Determining factors of flower coloration

ABSTRACT Diversity and distribution of flower coloration is a puzzling topic that has been extensively studied, with multiple hypotheses being proposed to account for the functions of coloration, such as pollinator attraction, protection against herbivory, and prevention of damage by ultraviolet light. Recent methodologies have allowed studies to consider the visual system of animals other than humans, helping to answer questions regarding the distribution of flower coloration. A survey of keywords in Web of Science shows floral color to be mainly studied in relation to macroevolutionary traits and biochemistry of pigments, focusing on pollination and anthocyanins, respectively. The present paper reviews mechanisms that determine the color of flowers. First, it is discussed how pigment, visual systems and signaling environments influence flower color; secondly, patterns of convergent evolution of flower color is debated, including evolutionary history, pollinator preference, flower color change, flowering season, and habitat. Third and last, patterns of flower coloration that have been found around the globe are addressed. In short, the aim is to contribute to ongoing research, by underlining mechanisms that lead to global patterns of coloration and indicating perspectives for future study on the topic.

摘要 花色彩的多样性与分布是一个备受学界关注却仍存诸多困惑的研究课题，学界已提出多种假说以阐释花色的生态功能，例如吸引传粉者、抵御植食性动物侵害，以及避免紫外线损伤。近年来的研究方法已允许研究者突破人类视觉系统的局限，从其他动物的视觉视角开展相关研究，这有助于解答花色分布领域的诸多悬而未决的问题。对Web of Science数据库的关键词检索结果显示，花色研究主要聚焦于两大方向：其一为与宏观演化性状相关的演化生物学研究，其二为色素生物化学相关的分子生物学研究，二者分别以传粉作用与花青素（anthocyanins）为核心研究主题。本文综述了决定花色的核心机制：首先探讨了色素、动物视觉系统以及信号传递环境如何共同塑造花色；其次围绕花色的趋同演化模式展开讨论，涵盖演化历史、传粉者偏好、花色动态变化、开花季节以及生境等关键影响因素；最后梳理了全球范围内已被观测到的花色分布格局。简言之，本文旨在通过阐明驱动全球花色分布格局的核心机制，并指明该领域未来的研究方向，为相关前沿研究提供有益参考。