In order to understand Chamaesiphon spp. evolution and ecological diversification, we investigated the phylogenetic differentiation of three morphospecies from field samples by means of single colony genetics. Individual colonies of three different morphospecies (C. starmachii, C. polonicus, C. geitleri,) were isolated from lotic gravel streams and their 16S rDNA nucleotide variability was analyzed. For a number of individual colonies, microscopical and ultrastructural analysis was also performed. A phylogenetic tree of all major lineages of the phylum of Cyanobacteria assigned all Chamaesiphon genotypes (1149–1176 bp) most closely with the family of Gomontiellaceae of the order Oscillatoriales. The sequences obtained from colonies assigned to C. starmachii (n = 21), C. polonicus (n = 9), and C. geitleri (n = 17) were found to reveal high average (3.5%) nucleotide diversity. No phylogenetic sub-branching in correspondence with morphology was observed suggesting that the three Chamaesiphon morphospecies did not represent monophyletic taxa. We could not attribute specific thylakoid ultrastructure to phylogenetic sub-branches; however, the observed parietally and loosely arranged thylakoids indicate that for the genus Chamaesiphon, the variability in thylakoid ultrastructure might have been underestimated. In summary, the high nucleotide diversity of the 16S rDNA gene implies phylogenetic diversity that corresponds little to morphological classification.

中文翻译：

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Chamaesiphon spp 属上石流藻的单菌落遗传分析。

为了了解 Chamaesiphon spp。进化和生态多样化，我们通过单菌落遗传学研究了田间样本中三种形态物种的系统发育分化。三种不同形态物种（C. starmachii、C. polonicus、C. geitleri）的单个菌落从洗砾石流中分离出来，并分析了它们的 16S rDNA 核苷酸变异性。对于许多单个菌落，还进行了显微镜和超微结构分析。蓝藻门所有主要谱系的系统发育树将所有 Chamaesiphon 基因型 (1149-1176 bp) 分配给与 Oscillatoriales 目 Gomontiellaceae 家族最接近的。从分配给 C. starmachii (n = 21)、C. polonicus (n = 9) 和 C. geitleri (n = 17) 被发现显示高平均 (3.5%) 核苷酸多样性。没有观察到与形态相对应的系统发育亚分支，这表明三种 Chamaesiphon 形态种不代表单系分类群。我们不能将特定的类囊体超微结构归因于系统发育亚支；然而，观察到的顶叶和松散排列的类囊体表明，对于 Chamaesiphon 属，类囊体超微结构的变异性可能被低估了。总之，16S rDNA 基因的高核苷酸多样性意味着系统发育多样性与形态分类几乎没有对应关系。没有观察到与形态相对应的系统发育亚分支，这表明三种 Chamaesiphon 形态种不代表单系分类群。我们不能将特定的类囊体超微结构归因于系统发育亚支；然而，观察到的顶叶和松散排列的类囊体表明，对于 Chamaesiphon 属，类囊体超微结构的变异性可能被低估了。总之，16S rDNA 基因的高核苷酸多样性意味着系统发育多样性与形态分类几乎没有对应关系。没有观察到与形态相对应的系统发育亚分支，这表明三种 Chamaesiphon 形态种不代表单系分类群。我们不能将特定的类囊体超微结构归因于系统发育亚支；然而，观察到的顶叶和松散排列的类囊体表明，对于 Chamaesiphon 属，类囊体超微结构的变异性可能被低估了。总之，16S rDNA 基因的高核苷酸多样性意味着系统发育多样性与形态分类几乎没有对应关系。类囊体超微结构的变异性可能被低估了。总之，16S rDNA 基因的高核苷酸多样性意味着系统发育多样性与形态分类几乎没有对应关系。类囊体超微结构的变异性可能被低估了。总之，16S rDNA 基因的高核苷酸多样性意味着系统发育多样性与形态分类几乎没有对应关系。