Abrahamczyk Stefan, Dürr Ruben, Brenes Emanuel, Maglianesi María A
Botanical Garden, University of Osnabrück, Albrechtstraße 29, 49076, Osnabrück, Germany.
Botany Department, State Museum of Natural History Stuttgart, Rosenstein 1, 70191, Stuttgart, Germany.
Oecologia. 2025 Apr 30;207(5):74. doi: 10.1007/s00442-025-05718-z.
Research on pollination systems has largely focused on structures of mutualistic networks, whereas pollinator efficiency defining the quality of visits received much less attention. Different flower-visiting animals can vary in their pollination efficiency, e.g. due to their morphology, size or visitation frequency. Here, we analyse several reproductive traits, including flower morphology and reproductive system of Lobelia laxiflora and compare pollination efficiency of flower visitors based on seed set. We found experimentally that Lobelia laxiflora is completely self-incompatible and that the flowers are frequently visited by Colibri cyanotus, which did not show preferences for one flower sex. Diglossa plumbea was a more rare visitor and concentrated on female flowers Diglossa forced their bills deeply into the dorsally open corolla tube but did not pierce flowers. Corolla tube length perfectly fitted bill length of Colibri cyanotus and lots of pollen was deposited on its heads. In contrast, Diglossa plumbea visited flowers by sitting in different positions to them. Therefore, the reproductive flower organs got in contact with different parts of its body. Consequently, Colibri cyanotus was a very efficient pollinator probably due to the high level of trait matching, whereas Diglossa plumbea was not pollinating at all. In conclusion, our study documents a rare case of a temporally limited one-to-one dependency of a plant and a hummingbird species on the population level. Additionally, it highlights the significant role of morphological trait matching and bird´s behaviour in flower handling for efficient pollination and demonstrates that non-adapted flower visitors may fail as pollinators.
传粉系统的研究主要集中在互利网络的结构上，而定义访花质量的传粉者效率则很少受到关注。不同的访花动物传粉效率可能不同，例如由于它们的形态、大小或访花频率。在这里，我们分析了几种生殖性状，包括长花半边莲的花形态和生殖系统，并根据结实率比较了访花者的传粉效率。我们通过实验发现，长花半边莲完全自交不亲和，花朵经常被蓝喉蜂鸟拜访，蓝喉蜂鸟对花的性别没有偏好。铅色二舌蜂鸟是较罕见的访花者，集中拜访雌花。铅色二舌蜂鸟将喙深深插入背面开口的花冠筒中，但不会刺穿花朵。花冠筒长度与蓝喉蜂鸟的喙长完美匹配，大量花粉沉积在其头部。相比之下，铅色二舌蜂鸟以不同姿势坐在花上拜访花朵。因此，生殖花器官与它身体的不同部位接触。结果，蓝喉蜂鸟可能由于高度的性状匹配而成为非常有效的传粉者，而铅色二舌蜂鸟根本不进行传粉。总之，我们的研究记录了一个罕见的案例，即在种群水平上，一种植物和一种蜂鸟物种在时间上存在有限的一对一依赖关系。此外，它突出了形态性状匹配和鸟类在处理花朵时的行为对高效传粉的重要作用，并表明不适应的访花者可能无法成为传粉者。
