ABSTRACT The genus Hariotina was established in 1889 based on the type species Hariotina reticulata. This species was then transferred to Coelastrum by Senn (1899). The genus Hariotina was eventually restored by Hegewald et al. (2002) based on morphological characteristics. Species of Hariotina are ubiquitous in fresh water, especially in some tropical and subtropical areas. The taxonomic position of the genus is now considered to be within the family Scenedesmaceae. However, until now, there was an insufficient understanding of the molecular diversity within this genus, and the related reference sequences in the database were inadequate to resolve the species taxonomy. In this study, 20 strains of Hariotina were identified and successfully cultured in the laboratory. We used a combined approach, joining molecular and morphological analyses, to determine their taxonomic relationships and phylogenetic positions. The molecular analyses based on 18S rDNA+ITS sequences and the tufA gene resolved the analysed strains into at least six species, including the known species H. reticulata and H. polychorda and four new species herein described, i.e. H. hainanensis sp. nov., H. compacta sp. nov., H. guilinensis sp. nov. and H. laxa sp. nov. The genus Hariotina was confirmed in the Scenedesmaceae as a monophyletic clade that was closely related to the genus Coelastrum in tufA gene phylogeny. Strains with H. reticulata morphotype were found to be located on two different branches, and formed sister relationships with the other two morphologically distinct species. In addition, the topology was supported by all three DNA markers. The congruence between the phylogeny and the classical taxonomic system based on morphological criteria for this taxon is discussed.

中文翻译：

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Hariotina 属（Scenedesmaceae、Sphaeropleales）内的隐性物种，描述了该属的四个新物种

摘要 Hariotina 属成立于 1889 年，基于模式种 Hariotina reticulata。该物种随后被 Senn (1899) 转移到 Coelastrum。Hegewald 等人最终恢复了 Hariotina 属。(2002) 基于形态特征。Hariotina 的物种在淡水中无处不在，尤其是在一些热带和亚热带地区。该属的分类位置现在被认为属于栅栏科。然而，到目前为止，对该属内的分子多样性认识不足，数据库中的相关参考序列不足以解决物种分类问题。在这项研究中，鉴定出 20 株 Hariotina 并在实验室成功培养。我们使用了一种组合方法，结合分子和形态分析，以确定它们的分类关系和系统发育位置。基于 18S rDNA+ITS 序列和 tufA 基因的分子分析将所分析的菌株解析为至少六个物种，包括已知物种网状丝虫和多脊丝虫，以及本文所述的四个新物种，即 H. hainanensis sp.。十一月，H.compacta sp。nov., H. guilinensis sp. 十一月 和 H. laxa sp。十一月 Hariotina 属在 Scenedesmaceae 中被确认为单系进化枝，在 tufA 基因系统发育中与 Coelastrum 属密切相关。发现具有 H. reticulata 形态型的菌株位于两个不同的分支上，并与其他两个形态不同的物种形成姐妹关系。此外，所有三个 DNA 标记都支持该拓扑结构。