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，在养分循环中起着重要作用。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作和持续。特别是，我们需要了解EMF是如何扩散、在新栖息地定居、持续存在、适应宿主并在更长期内形成物种的。施泰因皮尔兹（Boletus edulis）可以说是最重要的商业收获野生蘑菇。它具有广泛的地理分布，并与几种树种有专门的菌根联系，这就提出了一个问题，即本地适应是否发生在当地占优势的宿主身上。B. edulis也倾向于在当地丰富，允许随着时间的推移对孢子囊进行系统采样。该项目将利用大量的双歧杆菌样本来提供最全面的野生真菌种群基因组研究。全基因组重测序和最先进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，对德国比勒费尔德（Bielefeld）和英国塞特福德森林/巴纳姆（Thetford Forest / Barnham）的多个林地斑块进行系统的重复采样，追踪个体少于11年的时间，并重建基因更替和当地扩散的模式。虽然我们的取样主要集中在子果皮上，但根尖的ITS基因分型也将用于确认毛蕊双歧杆菌的存在/不存在。个体的观察历史将用于检验基因寿命与基因型有关的假设，选择倾向于特定的等位基因或更多的杂合基因型。我们还将研究对特定寄主树的局部适应导致传播和/或寿命偏差模式的可能性。其次，我们将通过收集来自四个地区（比勒菲尔德、塞特福德/巴纳姆、西班牙和瑞典）的四种寄主树（山毛榉、橡树、桦树和松树）的孢子果，研究寄主专业化是否可能是生态物种形成的一条途径。这将使我们能够测试宿主相关基因是否代表部分生殖隔离的宿主种族，如果是这样，就可以确定参与早期物种形成的基因组区域。重复采样将允许我们确认因果关系，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，并将干燥的孢子囊保存在森肯堡自然历史博物馆的真菌馆里，网址是Görlitz。总体而言，该项目将提供迄今为止有关EMF种群如何建立、传播和演变的前所未有的详细图像。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，为未来市场上的微生物研究提供参考。

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.