Species delimitation in fungal endophyte diversity studies and its implications in ecological and biogeographic inferences
Species delimitation in fungal endophyte diversity studies and its implications in ecological and biogeographic inferences
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DOI：
10.1111/j.1365-294x.2011.05110.x
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发表时间：
2011-07-01
影响因子：
4.9
通讯作者：
Chaverri, Priscila
中科院分区：
文献类型：
--
作者：
Gazis, Romina;Rehner, Stephen;Chaverri, Priscila
内生真菌群落物种多样性的估计是基于物种计数或操作分类单位（OTU）的分配。因此，不同物种识别标准的应用不仅影响多样性估计，而且影响从这些观察中产生的生态假设。这项研究的主要目的是审查遗传标记的选择和数量以及物种划界标准如何影响生物多样性估计数。在这里，我们比较了热带内生菌的三个优势种复合体，特别是胶孢炭疽菌，小孢拟盘多毛孢菌和哈茨木霉，巴西橡胶树（Hevea brasiliensis）和巴西橡胶树（H.圭亚那。分子工具被用来描述和比较不同组合的多样性。多位点系统发育分析[gpd，内部转录间隔区（ITS）和tef1]和现代技术的系统发育物种划界与生态数据重叠，以识别推定的物种或OTU。结果表明，ITS单独一般低估了其他核位点预测的物种数。这些结果质疑使用ITS和任意分歧阈值的物种划界。
The estimation of species diversity in fungal endophyte communities is based either on species counts or on the assignment of operational taxonomic units (OTUs). Consequently, the application of different species recognition criteria affects not only diversity estimates but also the ecological hypotheses that arise from those observations. The main objective of the study was to examine how the choice and number of genetic markers and species delimitation criteria influence biodiversity estimates. Here, we compare approaches to defining species boundaries in three dominant species complexes of tropical endophytes, specially Colletotrichum gloeosporioides agg., Pestalotiopsis microspora agg. and Trichoderma harzianum agg., from two Amazonian trees: Hevea brasiliensis and H. guianensis. Molecular tools were used to describe and compare the diversity of the different assemblages. Multilocus phylogenetic analyses [gpd, internal transcribed spacer (ITS) and tef1] and modern techniques for phylogenetic species delimitation were overlaid with ecological data to recognize putative species or OTUs. The results demonstrate that ITS alone generally underestimates the number of species predicted by other nuclear loci. These results question the use of ITS and arbitrary divergence thresholds for species delimitation.