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Fine-tuned floral filters in melittophilous flowers sort out particular bees

嗜蜂花中经过微调的花卉过滤器可以筛选出特定的蜜蜂

基本信息

批准号：
315642637
负责人：
Professor Dr. Klaus Lunau
金额：
--
依托单位：
Institut für Sinnesökologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/315642637?language=en
关键词：
Fine tuned floral filters melittophilous

项目摘要

Bees are considered reliable pollinators; this is corroborated by the bees frequency of flower visits and their flower constancy, but challenged by the bees collection of pollen for larval food provisioning. Pollen grains which have been groomed into the pollen transport structures are no longer available for pollination. This allocation of pollen for a purpose other than pollination amounts to a dilemma for bee-pollinated flowering plants. In this project we will investigate three so far unstudied and coherent aspects of this pollen dilemma by testing whether and how flowers manipulate bees for optimization of pollen transfer. 1. Spines of pollen grains are involved in the mechanical defence of pollen grains from being collected by corbiculate bees. We will test the role of spine number, spine length, pollen grain diameter, pollen hydration and added regurgitated nectar in order to understand the mechanism by which spiny pollen is defended against collection by corbiculate bees. In addition we will test if flowering plants use spiny pollen grains to restrict bees to nectar collection, because nectar collecting bees groom themselves less frequently. 2. Pollen grains on safe sites of bees bodies experience a smaller probability of being groomed into the pollen transport structures, from where they cannot pollinate flowers. We will test whether keel blossoms represent an exception and can use the scopa as a kind of safe site of pollinating bees. We will test whether the stiffness of keel flowers, which can only be opened by megachilid bees, represents a floral adaptation to promote transfer of pollen grains from the ventral scopa of the bee to stigma of the flower. This would be the first evidence for pollination by fertile scopal pollen and constitute strong selective pressure for the respective flowers to exclude bees that do not possess a ventral scopa. 3. Many bee-pollinated flowers possess pollen- and stamen-mimicking structures which are considered to function as visual floral guides. We will study the as yet unexplored function of pollen- and stamen-mimicking structures to trigger grooming behaviour in bees by means of tactile stimuli. We will test the hypothesis that stamen-mimicking structures set a stronger trigger for grooming than real stamens. In addition we will test if feeding stamens induce grooming more strongly than pollination stamens in heterantherous flowers. These experiments will show if flowers are able to manipulate the bees grooming by tactile cues in order to promote pollen transfer to conspecific flowers. The coherent aspect of these studies is the fine-tuned floral filter by which bee-pollinated flowers might be able to exclude distinct bees and thereby improve pollination success. These studies will focus on currently understudied antagonistic aspects of the mutualism between flower-visiting bees and melittophilous flowering plants.

蜜蜂被认为是可靠的传粉者；蜜蜂访花的频率和花的稳定性证实了这一点，但蜜蜂收集花粉为幼虫提供食物却提出了质疑。已经进入花粉运输结构的花粉粒不再用于授粉。这种分配花粉用于授粉以外的目的，对蜜蜂授粉的开花植物来说是一种困境。在这个项目中，我们将通过测试花是否以及如何操纵蜜蜂来优化花粉传递来研究花粉困境的三个迄今尚未研究和连贯的方面。1. 花粉粒的刺参与了防止花粉粒被圆孔蜜蜂收集的机械防御。我们将测试棘数、棘长、花粉颗粒直径、花粉水合作用和添加反流花蜜的作用，以了解刺花粉抵抗圆孔蜂采集的机制。此外，我们将测试开花植物是否使用带刺的花粉粒来限制蜜蜂采集花蜜，因为采集花蜜的蜜蜂梳理自己的频率较低。2. 在蜜蜂身体的安全位置上的花粉粒被整理成花粉运输结构的可能性较小，因为它们不能从那里给花授粉。我们将测试龙骨花是否代表一个例外，是否可以使用scopa作为一种传粉蜜蜂的安全地点。我们将测试龙骨花的硬度是否代表了一种花卉适应，以促进花粉粒从蜜蜂的腹侧镜转移到花的柱头。龙骨花只能由巨型蜜蜂开放。这将是由可育的镜镜花粉授粉的第一个证据，并对各自的花构成强大的选择压力，以排除不具有腹侧镜镜的蜜蜂。3. 许多蜜蜂授粉的花具有模仿花粉和雄蕊的结构，这些结构被认为是视觉花卉指南的功能。我们将研究尚未探索的花粉和雄蕊模仿结构的功能，通过触觉刺激触发蜜蜂的梳理行为。我们将测试一个假设，即雄蕊模仿结构比真正的雄蕊更能触发修饰。此外，我们将测试在异种花中，取食雄蕊是否比授粉雄蕊更强烈地诱导修饰。这些实验将显示花朵是否能够通过触觉提示操纵蜜蜂的梳理，以促进花粉向同种花朵的转移。这些研究的一致之处在于，蜜蜂授粉的花朵可以通过微调花朵过滤器来排除不同的蜜蜂，从而提高授粉的成功率。这些研究将集中在目前尚未充分研究的访花蜜蜂和嗜蜂开花植物之间相互作用的拮抗方面。