Institute of Sensory Ecology, Heinrich-Heine University Düsseldorf, Germany.
School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia.
Ann Bot. 2021 Nov 9;128(7):821-824. doi: 10.1093/aob/mcab088.
Colour pattern is a key cue of bee attraction selectively driving the appeal of pollinators. It comprises the main colour of the flower with extra fine patterns, indicating a reward focal point such as nectar, nectaries, pollen, stamens and floral guides. Such advertising of floral traits guides visitation by the insects, ensuring precision in pollen gathering and deposition. The study, focused in the Southwest Australian Floristic Region, aimed to spot bee colour patterns that are usual and unusual, missing, accomplished by mimicry of pollen and anthers, and overlapping between mimic-model species in floral mimicry cases.
Floral colour patterns were examined by false colour photography in 55 flower species of multiple highly diverse natural plant communities in south-west Australia. False colour photography is a method to transform a UV photograph and a colour photograph into a false colour photograph based on the trichromatic vision of bees. This method is particularly effective for rapid screening of large numbers of flowers for the presence of fine-scale bee-sensitive structures and surface roughness that are not detectable using standard spectrophotometry.
Bee- and bird-pollinated flowers showed the expected but also some remarkable and unusual previously undetected floral colour pattern syndromes. Typical colour patterns include cases of pollen and flower mimicry and UV-absorbing targets. Among the atypical floral colour patterns are unusual white and UV-reflecting flowers of bee-pollinated plants, bicoloured floral guides, consistently occurring in Fabaceae spp., and flowers displaying a selective attractiveness to birds only. In the orchid genera (Diuris and Thelymitra) that employ floral mimicry of model species, we revealed a surprising mimicry phenomenon of anthers mimicked in turn by model species.
The study demonstrates the applicability of 'bee view' colour imaging for deciphering pollinator cues in a biodiverse flora with potential to be applied to other eco regions. The technique provides an exciting opportunity for indexing floral traits on a biome scale to establish pollination drivers of ecological and evolutionary relevance.
颜色模式是吸引蜜蜂的关键线索，它选择性地驱动着传粉媒介的吸引力。它由花朵的主要颜色和额外的精细图案组成，指示着花蜜、蜜腺、花粉、雄蕊和花引导等奖励焦点。这种对花卉特征的宣传引导昆虫来访，确保花粉采集和沉积的精确性。本研究集中在澳大利亚西南部植物区系，旨在发现蜜蜂通常和不寻常的颜色模式，以及由于花粉和雄蕊的模拟以及在花卉模拟案例中模拟-模型物种之间的重叠而缺失的颜色模式。
通过在澳大利亚西南部的 55 种多种高度多样化的自然植物群落的花朵上进行假彩色摄影，检查花朵的颜色模式。假彩色摄影是一种将紫外线照片和彩色照片转换为基于蜜蜂三色视觉的假彩色照片的方法。这种方法对于快速筛选大量花朵中细小的蜜蜂敏感结构和表面粗糙度特别有效，而这些结构和粗糙度是使用标准分光光度法无法检测到的。
传粉者为蜜蜂和鸟类的花朵表现出预期的，但也有一些显著的和以前未检测到的不寻常的花卉颜色模式综合征。典型的颜色模式包括花粉和花朵模拟以及紫外线吸收目标的情况。在非典型的花卉颜色模式中，有不寻常的白色和紫外线反射花朵为蜜蜂授粉植物，双色花引导，在豆科植物中一致出现，以及只对鸟类具有选择性吸引力的花朵。在采用模型物种的花卉模拟的兰花属（Diuris 和 Thelymitra）中，我们揭示了一个令人惊讶的现象，即模型物种的雄蕊依次被模拟。
本研究证明了“蜜蜂视角”彩色成像在破译具有生物多样性的植物群中的传粉媒介线索的适用性，有可能应用于其他生态区。该技术为在生物群落尺度上索引花卉特征提供了一个令人兴奋的机会，以确定具有生态和进化相关性的授粉驱动因素。
