Morphological specialisation of heterantherous Rhynchanthera grandiflora (Melastomataceae) accommodates pollinator diversity.
Morphological specialisation of heterantherous Rhynchanthera grandiflora (Melastomataceae) accommodates pollinator diversity.
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DOI：
10.1111/plb.13102
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发表时间：
2020-02
期刊：
影响因子：
3.9
通讯作者：
Sabine Konzmann;F. Hilgendorf;Carolin Niester;A. Rech;K. Lunau
中科院分区：
文献类型：
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作者：
Sabine Konzmann;F. Hilgendorf;Carolin Niester;A. Rech;K. Lunau
热带Mexicataceae植物家族的特征是由孔裂花药组成的花过滤器选择蜂授粉的蜜蜂。雄蕊通常是二形的，有时具有明显的取食和授粉功能。Rhynchanthera grandiflora产生无花蜜的花，具有四个短雄蕊和一个长雄蕊;所有花药都具有一个向上的孔的狭窄伸长。我们测试了不同的觅食蜜蜂和花粉从两种花药类型的生活力的花粉转移。研究了花药形态对花粉释放方向和散射角的影响，以确定植物的繁殖策略。中型到大型蜜蜂在特定位置对花朵进行超声波处理，即使在这些合法的访客中，花粉转移的概率也与蜜蜂的大小相关。小蜜蜂充当花粉小偷或强盗。花药喙和孔的形态有助于引导和集中花粉射流向传粉者的身体释放花超声波。由于短雄蕊和长雄蕊分别位于腹侧和背侧，传粉者的身体被广泛的花粉覆盖。这提高了植物异交的机会，而不管蜜蜂身体的哪一部分接触柱头。因此，R. grandiflora还能够使用各种大小的蜜蜂物种作为花粉载体。将花粉散布在传粉者全身的策略是相当昂贵的，但通过确保大部分释放的花粉实际上转移到蜜蜂身上来平衡。因此，花的R。grandiflora说明了如何专门的形态可能有助于提高传粉功能组的传粉。
The tropical Melastomataceae plant family is characterised by poricidal anthers which constitute a floral filter selecting for buzz-pollinating bees. Stamens are often dimorphic, sometimes with discernible feeding and pollinating functions. Rhynchanthera grandiflora produces nectarless flowers with four short stamens and one long stamen; all anthers feature a narrow elongation with an upwards facing pore. We tested pollen transfer by diverse foraging bees and viability of pollen from both anther types. The impact of anther morphology on pollen release direction and scattering angle was studied to determine the plant's reproductive strategy. Medium-sized to large bees sonicated flowers in a specific position, and the probability of pollen transfer correlated with bee size even among these legitimate visitors. Small bees acted as pollen thieves or robbers. Anther rostrum and pore morphology serve to direct and focus the pollen jet released by floral sonication towards the pollinator's body. Resulting from the ventral and dorsal positioning of the short and long stamens respectively, the pollinator's body was widely covered with pollen. This improves the plant's chances of outcrossing irrespective of which bee body part contacts the stigma. Consequently, R. grandiflora is also able to employ bee species of various sizes as pollen vectors. The strategy of spreading pollen all over the pollinator's body is rather cost-intensive, but counterbalanced by ensuring that most of the released pollen is in fact transferred to the bee. Thus, flowers of R. grandiflora illustrate how specialised morphology may serve to improve pollination by a functional group of pollinators.