A temperate radiation in a tropical plant family – factors underpinning evolution of the Eurasian Vincetoxicum (Apocynaceae) complex

温带草本植物的分支，主要是热带，木本被子植物的家庭往往经历了加速事件的物种多样化和/或分化-辐射-在最近的过去，经常与新的栖息地的殖民化。然而，在一些研究得很好的地理热点之外，人们对驱动这种辐射的因素知之甚少，例如，山或岛屿。夹竹桃科（Apocynaceae）的萝摩亚科（Asclepiadoideae）是一个具有花粉形成功能的热带亚科，在温带地区只有3个谱系经历了大量的辐射，其中萝摩属（A.e.l.）是最年轻的Escherichotoxicum是一个由几个热带藤本分支和两个草本温带辐射组成的属。其中之一，“乙酰胆碱S. STR。“进化枝，已经从远东通过亚洲山脉扩展到亚洲草原和欧洲，从那里它已经进入新世界的新手。为了了解这种现代温带辐射的演化历史，我们将研究三种证据：形态测量，分子和化学。特别是，我们测试的最有可能的因素之一，有助于这个分支的进化成功，其不寻常的化学特征菲并吲哚里西啶生物碱（皮亚斯）。综合分析将阐明该分支的表型变异、遗传基础和假定的化学防御策略，以检验最成功的谱系是具有最佳化学防御系统的谱系的假设。我们将（1）开发一个全面的形态学数据集，以界定“形态种”;（2）使用低拷贝核基因的靶向测序，提供一个密集采样的Escherichoticum s. str. clade的进化史，以界定基于聚结的种;（3）检查形态种和聚结种的一致性-的物种，并得出一个稳定的物种概念，为欧亚Eurasian Eustoxicum的基础上不同的证据线;一个工具，迫切需要为未来的监测Eustoxicum在气候变化和保护;（4）以皮亚斯的数量和多样性作为防御强度的指标，检验最成功的物种是具有最好的化学防御系统的物种的假设。

Temperate herbaceous clades in mainly tropical, woody Angiosperm families often have undergone accelerated episodes of species diversifications and / or disparification – radiations – in the recent past, frequently associated with the colonization of new habitats. However, little is known about the factors driving such radiations outside some well-studied biogeographic hotspots like, e.g., mountains or islands. In the pollinia-forming, tropical subfamily Asclepiadoideae of Apocynaceae, only three lineages have undergone a substantial radiation in the temperate zones, of which Vincetoxium (s.l.) is the youngest one. Vincetoxicum is a genus comprising several tropical lianescent clades and two herbaceous temperate radiations. One of these, the "Vincetoxicum s.str." clade, has expanded from the Far East via the Asian mountain chains into the Asian steppes and into Europe, from where it has entered the New World with neophytes. To understand the evolutionary history of this recent temperate radiation, we will study three lines of evidence: morphometric, molecular, and chemical. Especially, we test one of the most likely factors contributing to the evolutionary success of this clade, its unusual chemistry featuring phenanthroindolizidine-alkaloids (PIAs). Synthetic analysis will elucidate the phenotypic variation, the genetic basis, and the supposed chemical defence strategy in this clade to test the hypothesis that the most successful lineages are the ones with the best chemical defence system. We will (1) develop a comprehensive morphological dataset allowing the delimitation of "morphospecies"; (2) provide a densely sampled phylogeny of the Vincetoxicum s.str. clade using targeted sequencing of low-copy nuclear genes, allowing the delimitation of coalescent-based species; (3) check the congruence of morphospecies and coalescent-based species and derive a stable species concept for Eurasian Vincetoxicum based on different lines of evidence; a tool urgently needed for future monitoring of Vincetoxicum in the light of climate change and conservation; (4) test the hypothesis that the most successful species are the ones with the best chemical defence system, using quantity and diversity of PIAs as a proxy for the strength of the defence.