Olfactory cues constitute one of the most important plant-pollinator communication channels. Specific chemical components can be associated with specific pollinator functional groups due to pollinator-mediated selection on flower volatile (FV) emission. Here, we used multivariate analyses of FV data to detect an association between FVs and the worldwide distributed pollinator group of the carpenter bees (Xylocopa spp.). We compiled FVs of 29 plant species: 9 pollinated by carpenter bees, 20 pollinated by other bee pollinator functional groups. We tested whether FV emission differed between these groups. To rule out any phylogenetic bias in our dataset, we tested FV emission for phylogenetic signal. Finally, using field assays, we tested the attractive function of two FVs found to be associated with carpenter bees. We found no significant multivariate difference between the two plant groups FVs. However, seven FVs (five apocarotenoid terpenoids, one long-chain alkane and one benzenoid) were significantly associated with carpenter bee pollination, thus being “predictor” compounds of pollination by this pollinator functional group. From those, β-ionone and (E)-methyl cinnamate presented the highest indicator values and had their behavioural function assessed in field assays. Phylogenetic signal for FVs emission was weak, suggesting that their emission could result from pollinator-mediated selection. In field assays, the apocarotenoid β-ionone attracted carpenter bees, but also bees from other functional groups. The benzenoid (E)-methyl cinnamate did not attract significant numbers of pollinators. Thus, β-ionone functions as a non-specific bee attractant, while apocarotenoid FVs emerge as consistent indicators of pollination by large food-foraging bees among bee-pollinated flowers.

嗅觉线索构成了最重要的植物传粉媒介沟通渠道之一。由于传粉媒介介导的花挥发性 (FV) 发射选择，特定的化学成分可能与特定的传粉媒介官能团相关联。在这里，我们使用 FV 数据的多变量分析来检测 FV 与全球分布的木蜂（Xylocopa属）。我们编制了 29 种植物物种的 FV：9 种由木蜂授粉，20 种由其他蜜蜂授粉功能组授粉。我们测试了这些组之间的 FV 发射是否不同。为了排除我们数据集中的任何系统发育偏差，我们测试了系统发育信号的 FV 发射。最后，我们使用现场分析测试了发现与木蜂相关的两个 FV 的吸引力功能。我们发现两个植物组 FV 之间没有显着的多变量差异。然而，七种 FV（五种类胡萝卜素萜类化合物、一种长链烷烃和一种苯类）与木蜂授粉显着相关，因此是该授粉者官能团授粉的“预测”化合物。其中，β-紫罗兰酮和（E)-肉桂酸甲酯显示出最高的指标值，并在现场分析中评估了它们的行为功能。FVs 发射的系统发育信号很弱，表明它们的发射可能是由传粉媒介介导的选择引起的。在田间试验中，类胡萝卜素 β-紫罗兰酮吸引了木蜂，但也吸引了来自其他官能团的蜜蜂。苯环 ( E )-肉桂酸甲酯没有吸引大量传粉者。因此，β-紫罗兰酮作为一种非特异性的蜜蜂引诱剂起作用，而类胡萝卜素 FV 则作为大型觅食蜜蜂在蜜蜂授粉的花朵中进行授粉的一致指标而出现。