Clarification of invasion routes and expansion mechanisms of alien Lolium specie

• Project/Area Number: 16K07230
• 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: Kyoto University
• Principal Investigator: Shimono Yoshiko 京都大学, 農学研究科, 准教授 (40469755)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2016: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 外来植物 / 侵入経路 / 輸入穀物混入種子 / 遺伝的分化 / 進化

Outline of Final Research Achievements

Lolium is a major agricultural weed in cereal crop fields, worldwide. Its seeds are introduced into Japan as contaminants in imported grain. They are also introduced intentionally as forage and revegetation materials. The microsatellite genetic heterogeneity indicated that individuals derived from the contaminants were locally established in sandy coasts but individuals derived from the commercial cultivars for fodder were distributed in agricultural fields. A reciprocal sowing experiment between a sandy coast and an agricultural field showed the home-site advantage in both populations derived from sandy coasts and agricultural fields. Differences of seed dormancy or flowering phenology between populations would affect the survival at each habitat in Japan. This study revealed that plants introduced through different pathways were genetically and ecologically different and expanded to different habitats.

Academic Significance and Societal Importance of the Research Achievements

(1) 外来生物がどのような侵入経路を経て国内に持ち込まれているのかを把握することは難しく、これまで侵入源と定着個体群間の直接比較はほとんど行われてこなかった。本研究では両者を直接比較することによって、異なる経路によって侵入した異系統が交雑することなく異なる生育地へ分布拡大していることを示した。
(2) 外来植物による被害を回避するためには、各植物に対する防除技術を開発するだけでなく、外部から持ち込まれる外来植物の侵入をいかに遮断するかも必要である。そのためには侵入経路の特定が重要である。本研究は、各生育地のドクムギ属の侵入経路を推定し、有効な外来植物の遮断策に貢献する基礎データを提供した。

Research Products

• [Journal Article] Reproductive biology and genetic population structure of two alien Lolium species inhabiting the sandy coasts of Japan (2019)
  • Author(s): Yumiko Higuchi, Yoshiko Shimono, Tohru Tominaga
  • Journal Title: Plant Species Biology Volume: 34 Issue: 2 Pages: 61-69
  • DOI: 10.1111/1442-1984.12235
  • Peer Reviewed
• [Presentation] ドクムギ属外来植物の分布パターンの違いをもたらす発芽特性の評価 (2019)
  • Author(s): 平田桃子・下野嘉子・清多佳子・冨永達
  • Organizer: 第66回日本生態学会大会
• [Presentation] ドクムギ属外来植物の分布パターンの違いをもたらす種特性の検討 (2018)
  • Author(s): 平田桃子・下野 嘉子・清多佳子・冨永 達
  • Organizer: 日本雑草学会第57回大会
• [Presentation] 輸入穀物に混入している雑草種子の組成と穀物輸入港における定着状況との関係 (2017)
  • Author(s): 西健志・下野嘉子・冨永達
  • Organizer: 日本雑草学会第56回大会
  • Place of Presentation: 宮崎県宮崎市
  • Year and Date: 2017-04-15
• [Presentation] 輸入穀物に混入している雑草種子の組成と穀物輸入港における定着状況との関係 (2017)
  • Author(s): 西健志・下野嘉子・冨永達
  • Organizer: 日本雑草学会第56回講演会
• [Presentation] The relationship between the composition of weed seed contaminants of imported grain and the vegetation of international trading ports (2017)
  • Author(s): Takeshi Nishi, Yoshiko Shimono, Tohru Tominaga
  • Organizer: 26 th Asian-Pacific Weed Science Society Conference
  • Int'l Joint Research