Contemporary evolution and phenotypic plasticity or genetic fixation: Rates of evolution and adaptive processes in populations under novel selection regimes

该项目的目的是评估影响表型可塑性或/和遗传固定的当代进化过程的重要性，并评估它们对植物在新的和多重选择压力下的适应能力和持久性的重要性。当代进化的程度和时间将通过使用植物园（BG）中作为迁地收集管理的五种不同植物物种的种群来研究，从而形成一个研究系统，可以精确确定由于选择制度的一致变化而导致的表型和遗传变化。我们将比较15个创始种群（在BGs中培养了几代）在一定时间内暴露于新的选择压力下与其原始野生源种群。我们将利用高通量测序产生的限制性内切位点相关DNA标签（RAD标签）分析BG和野生源群体的遗传多样性，并通过生活史性状的比较评估表型多样性。为了比较适应度参数和适应极限在变化条件和多种胁迫因素下的变化，所有种群被交替移植到所有的野生和园林场地，在一个共同的园林实验中，相同的同父异母兄弟姐妹家庭被实验暴露于扰动，即新的环境条件。因此，局部适应、表型可塑性和遗传多样性的数量和相互关系与暴露于新环境条件的时间有关，可以进行评估。

The aim of this project is to assess the importance of contemporary evolutionary processes influencing phenotypic plasticity or/and genetic fixation and to assess their importance for the adaptive capacity and persistence of plants under novel and multiple selection pressures. The extent and timing of contemporary evolution will be studied by using populations of five different plant species that are managed as ex-situ collections in botanical gardens (BG) hence forming a study system that allows a precise determination of phenotypic and genetic changes due to a consistent change in selection regime. We will compare 15 founder populations (cultivated for several generations in BGs) exposed to novel selection pressures for a defined amount of time with their original source populations in the wild. We will analyse 1) genetic diversity of BG and wild source populations by using restriction site-associated DNA tags (RAD tags) generated by high-throughput sequencing and 2) assess phenotypic diversity by comparison of life-history traits. To compare fitness parameters and limits of adaptation under changing conditions und multiple stress factors, all populations are reciprocally transplanted to all wild and garden sites and, in a common garden experiment, the same half-sib families are experimentally exposed to perturbations, i.e. to new environmental conditions. Thereby, the amount and interrelationship of local adaptation, phenotypic plasticity and genetic diversity in relation to the time since exposure to novel environmental conditions can be evaluated.