Ecology and evolution of floral scents in the perfume flowers

所谓的“香水花”的花朵产生的花香仅由雄性兰花蜂（Euglossini: Apidae）收集，并在求偶时向雌性表明它们的健康/身份（物种）。最近的研究表明，这些植物的花香进化是由其真实传粉者预先存在的感官偏见所塑造的。然而，对此的实验支持仍然存在争议。20世纪60年代至90年代，人们对雄兰蜂授粉植物的花香化学成分及其在吸引传粉者中的作用进行了深入研究。然而，目前的估计表明，超过80%的香水花物种的传粉者身份（在特定水平上）和化学成分仍然未知。显然，由于对传粉媒介和花香化学信息的有限，所涉及的植物类群的系统发育尚未解决，以及对eugine传粉媒介的感觉/行为偏好的初步了解，使得对香水花与其传粉媒介相互作用的生态和进化机制的更全面理解变得困难。在本提案中，我们旨在了解花香的生态和进化意义。为此，我们将利用不同学科的现代技术，如化学生态学、授粉生物学、行为生态学、昆虫生理学和分子系统发育。目前有关传粉媒介和花香化学成分的知识将在文献的系统综述中进行汇编。为了增加互动的知识，花卉参观者将直接收集鲜花。收集的花香样本将用于生物分析和化学分析。将利用触角电图（EAG）分析调查传粉者的感觉（嗅觉）偏差，并在野外对雄性兰蜂进行行为生物测定。基于GenBank中的分子数据，将重建与香水花相关的物种及其传粉者的系统发育关系。通过这种综合方法，我们将测试关于香水花的花属性宏观进化的基本假设。该项目采用多学科方法，由来自不同院校的经验丰富的研究人员组成，促进加强已建立和成功的国际合作和学生交流。这个项目将帮助我们对雄性兰花蜜蜂和香水花相互作用的自然历史的基本知识做出贡献，并了解花香在这种互惠关系的生态学和进化中的重要性。

Flowers of the so-called “perfume flowers” produce floral scent that is collected exclusively by male orchid bees (Euglossini: Apidae) and used to signal their fitness/identity (species) to females during courtship display. Recent studies suggest that the evolution of floral scents in these plants is shaped by preexisting sensory biases of their euglossine pollinators. However, experimental support for this is still controversial. The chemical composition of floral scents in plants pollinated by male orchid bees, as well as their role in attracting pollinators, was intensively studied between the 1960s and 1990s. Nevertheless, current estimates suggest that pollinator identity (at the specific level) and the chemical composition of more than 80 % of all species with perfume flowers remain unknown. Obviously, the limited information about pollinators and floral scent chemistry, the unresolved phylogeny of the plant taxa involved and an incipient understanding of the sensory/behavioral biases of euglossine pollinators, make it difficult to have a more comprehensive understanding of the ecological and evolutionary mechanisms that govern the interactions between perfume flowers and their pollinators. In the present proposal, we aim at understanding the ecological and evolutionary meaning of floral perfumes. For this, we will use modern techniques from various disciplines, such as chemical ecology, pollination biology, behavioral ecology, insect physiology and molecular phylogeny. Current knowledge about pollinators and about the chemical composition of floral perfumes will be compiled in a systematic review of the literature. In order to add to the knowledge of the interactions, floral visitors will be collected directly on flowers. The floral scent samples will be collected and used for bioassays and chemical analyses. Sensory (olfactory) biases of pollinators will be investigated using electroantenographic (EAG) analyzes, and behavioral bioassays in the field will be performed with male orchid bees. The phylogenetic relationships of species with perfume flowers, as well as their pollinators will be reconstructed based on molecular data available in GenBank. With this integrative approach, we will test fundamental hypotheses about the macroevolution of floral attributes in perfume flowers as a whole. In view of its multidisciplinary approach, this project will involve an experienced team of researchers from different institutions, promoting the strengthening of well-established and successful international cooperation and the exchange of students. This project will help us to both contribute to the scanty knowledge on basic aspects of the natural history of the specialized interaction involving male orchid bees and perfume flowers and understand the significance of floral scents in the ecology and evolution of this mutualism.