The importance of the uplift of the Qinghai-Tibetan Plateau for the subtribe Gentianinae (Gentianaceae): the relative contribution of in situ speciation versus colonisation

该项目旨在研究导致在青藏高原（QTP）山区建立高水平生物多样性的进化过程。人们通常认为，QTP的隆起引发了许多植物谱系的适应性辐射。然而，在隆起和生物反应（多样化）之间有一个显着的延迟，这表明地质过程本身不能解释在这一地区观察到的生物多样性的积累。气候振荡驱动的物种泵效应和倍性水平的变化都可能促进了物种的多样性。气候生态位演化的研究将提供迹象表明，气候生态位偏好的变化是否促进了物种丰富的属，龙胆（龙胆科），这已被证明是起源于该地区的QTP的多样化。此外，将对冰川和间冰期进行物种分布建模（基于发生率和Worldclim数据），以评估QTP地区气候振荡期间范围扩张/收缩的程度和物种泵效应。类似的分析将进行一个分支的落基山脉，允许这些山区系统之间的比较。在气候建模人员的支持下，将进一步完成冰川和间冰期物种分布建模（总体项目提案A），通过精细的地理分析，以确定出西藏的主要传播路线。由于这些路线可能会有所不同，根据生态的一个类群，三个亚支与对比生态（代表两到三个热带）内龙胆将进行比较。在本研究过程中，我想回答以下问题：（1）龙胆属植物十字花组/龙胆属植物的分化率是否发生了变化？气候生态位需求的这种变化是否与生物群落分布随时间的变化相对应？(2)与对比生态的血统（G。在不同的气候条件下，通过不同的传播途径，Cruciata和Acoustonanthe，Frigida，Monopopopotera）传播出QTP？(3)QTP和北美的山区是否分别在姐妹区Cruciata（主要是QTP）和Arabonanthe（主要是北美）中充当物种泵？(4)多倍体比二倍体有更广的气候生态位吗？

This project is designed to study evolutionary processes that lead to the establishment high levels of biodiversity in the mountainous region of the Qinghai-Tibetan Plateau (QTP). It is often assumed that the uplift of the QTP triggered adaptive radiations in many plant lineages. Yet, there is a remarkable delay between uplift and biological response (diversification), indicating that geological processes alone cannot explain the observed accumulation of biodiversity in this region. Among others, the species pump effect driven by climate oscillation, and variations of ploidy levels might both have fostered diversification.Climatic niche and ploidy evolution will be investigated in the light of phylogenies derived from High-Throughput sequence data. The study of climatic niche evolution will provide indications whether shifts in climatic niche preferences promoted the diversification of a species-rich genus, Gentiana (Gentianaceae), which has been shown to originate in the region of the QTP. Furthermore, species distribution modelling (based upon occurrence and Worldclim data) will be performed for glacials and interglacials in order to evaluate the extent of range expansion/contraction, and the species pump effect during climate oscillations in the QTP region. Similar analyses will be performed for a clade of the Rocky Mountains, allowing to compare between these mountain systems. Species distribution modelling for glacials and interglacials, performed with the support of climate modellers (umbrella project proposal A), will be further completed by refined biogeographical analyses in order to identify major dispersal routes out of Tibet. Because these routes might vary according to the ecology of a taxon, three subclades with contrasting ecology (representing two to three thermal belts) within Gentiana will be compared. In the course of this study, I want to answer the following questions: (1) Is the shift in diversification rates in the lineage Gentiana sect. Cruciata/G. sect. Pneumonanthe associated with a shift in climatic niche requirements, and does this shift in climatic niche requirements correspond to variation of biome distribution through time? (2) Did lineages with contrasting ecology (G. sections Cruciata and Pneumonanthe, Frigida, Monopodiae) disperse out of the QTP under different climatic conditions and by different dispersal routes? (3) Did the mountainous regions of the QTP and North America act as species pumps in the sister sections Cruciata (mainly QTP), and Pneumonanthe (mainly North America), respectively? (4) Do polyploids have a broader climatic niche than diploids?