Significance of flower opening time as adaptation to diverse pollinator assembladge

2019 Fiscal Year Final Research Report

• Project/Area Number: 26440231
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: University of Tsukuba
• Principal Investigator: OHASHI Kazuharu 筑波大学, 生命環境系, 講師 (70400645)
• Project Period (FY): 2014-04-01 – 2020-03-31
• Keywords: 種間関係 / 進化生態 / 行動生態

Outline of Final Research Achievements

Flowers are often visited by animals with different pollination efficiencies. In interacting with such a wide variety of partners, it is of crucial importance for flowers to postpone visits by inefficient pollinators as much as possible, while prioritizing visits by more efficient pollinators, which allow them to make the best use of limited floral resources or gametes. Despite this interest, the timing of anthesis is not known for most species because most of their flowers last for more than 24 hours. Therefore, I quantified flower opening time for 150 angiosperm species in Japan using time-lapse photography. I have found that the flower-opening patterns can be classified into five types, which correspond to flower shape and flowering time: "Morning type", "Day type", "Night type", "Open/closure type" and "Bimodal type".

Free Research Field

植物進化生態学

Academic Significance and Societal Importance of the Research Achievements

送粉効率が異なるさまざまな動物が花を訪れるとき、花はどのような順序で彼らと接するのが望ましいか？ こうした「スケジュール最適化」の観点から植物の開花時刻の適応的意義を捉えた研究は、これまでほとんど例がなかった。本研究の広範な種間比較にもとづく、さまざまな植物種における開花時刻のパターンと他の花形質との関連の発見は、多様なパートナーに対する同時適応におけるジレンマ＝訪花者間トレードオフを最小限におさえるための花の戦略を明らかにした、先駆的な成果と言える。トレードオフを回避不能な制約としてではなく、解消可能な進化のターゲットと見なすことにより、従来の生物学にはなかった新たな視点を提供する。