Nunes Carlos E P, Wolowski Marina, Pansarin Emerson Ricardo, Gerlach Günter, Aximoff Izar, Vereecken Nicolas J, Salvador Marcos José, Sazima Marlies
Programa de Pós-Graduação em Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, C.P. 6109, Campinas, SP, 13083-970, Brazil.
Instituto de Ciências da Natureza, Universidade Federal de Alfenas, Alfenas, MG, 37130-001, Brazil.
Naturwissenschaften. 2017 Oct 13;104(11-12):92. doi: 10.1007/s00114-017-1511-3.
Floral volatile organic compounds (VOCs) play important roles in plant-pollinator interactions. We investigated the reproductive ecology and floral VOCs of Zygopetalinae orchids to understand the relationship between floral scents and pollinators. We performed focal observations, phenological censuses and breeding system experiments in eight species in southeast Brazil. Floral scents were collected and analysed using SPME/GC-MS. We performed multivariate analyses to group species according to affinities of their VOCs and define compounds associated to each plant. Dichaea cogniauxiana was pollinated by weevils which use their developing ovules, while D. pendula was pollinated by the same weevils and perfume-collecting male euglossine bees. The other species were deceit-pollinated by bees. Zygopetalum crinitum was pollinated by carpenter bees, while W. warreana, Z. mackayi and Z. maxillare were bumblebee-pollinated. The latter was also pollinated by Centris confusa. Breeding system varied widely with no association to any pollinator group. Most VOCs are common to other floral scents. Zygopetalum crinitum presented an exclusive blend of VOCs, mainly composed of benzenoids. The scents of Pabstia jugosa, Promenaea xanthina and the Zygopetalum spp. were similar. The bumblebee-pollinated species have flowering periods partially overlapped, thus neither phenology nor pollinators constitute hybridization barriers among these species. Euglossines are not the only pollinators of Zygopetalinae. Different VOCs, size and lifespan of flowers are associated with distinct pollinators. A distinctive VOC bouquet may determine specialisation in carpenter bees or male euglossines within bee-pollinated flowers. Finally, visitation of deceit-pollinated flowers by perfume-collecting euglossines allows us to hypothesise how pollination by this group of bees had evolved.
花卉挥发性有机化合物（VOCs）在植物与传粉者的相互作用中发挥着重要作用。我们研究了合萼兰亚族兰花的繁殖生态学和花卉VOCs，以了解花香与传粉者之间的关系。我们在巴西东南部的八个物种中进行了定点观察、物候普查和繁育系统实验。使用固相微萃取/气相色谱-质谱联用仪（SPME/GC-MS）收集并分析花香。我们进行了多变量分析，根据VOCs的亲和力对物种进行分组，并确定与每种植物相关的化合物。认知双叶兰由利用其发育中的胚珠的象鼻虫传粉，而垂花双叶兰则由相同的象鼻虫和采集香水的雄性 Euglossine 蜜蜂传粉。其他物种则由蜜蜂进行欺骗性传粉。毛唇合萼兰由木蜂传粉，而沃氏合萼兰、马克氏合萼兰和大花合萼兰则由熊蜂传粉。后者也由混淆无垫蜂传粉。繁育系统差异很大，与任何传粉者群体均无关联。大多数VOCs与其他花香相同。毛唇合萼兰呈现出独特的VOCs混合物，主要由苯类化合物组成。朱戈帕氏兰、黄褐普罗梅纳兰和合萼兰属植物的气味相似。熊蜂传粉的物种花期部分重叠，因此物候和传粉者都不会在这些物种之间构成杂交障碍。Euglossine蜜蜂不是合萼兰亚族的唯一传粉者。不同的VOCs、花朵大小和寿命与不同的传粉者相关。独特的VOC组合可能决定了木蜂或蜜蜂传粉花朵中雄性Euglossine蜜蜂的专一性。最后，采集香水的Euglossine蜜蜂对欺骗性传粉花朵的访问使我们能够推测这组蜜蜂的传粉是如何进化的。
