wild extinct aquatic plant Eriocaulon heleocharioides (Eriocaulaceae) in the reintroduction site (2021)
  • Author(s): Tanaka, N., Tsuda, K., Horiuchi, Y., Nagata, S., Kamijo, T. and Nishihiro
  • Journal Title: Bulletin of the National Museum of Nature and Science, Series B Volume: 46(4) Pages: 1-7
  • NAID: 40022445474
  • Peer Reviewed
• [Journal Article] Biological and ecological constraints to the reintroduction of Eriocaulon heleocharioides (Eriocaulaceae): A species extinct in the wild (2020)
  • Author(s): Horiuchi, Yuju, Takashi Kamijo, and Norio Tanaka
  • Journal Title: Journal for Nature Conservation Volume: 56 Pages: 1-8
  • DOI: 10.1016/j.jnc.2020.125866
  • Peer Reviewed
• [Journal Article] Effects of net sheltering, water depth, and soil management on the survival and reproduction of the wild extinct aquatic plant Eriocaulon heleocharioides in Sanuma Lake, Japan. (2020)
  • Author(s): Tanaka, N., Horiuchi, Y., Nagata, S., Hasegawa, S. and Kamijo, T
  • Journal Title: Bulletin of the National Museum of Nature and Science, Series B Volume: 45 Pages: 1-10
  • NAID: 40022195815
  • Peer Reviewed
• [Journal Article] First molecular phylogenetic insights into the evolution of Eriocaulon (Eriocaulaceae, Poales) (2019)
  • Author(s): Larridon, I., Tanaka, N., Liang, Y., Phillips, S. M., Barfod, A. S., Cho, S-H., Gale. S. W., Jobson, R. W., Kim, YD., Li, J., Muasya, A. M., Parnell, J. A. N., Prajaksood, A., Shutoh, S., Souladeth, P., Tagane, S., Tanaka, Nob., Yano, O., Mesterhazy, A., Newman, M. F. and Ito, Y.
  • Journal Title: Journal of Plant Research Volume: 132 Issue: 5 Pages: 589-600
  • DOI: 10.1007/s10265-019-01129-3
  • NAID: 40022011587
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Effect of net sheltering on the survival of a wild extinct aquatic species, Eriocaulon heleocharioides in its reintroduction site. (2018)
  • Author(s): Norio Tanaka, Yuju Horiuchi, Yujian Duang, Seri Hasegawa, Shoh Nagata and Takashi Kamijo
  • Journal Title: Bull. Natl. Mus. Nat. Sci., Ser. B Volume: 44 Pages: 1-7
  • Peer Reviewed
• [Presentation] 野生絶滅種コシガヤホシクサの野生復帰を目指した保全研究-成果、現状、課題 (2021)
  • Author(s): 田中法生、堀内勇寿、永田翔、上條隆志
  • Organizer: 日本生態学会第68回大会.
• [Presentation] 生きた標本資料の価値を究める-野生絶滅種コシガヤホシクサの保全と野生復帰 (2020)
  • Author(s): 田中法生
  • Organizer: 日本生態学会関東地区会公開シンポジウム「生物標本情報の活用による保全遺伝学の新展開」
  • Invited
• [Presentation] 野生絶滅種コシガヤホシクサの再導入地における生存に捕食生物と波浪が及ぼす影響 (2020)
  • Author(s): 津田京伽・堀内勇寿・永田翔・西廣淳・田中法生
  • Organizer: 日本生態学会第67回全国大会
• [Presentation] 花粉DNA Barcodingによる植物園の送粉環境評価:ポリネーターガーデンと域外保全の模索 (2020)
  • Author(s): 堀内勇寿・永田翔・上條隆志・田中法生
  • Organizer: 日本生態学会第67回全国大会
• [Presentation] 野生絶滅種コシガヤホシクサにおける交配方法に由来する形質変化と母性効果の検出 (2019)
  • Author(s): 堀内勇寿・永田翔・上條隆志・田中法生
  • Organizer: 日本生態学会第66回全国大会
• [Presentation] 越谷生まれの“地球の宝物”を守る-コシガヤホシクサ野生復帰プロジェクトー (2018)
  • Author(s): 田中法生
  • Organizer: 発見80周年記念シンポジウム-越谷で発見された地球の宝物「コシガヤホシクサ」〜.
  • Invited
• [Presentation] 消えゆく水草を守る-水草の不思議とその危機、そして私たちにできること〜 (2018)
  • Author(s): 田中法生
  • Organizer: 葛西臨海水族園水草講演会
• [Presentation] 野生絶滅種コシガヤホシクサの生存と成長に交配方法と栽培環境が与える影響 (2018)
  • Author(s): 長谷川 セリ・堀内 勇寿・段 雨佳・永田 翔・上條 隆志・田中 法生
  • Organizer: 第65回日本生態学会大会
• [Presentation] The road ahead for the ex situ conservation of aquatic plants: a project to restore the extinct species Eriocaulon heleocharioides to the wild (2017)
  • Author(s): 田中法生
  • Organizer: XIX International Botanical Congress
  • Int'l Joint Research
• [Book] 絶滅危惧種の生態工学―生きものを絶滅から救う保全技術― (2019)
  • Author(s): 田中法生（分担執筆）
  • Total Pages: 230
  • Publisher: 地人書館
  • ISBN: 9784805209301
• [Book] 水草の疑問50 (2018)
  • Author(s): 田中法生
  • Total Pages: 245
  • Publisher: 成山堂
  • ISBN: 9784425983315
• [Remarks] 研究者紹介
  • URL: http://www.kahaku.go.jp/research/researcher/researcher.php?d=ntanaka