Genomic analysis of dispersal and adaptation in Steinpilz mushrooms

外生菌根真菌(EMF)是陆地生态系统的重要组成部分，在养分循环中起着至关重要的作用。迫切需要研究它们的种群动态和生活史，以便更好地了解生态系统如何运行和持续存在。特别是，我们需要了解电磁场是如何分散、殖民新的栖息地、持续存在、适应宿主和长期物种的。甜菇可以说是最重要的商业收获的野生蘑菇。它具有广泛的地理分布，并与几个树种有专有的菌根联系，这引发了一个问题，即局部适应是否发生在局部占优势的宿主上。美味假单胞菌在当地往往也很丰富，允许随着时间的推移对孢子果进行系统采样。该项目将利用大量的美味假单胞菌样本来提供可以说是所有野生真菌中最全面的种群基因组研究。全基因组重测序和最新的种群基因组方法将用于阐明生态和进化时间尺度上的关键过程。首先，将使用来自德国比勒费尔德和英国塞特福德森林/巴纳姆的多个林地斑块的系统重复采样来跟踪个体长达11年的时间，并重建基因周转和局部扩散的模式。虽然我们的采样主要集中在孢子果上，但其根尖的基因分型也将用于确认是否存在美味球孢菌。我们将利用个体视力史来检验这样一种假设，即基因寿命与基因类型有关，选择倾向于特定的等位基因或更杂合的基因类型。其次，我们将通过从四个地区(比勒费尔德、塞特福德/巴纳姆、西班牙和瑞典)收集与四种寄主树木(山毛榉、橡树、桦树和松树)相关的孢子果，来研究寄主专业化是否可能是一种生态物种形成的途径。这将使我们能够测试与宿主相关的基因组是否代表部分繁殖隔离的宿主小种，如果是的话，则识别参与早期物种形成的基因组区域。重复抽样将使我们能够确认因果关系，同时排除当地的候选因素，如气候、与其他真菌的相互作用或非生物因素。我们还将使用DNA条形码来验证寄主关联，并将干燥的孢子果保存在格利茨森肯堡自然历史博物馆的真菌馆中。总体而言，这个项目将产生一幅迄今为止前所未有的详细图片，展示EMF种群如何建立、传播和进化。了解这些过程对于预测生态系统对气候变化的反应至关重要。该项目还将产生分子资源和模式标本，用于未来对商品化牛肝菌的研究。

Ectomycorrhizal fungi (EMF) are critical components of terrestrial ecosystems that play essential roles in nutrient recycling. There is a pressing need to study their population dynamics and life histories so as to better understand how ecosystems function and persist. In particular, we need to learn how EMF disperse, colonise new habitats, persist, adapt to their hosts and in the longer term speciate.The Steinpilz (Boletus edulis) is arguably the most important commercially harvested wild mushroom. It has a broad geographic distribution and has obligate mycorrhizal associations with several tree species, raising questions about whether local adaptation occurs to whichever host is locally dominant. B. edulis also tends to be locally abundant, allowing the systematic sampling of sporocarps through time.This project will exploit a large collection of B. edulis samples to deliver arguably the most comprehensive population genomic study of any wild fungus. Whole genome resequencing and state of the art population genomic approaches will be used to elucidate key processes on both ecological and evolutionary timescales.First, systematic repeated sampling of multiple woodland patches from Bielefeld (Germany) and Thetford Forest / Barnham (UK) will be used to track individuals over <11 years and to reconstruct patterns of genet turnover and local dispersal. While our sampling focuses mainly on sporocarps, ITS genotyping of root tips will also be used to confirm the presence / absence of B. edulis. Individual sighting histories will be used to test the hypothesis that genet longevity is related to genotype, with selection favouring either specific alleles or more heterozygous genotypes. We will also investigate the possibility that local adaptation to specific host trees results in biased patterns of dispersal and / or longevity.Second, we will investigate whether host specialization may be a route to ecological speciation by collecting sporocarps associated with four host trees (beech, oak, birch and pine) from four localities (Bielefeld, Thetford / Barnham, Spain and Sweden). This will allow us to test whether host-associated genets represent partially reproductively isolated host races, and if so, to identify genomic regions involved in early speciation. Replicated sampling will allow us to confirm causal relationships while excluding local candidate factors such as climate, interactions with other fungi, or abiotic factors. We will also use DNA barcoding to verify host associations and archive the dried sporocarps at the fungarium of the Senckenberg Museum of Natural History, Görlitz.Overall, this project will produce an unprecedentedly detailed picture to date of how EMF populations become established, spread and evolve. Understanding these processes is essential for predicting ecosystem responses to climate change. This project will also generate molecular resources and type specimens for future research on marketable boletes.