Evolution and phylogenetic systematics of the sexually dimorphic orchid genus Cycnoches

苏铁属（Cycnoches，Catasetinae）植物是少数具有两性花功能的兰科植物之一，对研究兰科植物生殖机制的进化具有重要意义。Cycnoches属包括C。34种分布于墨西哥南部至巴西及玻利维亚，主要栖息于低地潮湿森林。虽然在过去的几个世纪里，这个群体吸引了一些科学家的注意，但人们对它的多样性和进化知之甚少。本项目将产生质体和核发育，包括高达90%的所述物种，特别强调那些发生在新热带区研究和采样不足的地区。将产生一个过时的系统发育史，并将进行主要分支的系统地理重建。我们的主要目标是：1）在亚部落水平上确定Cynoches精确系统位置及其物种系统发育关系; 2）通过下一代测序和化学分类方法进行物种界定（重点是分类学上具有挑战性的类群，如Cycnoches egertonianum物种复合体）; 3）了解性二型的进化;（4）阐明了安第斯山脉的抬升对苏铁属主要分支演化的影响。研究结果将有助于一个完整的专着属。这一跨学科研究项目的成果将揭示重要的地理/生物事件的影响，以及相关的因此知之甚少的新热带兰花群体的演变。此外，它将作为一个模型，以解决其他分类学问题和研究不足的兰花属，如Catasetum和Mormodes。

As one of the few orchid genera with functionally sexual dimorphic flowers, Cycnoches (Catasetinae) species have special importance in understanding the evolution of reproductive mechanisms in Orchidaceae. The genus Cycnoches encompasses c. 34 species distributed from S Mexico to Brazil and Bolivia, which inhabit mostly lowland wet forests. Although this group has attracted the attention of several scientists during the last centuries, its diversity and evolution is poorly understood. A plastid and nuclear phylogeny will be generated in this project including up to 90% of the described species with special emphasis on those occurring in poorly studied and sampled regions of the Neotropics. A dated phylogeny will be generated and a reconstruction of the biogeography of major clades will be carried out. Our main goals are: 1) Determining the precise systematic placement of Cycnoches at the subtribal level and phylogenetic relationships of its species; 2) species delimitation by means of next generation sequencing and chemotaxonomical approaches (with emphasis on taxonomically challenging taxa such as the Cycnoches egertonianum species complex); 3) understanding the evolution of sexual dimorphism; and 4) elucidating the impact of the raising Andes in the evolution of the major clades of Cycnoches. The results will contribute to a complete monograph of the genus. The outcomes of this interdisciplinary research project will shed light on the influence of important geographic/biological events and the evolution of related hence poorly understood Neotropical orchid groups. Moreover, it will serve as a model to tackle other taxonomically problematic and understudied orchid genera such as Catasetum and Mormodes.