The evolutionary history of Hypericum perforatum L.

金丝桃属是一个形态学和生态学高度分化的大类群，有460多个种。有几个物种广泛分布于欧亚大陆，主要分布在不受极端环境因素影响的低地栖息地。贯叶连翘和H. maculatum是代表性的例子，具有很大程度上重叠的分布区，但第一种往往喜欢干燥的栖息地，而第二种甚至分布在欧亚大陆北部地区。我们的目标是解开这两个广泛分布的低地物种在更新世（地理学）的进化历史，并反映实际和过去的基因流两者之间的遗传接触区的特点。我们想验证这种广泛分布的低地物种的进化情景是否证实了从木本植物、一年生植物、北极高山代表植物和其他植物的分析中揭示的避难区和主要迁移路线的模式。perforatum和H.这也是显而易见的，在两个物种群体之间存在着正在进行的基因流。该项目是嵌入在一个更大的研究网络集中在金丝桃属的进化和系统学的一般，但选择H。作为模式，重点放在进化的重要性状和字符。本研究的结果是讨论金丝桃属植物一个重要性状进化的前提，即无融合生殖，即通过无性别产生的种子进行繁殖。这项研究将提供有关以下方面的基本信息：1）遗传多样性中心，2）遗传变异的迁移路线和来源地区，3）杂交和缝合区，以及4）多样性的时间估计。所有这些信息都可以与实际分析的种群内的性状无融合生殖联系起来，并应回答以下问题：1）无融合生殖的多源和构成（在空间和时间上），2）性状通过杂交桥的传递，3）从有性繁殖到无性繁殖以及从无性繁殖到有性繁殖的适应和过渡的时间动态。

The genus Hypericum is a morphologically and ecologically highly diverged and large group of more than 460 species. Several species are wide-spread in Eurasia and dominate in lowland habitats not affected by extreme environmental factors. Hypericum perforatum and H. maculatum are representative examples with a largely overlapping distribution area, but the first one tends to prefer drier habitats, while the second species is distributed even in boreal Eurasian regions. We aim to unravel the evolutionary history of these two wide-spread lowland species during the pleistocene (phylogeography) and to characterize genetical contact zones reflecting actual and past geneflow between both. We would like to test if this evolutionary scenario of the wide-spread lowland species confirm patterns of refuge areas and principle migration routes revealed from the analysis of woody plants, annuals, arcticalpine representatives and others.It is very likey that hybridization and reticulation played a role in the evolution of different morpho- and cytotypes in H. perforatum as well as in H. maculatum, and it is also obvious, that there is ongoing geneflow between both species groups. This project is embedded in a larger research network focusing on the evolution and systematics of Hypericum in general, but selecting H. perforatum and closest relatives as model to focus on evolutionary important traits and characters. The results from this study are a prerequisite to discuss the evolution of one important trait in Hypericum, namely apomixis, the propagation via seeds produced without sexuality. This study will provide fundamental information about 1) centres of genetic diversity, 2) migration routes and source areas of genetic variation, 3) hybridization and suture zones, and 4) temporal estimates of diversification. All these information can be linked with the trait apomixis within populations actually analysed in detail and should answer questions about 1) multiple origin and constitution of apomixis (in space and time), 2) transmission of the trait via hybrid bridges, and 3) temporal dynamics of adaptation and transition from sexual to asexual propagation and wee versa.