Plasticity of a range-expanding Brassicaceae and impact on natural enemies

植物生物入侵的研究主要集中在跨洋分布区扩展的物种，而大陆内植物的分布区扩展一直被忽视。然而，由于气候变化等原因，这种陆内分布范围的扩大可能变得越来越重要。与横贯大陆的入侵者相比，陆内分布区扩展者可能不会完全被天敌释放，但天敌群落在该物种的本地和非本地分布区仍可能有所不同。此外，入侵植物物种可能表现出较高的表型可塑性，并在化学和形态性状的依赖网站的硝酸盐的可用性。在这个项目中，我的目标是我。确定分布区扩展植物种沿着分布区种群的遗传多样性，II.调查植物来源和硝酸盐施肥对根和芽生长和防御性状的影响，和III.评估植物表型差异与相互作用生物（食芽生物、侵染芽的真菌、食根生物）的相关性。作为模型系统，我提出了Eschericaceae Bunias orientalis，这是扩大其范围向西欧，特别是入侵肥沃和干扰的网站。探讨B的遗传变异和表型可塑性。在两种硝酸盐施肥条件下，将来自本地、外来和入侵范围的不同种群的植物种植在共同的花园中。用扩增片段长度多态性方法测定居群内和居群间的遗传多样性。芽和根的组成性防御和生长模式将以综合方法确定，测量各种形态和化学参数。在物种内发现的植物防御和生长综合征的差异的相关性将以两种方式确定。在田间试验中，将连续两年观察攻击不同植物的食草动物和病原体群落。在一项实验室研究中，将使用一种叶食草动物、一种叶病原体和一种根食草动物作为潜在的拮抗剂来确定来自不同来源并在不同施肥条件下生长的植物的抗性。将这个项目的不同部分联系起来，将使我能够确定哪些植物性状对与潜在敌人的互动最具决定性。我假设，高度多样化的植物种群可能是最好的防御敌人，这可能是一个重要的成功策略的植物入侵者。

Biological plant invasions have been studied mainly in transoceanic range expanding species, whereas the range-expansion of plants within continents has been neglected. However, such intracontinental range-expansion may become increasingly important, for example, due to climate change. The intracontinental range-expanders may, in contrast to the transcontinental invasives, not be entirely released by natural enemies, but the enemy community may still differ in the native and non-native distribution areas of the species. Furthermore, invasive plant species may show high phenotypic plasticity and differ in chemical and morphological traits in dependence of the nitrate availability of the site. In this project, I aim to I. determine the genetic diversity of populations of a range-expanding plant species along the distribution range, II. investigate the effects of plant origin and nitrate fertilisation on root and shoot growth and defence traits, and III. evaluate the relevance of differences in plant phenotypes for interacting organisms (shoot-feeders, shoot-infesting fungi, root-feeders). As model system, I propose the Brassicaceae Bunias orientalis, which is spreading its range towards Western Europe and is particularly invading fertile and disturbed sites. To characterise the genetic variation and phenotypic plasticity of B. orientalis, plants of different populations from the native, exotic, and invasive range will be grown in a common garden under two nitrate fertilisation conditions. The genetic diversity within and among populations will be determined by amplified fragment length polymorphism. The constitutive defence and growth pattern of shoots as well as roots will be determined in a comprehensive approach, measuring various morphological and chemical parameters. The relevance of differences in plant defence and growth syndromes found within the species will be determined in two ways. In a field-experiment, the herbivore and pathogen community attacking the different plants will be observed over two consecutive years. In a laboratory study, the resistance of plants from different origin and grown under different fertilisation will be determined using a leaf-herbivore, a leaf-pathogen and a root-herbivore as potential antagonists. Relating the different parts of this project will enable me to determine which plant traits are most decisive for interactions with potential enemies. I hypothesise that highly diverse plant populations may be best defended against enemies and that this may be an important success strategy of plant invaders.