Terrestrial, freshwater and marine green algae constitute the large and morphologically diverse phylum of Chlorophyta, which gave rise to the core chlorophytes. Chlorophyta are abundant and diverse in freshwater environments where sometimes they form nuisance blooms under eutrophication conditions. The phylogenetic relationships among core chlorophyte clades (Chlorodendrophyceae, Ulvophyceae, Trebouxiophyceae and Chlorophyceae), are of particular interest as it is a species-rich phylum with ecological importance worldwide, but are still poorly understood. In the Mediterranean ecoregion, data on molecular characterization of eukaryotic microalgae strains are limited and current knowledge is based on ecological studies of natural populations. In the present study we report the isolation and characterization of 11 green microalgae strains from Greece contributing more information for the taxonomy of Chlorophyta. The study combined morphological and molecular data. Phylogenetic analysis based on 18S rRNA, internal transcribed spacer (ITS) region and the large subunit of the ribulose-bisphosphate carboxylase (rbcL) gene revealed eight taxa. Eleven green algae strains were classified in four orders (Sphaeropleales, Chlorellales, Chlamydomonadales and Chaetophorales) and were represented by four genera; one strain was not assigned to any genus. Most strains (six) were classified to the genus Desmodesmus, two strains to genus Chlorella, one to genus Spongiosarcinopsis and one filamentous strain to genus Uronema. One strain is placed in a separate independent branch within the Chlamydomonadales and deserves further research. Our study reports, for the first time, the presence of Uronema in an aquatic environment up to 40 °C and reveals new diversity within the Chlamydomonadales. The results from the ITS region and the rbcL gene corroborated those obtained from 18S rRNA without providing further information or resolving the phylogenetic relationships within certain genera, due to the limited number of ITS and rbcL sequences available. The comparison of molecular and morphological data showed that they were congruent. Cosmopolitan genera with high worldwide distribution inhabit Greek freshwaters.

中文翻译：

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从地中海淡水分离出的绿藻菌株的多相分类学

陆地，淡水和海洋绿藻构成了绿藻门的大型且形态多样的门，从而形成了核心的叶绿素。绿藻在淡水环境中丰富多样，有时在富营养化条件下会形成讨厌的花朵。核心绿化植物进化枝之间的系统发育关系特别引起人们的兴趣，因为它是一种物种丰富的植物，在世界范围内具有重要的生态意义，但人们对此知之甚少。在地中海生态区，有关真核微藻菌株的分子表征的数据有限，目前的知识是基于对自然种群的生态研究。在本研究中，我们报告了来自希腊的11种绿色微藻菌株的分离和表征，为绿藻的分类学提供了更多信息。该研究结合了形态学和分子数据。基于18S rRNA，内部转录间隔区（ITS）区域和核糖二磷酸羧化酶（r​​bcL）基因的大亚基的系统发育分析揭示了八类。将11个绿藻菌株分为四个等级（球形藻，小球藻，衣藻和Chaetophorales），并以四个属为代表。一个菌株未分配给任何属。大多数菌株（六种）被归类为Desmodesmus属，两类归为小球藻属，一类归为海绵状孢菌属，一类丝状菌归为Uronema属。一种菌株被放置在衣藻的一个独立的独立分支中，值得进一步研究。我们的研究首次报道了在高达40°C的水生环境中存在Uronema，并揭示了衣藻的新多样性。由于可用的ITS和rbcL序列数量有限，ITS区和rbcL基因的结果证实了从18S rRNA获得的结果，而没有提供进一步的信息或解决某些属内的系统发育关系。分子和形态数据的比较表明它们是一致的。大都会属在全球范围内分布于希腊淡水中。在最高40°C的水生环境中存在Uronema，并揭示了衣藻的新多样性。由于可用的ITS和rbcL序列数量有限，ITS区和rbcL基因的结果证实了从18S rRNA获得的结果，而没有提供进一步的信息或解决某些属内的系统发育关系。分子和形态数据的比较表明它们是一致的。大都会属在全球范围内分布于希腊淡水中。在高达40°C的水生环境中存在Uronema，并揭示了衣藻的新多样性。由于可用的ITS和rbcL序列数量有限，ITS区和rbcL基因的结果证实了从18S rRNA获得的结果，而没有提供进一步的信息或解决某些属内的系统发育关系。分子和形态数据的比较表明它们是一致的。大都会属在全球范围内分布于希腊淡水中。分子和形态数据的比较表明它们是一致的。大都会属在全球范围内分布于希腊淡水中。分子和形态数据的比较表明它们是一致的。大都会属在全球范围内分布于希腊淡水中。