The Fusarium oxysporum species complex (FOSC) is a ubiquitous group of fungal species readily isolated from agroecosystem and natural ecosystem soils which includes important plant and human pathogens. Genetic relatedness within the complex has been studied by sequencing either the genes or the barcoding gene regions within those genes. Phylogenetic analyses have demonstrated a great deal of diversity which is reflected in the differing number of clades identified: three, five and eight. Genetic limitation within the species in the complex has been studied through Genealogical Concordance Phylogenetic Species Recognition (GCPSR) analyses with varying number of phylogenetic ‘species’ identified ranging from two to 21. Such differing views have continued to confuse users of these taxonomies. The phylogenetic relationships between Australian F. oxysporum isolates from both natural and agricultural ecosystems were determined using three datasets: whole genome, nuclear genes, and mitochondrial genome sequences. The phylogenies were concordant except for three isolates. There were three concordant clades from all the phylogenies suggesting similar evolutionary history for mitochondrial genome and nuclear genes for the isolates in these three clades. Applying a multispecies coalescent (MSC) model on the eight single copy nuclear protein coding genes from the nuclear gene dataset concluded that the three concordant clades correspond to three phylogenetic species within the FOSC. There was 100% posterior probability support for the formation of three species within the FOSC. This is the first report of using the MSC model to estimate species within the F. oxysporum species complex. The findings from this study were compared with previously published phylogenetics and species delimitation studies. Phylogenetic analyses using three different gene datasets from Australian F. oxysporum isolates have all supported the formation of three major clades which delineated into three species. Species 2 (Clade 3) may be called F. oxysporum as it contains the neotype for F. oxysporum.

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澳大利亚尖孢镰刀菌分离物与利用多物种合并模型解析物种复合体之间的亲缘关系

尖孢镰刀菌种复合物（FOSC）是一类无处不在的真菌种，很容易从农业生态系统和自然生态系统土壤中分离出来，土壤中包括重要的植物和人类病原体。通过对这些基因内的基因或条形码基因区域进行测序，研究了复合物中的遗传相关性。系统发育分析显示出很大的多样性，这反映在所鉴定的进化枝数目不同：三个，五个和八个。已通过遗传学共生系统发育物种识别（GCPSR）分析研究了该复合物中物种的遗传限制，其中鉴定出的系统发育“物种”数目从2到21不等。这种不同观点继续困扰着这些分类法的使用者。澳大利亚F之间的亲缘关系 使用三个数据集确定了来自自然生态系统和农业生态系统的芽孢分离株：全基因组，核基因和线粒体基因组序列。除了三个分离株外，系统发育一致。来自所有系统发育的三个一致进化枝表明这三个进化枝中线粒体基因组和核基因的相似进化史。在来自核基因数据集的八个单拷贝核蛋白编码基因上应用多物种合并（MSC）模型得出的结论是，三个一致进化枝对应于FOSC中的三个系统发育种。FOSC内三个物种的形成有100％的后验概率支持。这是使用MSC模型估算尖孢镰刀菌种复合体中物种的第一份报告。这项研究的结果与以前发表的系统发育和物种定界研究进行了比较。使用来自澳大利亚尖孢镰刀菌分离物的三个不同基因数据集进行的系统发育分析都支持形成三个主要进化枝的描述，该进化枝被分为三个物种。物种2（进化枝3）可以被称为尖孢镰刀菌，因为它含有尖孢镰刀菌的新型。