Oono Ryoko, Rasmussen Anna, Lefèvre Emilie
Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106, USA.
Department of Civil and Environmental Engineering, Duke University, Durham, NC, 27708, USA.
Environ Microbiol. 2017 Jul;19(7):2794-2805. doi: 10.1111/1462-2920.13799. Epub 2017 Jun 22.
Foliar fungal endophytes represent a diverse and species-rich plant microbiome. Their biogeography provides essential clues to their cryptic relationship with hosts and the environment in which they disperse. We present species composition, diversity, and dispersal patterns of endophytic fungi associated with needles of Pinus taeda trees across regional scales in the absence of strong environmental gradients as well as within individual trees. An empirical designation of rare and abundant taxa enlightens us on the structure of endophyte communities. We report multiple distance-decay patterns consistent with effects of dispersal limitation, largely driven by community changes in rare taxa, those taxonomic units that made up less than 0.31% of reads per sample on average. Distance-decay rates and community structure also depended on specific classes of fungi and were predominantly influenced by rare members of Dothideomycetes. Communities separated by urban areas also revealed stronger effects of distance on community similarity, confirming that host density and diversity plays an important role in symbiont biogeography, which may ultimately lead to a mosaic of functional diversity as well as rare species diversity across landscapes.
叶部真菌内生菌代表了一个多样且物种丰富的植物微生物群落。它们的生物地理学为其与宿主以及它们所散布的环境之间的隐秘关系提供了重要线索。我们展示了在没有强烈环境梯度的区域尺度以及单株树木内，与火炬松针叶相关的内生真菌的物种组成、多样性和散布模式。对稀有和丰富分类单元的实证界定让我们了解了内生菌群落的结构。我们报告了多种与扩散限制效应一致的距离衰减模式，这主要由稀有分类单元的群落变化驱动，这些分类单元平均占每个样本读数的比例不到0.31%。距离衰减率和群落结构也取决于特定的真菌类别，并且主要受座囊菌纲稀有成员的影响。被城市区域分隔的群落也显示出距离对群落相似性的更强影响，证实宿主密度和多样性在共生生物地理学中起着重要作用，这最终可能导致整个景观中功能多样性以及稀有物种多样性的镶嵌分布。
