Evolution and phylogenetic systematics of the sexually dimorphic orchid genus Cycnoches

锦鸡儿属(Catasetinae)兰科植物是兰科植物中为数不多的开二型性花的兰科植物之一，对了解兰科植物生殖机制的进化具有特殊的意义。Cycnoches属包括约34种，分布于从S墨西哥到巴西和玻利维亚，主要生活在低地潮湿的森林。尽管在过去的几个世纪里，这一群体吸引了几位科学家的注意，但人们对其多样性和进化知之甚少。本项目将建立一个叶绿体和核的系统发育图，包括高达90%的描述物种，并特别强调那些出现在研究较少和采样较少的新热带地区的物种。将生成一个过时的系统发展史，并将重建主要支系的生物地理。我们的主要目标是：1)确定Cycnoch在亚部落水平上的精确系统位置及其物种的系统发育关系；2)通过下一代测序和化学分类方法(重点是分类上具有挑战性的分类单元，如Cycnoches egertonianum物种复合体)进行物种划分；3)了解性别二型性的进化；以及4)阐明隆起的安第斯山脉在Cycnoch主要分支进化中的影响。这些结果将有助于形成一本完整的该属专著。这一跨学科研究项目的结果将阐明重要的地理/生物事件的影响，以及相关的、因此鲜为人知的新热带兰花种群的演变。此外，它还将作为一个模式来解决其他分类上有问题和研究不足的兰属，如香兰属和莫莫斯属。

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.