Chloromonas svalbardensis n. sp with Insights into the Phylogroup Chloromonadinia (Chlorophyceae)
Chloromonas svalbardensis n. sp with Insights into the Phylogroup Chloromonadinia (Chlorophyceae)
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DOI：
10.1111/jeu.12633
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发表时间：
2018-11-01
影响因子：
2.2
通讯作者：
Elster, Josef
中科院分区：
文献类型：
--
作者：
Barcyte, Dovile;Hodac, Ladislav;Elster, Josef
传统的绿色藻属绿单胞菌（Chloromonas）包括嗜温、耐寒和适冷的微生物。本文研究了一个从高北极地区潮湿的丘陵草甸中分离到的新菌株。我们使用形态学，超微结构和分子数据来评估新分离物的分类位置和系统发育关系。观察到的形态特征一般对应于耐寒的绿单胞菌的特性。然而，椭圆形或宽椭圆形的营养细胞，一个巨大的壁杯状叶绿体与一些连续连接的裂片，厚的细胞壁，一个突出的半球形乳头和一个椭圆形或圆形的眼点的前面的位置区分所有以前描述的绿单胞菌属物种。rbcL和18 S rRNA基因的分析表明，新菌株形成了一个独立的谱系内含有嗜温和耐冷的氯单胞菌物种的分支。一个高度可变的ITS 2 rDNA标记的二级结构模型的比较支持一个单独的物种身份的新分离物。考虑到与其近缘种在形态和分子上的差异，提出了一个新的耐冷菌种--斯瓦尔巴绿单胞菌（Chloromonasvalbardensis）。此外，我们的研究结果表明，并系起源的绿单胞菌属内的遗传，形态和生态明确的分支。我们讨论了一个可能的绿单胞菌分裂和修订的情况。
The traditional green algal genus Chloromonas accommodates mesophilic, cold-tolerant and cold-adapted microorganisms. In this paper, we studied a new strain isolated from a wet hummock meadow in the High Arctic. We used morphological, ultrastructural and molecular data to assess the taxonomic position and phylogenetic relationships of the new isolate. The observed morphological features generally corresponded to the cold-tolerant Chloromonas characteristics. However, ellipsoidal or wide ellipsoidal vegetative cells, a massive parietal cup-shaped chloroplast with a number of continuously connected lobes, a thick cell wall, a prominent hemispherical papilla and the anterior position of an oblong or round eyespot distinguished the alga from all previously described Chloromonas species. Analyses of rbcL and 18S rRNA genes showed that the new strain formed an independent lineage within a clade containing mesophilic and psychrotolerant Chloromonas species. Comparisons of secondary structure models of a highly variable ITS2 rDNA marker supported a separate species identity of the new isolate. Considering the morphological and molecular differences from its relatives, a new psychrotolerant species, Chloromonas svalbardensis, is proposed. Further, our results demonstrated the paraphyletic origin of Chloromonas within Chloromonadinia with genetically, morphologically and ecologically well-defined clades. We discuss a scenario of a possible Chloromonas split and revision.