Experimental evolution of the co-adaptation of mais and its pathogen Exserohilum turcicum

现代农业生态系统的特点是生态多样性低。这导致相互作用的物种（如农作物和它们的害虫）之间存在强大的进化选择压力。玉米是世界上种植最广泛的作物物种之一，由于其高度的品种多样性和基因组变异性，是研究农业生态系统进化过程的一个非常合适的模型。在一项为期数年的实验中，将研究玉米及其最重要的病原体之一——turcicum exserhilum。这种真菌引起北方叶枯病并蔓延到整个中欧。将接种两种不同的玉米品种，它们对真菌的抗性不同，并选择抗性最强的植物。真菌将被种群分离并转移到下一代。这就产生了玉米与病原菌群体共同适应的强大选择压力。在三个计划选择周期的每一个周期中，玉米和病原菌群体将用群体遗传学方法进行基因分型和调查。该分析旨在测试病原体的进化是否因不同的宿主种群而不同，以及哪种进化模型最能描述宿主和病原体种群的变化。通过这样的比较，可以对作物及其有害生物的遗传多样性对共同进化的重要性进行陈述，从而确定快速共同适应的中心因素。

Modern agroecosystems are characterised by a low ecological diversity. This leads to a strong evolutionary selection pressure between interacting species like crop plants and their pests. Maize is one of the most widely cultivated crop species worldwide and a highly suitable model for the study of evolutionary processes in agroecosystems because of it high diversity of varieties and genomic variability. In a multi-year experiment, the co-evolution of maize and one of its most important pathogen, the fungus Exserohilum turcicum, will be investigated. This fungus causes Northern Leaf Blight and spreads throughout Central Europe. Two different maize varieties that differ in their resistance against the fungus will be inoculated and the most resistant plants will be selected. The fungi will be separated by the population and transferred into the next generation. This generates a strong selection pressure for co-adaptation between maize and pathogen population. In each of the three planned selection cycles, the maize and pathogen population will be genotyped and investigated with the methods of population genetics. The analysis is aimed at testing whether pathogen evolution differs in response to different host populations and which evolutionary model best describes the change of host and pathogen populations. By such a comparison, statements on the importance of genetic diversity in the crop and its pest for the coevolution can be made the central factors for a rapid co-adaptation can be identified.