PDF(Pubmed)
Abstract：
BACKGROUND: Phylogeographic studies have gained prominence in linking past geological events to the distribution patterns of biodiversity, primarily in mountainous regions. However, such studies often focus on plant taxa, neglecting the intricate biogeographical patterns of microbes, particularly soil microbial communities. This article explores the spatial distribution of the nematode-trapping fungus Arthrobotrys oligospora, a widespread microorganism, in a tectonically active region at the southeastern edge of the Qinghai-Tibetan Plateau. By analysing the genetic variation of this fungus alongside the historical structure of major river watersheds, we sought to uncover potential connections between the two. Our study involved sampling 149 strains from 116 sites across six major watersheds in the region.
RESULTS: The resulting haplotype network revealed five distinct clusters, each corresponding closely to a specific watershed. These clusters exhibited high haplotype diversity and low nucleotide diversity, supporting the notion of watershed-based segregation. Further analysis of haplotypes shared across watersheds provided evidence for three proposed past river connections. In particular, we found numerous shared haplotypes between the Yangtze and Mekong basins, as well as between the Yangtze and the Red basins. Evidence for a Irrawaddy-Salween-Red and a Yangtze-Pearl-Red river connections were also portrayed in our mapping exercise.
CONCLUSIONS: These findings emphasize the crucial role of historical geomorphological events in shaping the biogeography of microbial biodiversity, alongside contemporary biotic and abiotic factors. Watershed perimeters emerged as effective predictors of such patterns, suggesting their suitability as analytical units for regional-scale studies. Our study also demonstrates the potential of microorganisms and phylogeographic approaches to complement traditional geological analyses, providing a more comprehensive understanding of past landscape structure and its evolution.
RESULTS: The resulting haplotype network revealed five distinct clusters, each corresponding closely to a specific watershed. These clusters exhibited high haplotype diversity and low nucleotide diversity, supporting the notion of watershed-based segregation. Further analysis of haplotypes shared across watersheds provided evidence for three proposed past river connections. In particular, we found numerous shared haplotypes between the Yangtze and Mekong basins, as well as between the Yangtze and the Red basins. Evidence for a Irrawaddy-Salween-Red and a Yangtze-Pearl-Red river connections were also portrayed in our mapping exercise.
CONCLUSIONS: These findings emphasize the crucial role of historical geomorphological events in shaping the biogeography of microbial biodiversity, alongside contemporary biotic and abiotic factors. Watershed perimeters emerged as effective predictors of such patterns, suggesting their suitability as analytical units for regional-scale studies. Our study also demonstrates the potential of microorganisms and phylogeographic approaches to complement traditional geological analyses, providing a more comprehensive understanding of past landscape structure and its evolution.
摘要：
背景：在将过去的地质事件与生物多样性的分布模式联系起来方面，系统地理学研究已经越来越突出。主要在山区。然而,这些研究通常集中在植物类群上，忽略了微生物复杂的生物地理模式，特别是土壤微生物群落。本文探讨了线虫诱捕真菌Arthrobotrys寡孢子的空间分布，一种广泛存在的微生物，在青藏高原东南边缘的构造活跃地区。通过分析这种真菌的遗传变异以及主要河流流域的历史结构，我们试图发现两者之间的潜在联系。我们的研究涉及从该地区六个主要流域的116个地点采样149个菌株。
结果：得到的单倍型网络揭示了五个不同的簇，每个都与特定的分水岭紧密对应。这些簇表现出高的单倍型多样性和低的核苷酸多样性，支持基于分水岭的隔离概念。对流域共享的单倍型的进一步分析为过去提出的三个河流连接提供了证据。特别是,我们在长江和湄公河流域之间发现了许多共享的单倍型，以及长江和红盆之间。在我们的制图工作中还描绘了伊洛瓦底江-萨尔温江-红河和长江-珍珠-红河连接的证据。
结论：这些发现强调了历史地貌事件在塑造微生物生物多样性的生物地理学中的关键作用，以及当代生物和非生物因素。分水岭周边成为这种模式的有效预测因子，表明它们适合作为区域规模研究的分析单位。我们的研究还证明了微生物和系统地理学方法补充传统地质分析的潜力，更全面地了解过去的景观结构及其演变。
结果：得到的单倍型网络揭示了五个不同的簇，每个都与特定的分水岭紧密对应。这些簇表现出高的单倍型多样性和低的核苷酸多样性，支持基于分水岭的隔离概念。对流域共享的单倍型的进一步分析为过去提出的三个河流连接提供了证据。特别是,我们在长江和湄公河流域之间发现了许多共享的单倍型，以及长江和红盆之间。在我们的制图工作中还描绘了伊洛瓦底江-萨尔温江-红河和长江-珍珠-红河连接的证据。
结论：这些发现强调了历史地貌事件在塑造微生物生物多样性的生物地理学中的关键作用，以及当代生物和非生物因素。分水岭周边成为这种模式的有效预测因子，表明它们适合作为区域规模研究的分析单位。我们的研究还证明了微生物和系统地理学方法补充传统地质分析的潜力，更全面地了解过去的景观结构及其演变。
