Reproductive interference in geographic cline of corolla tube length in Isodon umbrosus

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07559
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Tokyo Gakugei University
• Principal Investigator: Dohzono Ikumi 東京学芸大学, 教育学部, 准教授 (70462489)
• 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)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 地理的クライン / 繁殖干渉 / 形質置換

Outline of Final Research Achievements

We investigated whether reproductive interference between different species resulted in the geographic cline of corolla length of Isodon umbrosus. Isodon trichocarpus with very short corolla coexists with I. umbrosus with short corolla, and they shared a common bumblebee pollinator, Bombus honshuensis. In sympatric site, fertilization of I. umbrosus was reduced by pollen deposition from I. trichocarpus, suggesting reproductive interference between species. Precedence of conspecific pollen was detected in sympatric populations in I. trichocarpus, suggesting character displacement in pollen-pistil interactions. In addition, we found two genetic groups in I. umbrosus, suggesting that a historical process, the secondary contact between two diverged populations, caused geographic cline of corolla length.

Free Research Field

送粉進化生態学

Academic Significance and Societal Importance of the Research Achievements

生物形質に地理的なクラインがみられることはよく知られており，気候適応の例は多いが，種間相互作用が要因となっている例は極めて少ない。結果，種間相互作用と遺伝的に分化したグループの２次的接触によって地理的クラインがもたらされた。異種との共存メカニズムが明らかになり，生物多様性の理解に貢献するものである。