Pollinator-mediated mechanisms for increased reproductive success in early flowering plants

Mating activities change within a season in many animal and plant populations. In plants, selection towards early flowering is commonly observed. Pollinator-mediated selection is hypothesized to be a pervasive evolutionary force acting directionally on flowering time. However, pollinator-mediated mechanisms have rarely been tested in realistic field conditions, especially in perennial plants visited by a diversity of generalist insect pollinators. We examined pollinator visitation in eight Echinacea angustifolia populations in western Minnesota, USA, to gauge the potential for pollinator-mediated selection. Echinacea is a common prairie perennial that persists in isolated remnant populations. Echinacea is self-incompatible and is pollinated by a diversity of generalist solitary bees. A previous study found that early flowering Echinacea plants have higher seed set and their reproduction is less pollen-limited than late flowering plants. Twelve times throughout a flowering season, we qua...

多数动植物种群的繁殖活动会随生长季呈现动态变化。在植物类群中，针对开花时间提前的定向选择是普遍观测到的现象。传粉者介导的选择（pollinator-mediated selection）被假设为作用于开花时间的一类广泛存在的定向进化驱动力。然而，传粉者介导的相关机制极少在真实野外环境中得到验证，尤其是在受多种广谱性昆虫传粉者造访的多年生植物类群中。本研究针对美国明尼苏达州西部的8个窄叶松果菊（Echinacea angustifolia）种群开展传粉者访花调查，以评估传粉者介导选择的作用潜力。松果菊属（Echinacea）是北美草原常见的多年生类群，多存活于孤立的残存种群中。该属植物具有自交不亲和性，其传粉媒介为多种广谱性独居蜂类。既往研究显示，相较于晚开花个体，早开花的松果菊植株结籽率更高，且其繁殖过程受到的花粉限制程度更低。在整个开花季内，我们共计开展了12次[原文内容未完整呈现]。