Institute of Eastern-Himalaya Biodiversity Research, Dali University, Hongsheng Rd. no. 2, Dali, 671003, Yunnan, China.
Collaborative Innovation Center for Biodiversity and Conservation in the Three Parallel, Rivers Region of China, Dali, 671003, Yunnan, China.
BMC Microbiol. 2024 Aug 15;24(1):305. doi: 10.1186/s12866-024-03451-w.
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.
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.
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.
系统发生地理学研究将过去的地质事件与生物多样性的分布模式联系起来，这一方法在多山地区尤为突出。然而，这些研究往往集中在植物分类群上，而忽略了微生物（特别是土壤微生物群落）复杂的生物地理格局。本文探讨了线虫诱捕真菌节丛孢（Arthrobotrys oligospora）在青藏高原东南缘构造活跃地区的空间分布。通过分析这种真菌的遗传变异与主要河流流域的历史结构，我们试图揭示两者之间可能存在的联系。我们的研究涉及从该地区六个主要流域的 116 个地点采集 149 株菌株。
产生的单倍型网络揭示了五个不同的聚类，每个聚类都与特定的流域密切对应。这些聚类表现出高单倍型多样性和低核苷酸多样性，支持基于流域的隔离假说。对跨流域共享单倍型的进一步分析提供了过去三条建议的河流连接的证据。特别是，我们在长江和湄公河流域之间以及长江和红河之间发现了许多共享的单倍型。我们的绘图练习还描绘了伊洛瓦底江-萨尔温江-红河以及长江-珍珠河之间的连接证据。
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方面的关键作用，以及当代生物和非生物因素的作用。流域边界成为这些模式的有效预测因子，表明它们适合作为区域尺度研究的分析单位。我们的研究还表明，微生物和系统地理学方法有潜力补充传统的地质分析，提供对过去景观结构及其演化的更全面理解。
