Genus richness of microalgae and Cyanobacteria in biological soil crusts from Svalbard and Livingston Island: morphological versus molecular approaches
Genus richness of microalgae and Cyanobacteria in biological soil crusts from Svalbard and Livingston Island: morphological versus molecular approaches
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DOI：
10.1007/s00300-018-2252-2
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发表时间：
2018-05-01
期刊：
影响因子：
1.7
通讯作者：
Becker, Burkhard
中科院分区：
文献类型：
--
作者：
Rippin, Martin;Borchhardt, Nadine;Becker, Burkhard
生物土壤结皮是极地生态系统的重要组成部分。这些复杂的群落对陆地极地生境很重要，因为它们包括固定氮、防止土壤侵蚀的主要初级生产者，并可被视为气候变化的指标。为了研究BSCs中微藻和蓝细菌的属丰富度，采用了两种不同的方法并比较了结果：使用光学显微镜进行形态学鉴定和从元转录组中提取的核糖体序列的注释。分析的样本采集自挪威斯瓦尔巴群岛的新奥勒松和南极洲利文斯顿岛的胡安·卡洛斯一世南极基地。本研究的重点是以下分类群：Klebsormidiophyceae，Chlorophyceae，Trebouxiophyceae，Xanthophyceae和Cyanobacteria。总的来说，结合这两种方法，分别在北极和南极样品中确定了143和103属。此外，这两种技术一致地确定了15个分类群在北极和7个分类群在南极BSC。在一般情况下，分子分析表明一个更高的微藻和蓝藻属丰富度（约11倍）比形态学的方法。在真核藻类方面，两个采样点显示出相当的属数，而蓝藻属丰富度高得多的BSC从新奥勒松。首次通过元转录组学分析确定了Chloroidium、Ankistrodesmus和Dunaliella属在极地的存在。总的来说，这些发现表明，与单一方法相比，只有形态学和分子技术的组合才能揭示复杂群落（如极地BSC）的属丰富度。
Biological soil crusts (BSCs) are key components of polar ecosystems. These complex communities are important for terrestrial polar habitats as they include major primary producers that fix nitrogen, prevent soil erosion and can be regarded as indicators for climate change. To study the genus richness of microalgae and Cyanobacteria in BSCs, two different methodologies were employed and the outcomes were compared: morphological identification using light microscopy and the annotation of ribosomal sequences taken from metatranscriptomes. The analyzed samples were collected from Ny-Alesund, Svalbard, Norway, and the Juan Carlos I Antarctic Base, Livingston Island, Antarctica. This study focused on the following taxonomic groups: Klebsormidiophyceae, Chlorophyceae, Trebouxiophyceae, Xanthophyceae and Cyanobacteria. In total, combining both approaches, 143 and 103 genera were identified in the Arctic and Antarctic samples, respectively. Furthermore, both techniques concordantly determined 15 taxa in the Arctic and 7 taxa in the Antarctic BSC. In general, the molecular analysis indicated a higher microalgal and cyanobacterial genus richness (about 11 times higher) than the morphological approach. In terms of eukaryotic algae, the two sampling sites displayed comparable genus counts while the cyanobacterial genus richness was much higher in the BSC from Ny-Alesund. For the first time, the presence of the genera Chloroidium, Ankistrodesmus and Dunaliella in polar regions was determined by the metatranscriptomic analysis. Overall, these findings illustrate that only the combination of morphological and molecular techniques, in contrast to one single approach, reveals higher genus richness for complex communities such as polar BSCs.