Five cyanobacterial strains exhibiting Nostoc-like morphology were sampled from the biodiversity hotspots of the northeast region of India and characterized using a polyphasic approach. Molecular and phylogenetic analysis using the 16S rRNA gene indicated that the strains belonged to the genera Amazonocrinis and Dendronalium. In the present investigation, the 16S rRNA gene phylogeny clearly demarcated two separate clades of Amazonocrinis. The strain MEG8-PS clustered along with Amazonocrinis nigriterrae CENA67, which is the type strain of the genus. The other three strains ASM11-PS, RAN-4C-PS, and NP-KLS-5A-PS clustered in a different clade that was phylogenetically distinct from the Amazonocrinis sensu stricto clade. Interestingly, while the 16S rRNA gene phylogeny exhibited two separate clusters, the 16S–23S ITS region analysis did not provide strong support for the phylogenetic observation. Subsequent analyses raised questions regarding the resolving power of the 16S–23S ITS region at the genera level and the associated complexities in cyanobacterial taxonomy. Through this study, we describe a novel genus Ahomia to accommodate the members clustering outside the Amazonocrinis sensu stricto clade. In addition, we describe five novel species, Ahomia kamrupensis, Ahomia purpurea, Ahomia soli, Amazonocrinis meghalayensis, and Dendronalium spirale, in accordance with the International Code of Nomenclature for algae, fungi, and plants (ICN). Apart from further enriching the genera Amazonocrinis and Dendronalium, the current study helps to resolve the taxonomic complexities revolving around the genus Amazonocrinis and aims to attract researchers to the continued exploration of the tropical and subtropical cyanobacteria for interesting taxa and lineages.

中文翻译：

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激发分类学好奇心：Amazonocrinis 的惊人故事以及新属 Ahomia gen 的描述。十一月以及来自生物多样性丰富的印度东北部地区的 Ahomia、Amazonocrinis 和 Dendronalium 等新物种

从印度东北地区的生物多样性热点地区采集了五种表现出发菜样形态的蓝藻菌株，并使用多相方法进行了表征。使用 16S rRNA 基因进行的分子和系统发育分析表明，这些菌株属于Amazonocrinis属和Dendronalium属。在本研究中，16S rRNA 基因系统发育清楚地划分了Amazonocrinis的两个独立分支。 MEG8-PS 菌株与该属的模式菌株Amazonocrinis nigriterrae CENA67 聚集在一起。其他三个菌株 ASM11-PS、RAN-4C-PS 和 NP-KLS-5A-PS 聚集在一个不同的分支中，该分支在系统发育上与Amazonocrinis sensu stricto 分支不同。有趣的是，虽然16S rRNA基因系统发育表现出两个独立的簇，但16S-23S ITS区域分析并没有为系统发育观察提供强有力的支持。随后的分析提出了有关 16S-23S ITS 区域在属水平上的分辨能力以及蓝藻分类学中相关复杂性的问题。通过这项研究，我们描述了一个新的Ahomia属，以容纳聚集在Amazonocrinis sensu stricto clade之外的成员。此外，我们根据国际藻类、真菌和植物命名法 (ICN)描述了五个新物种： Ahomia kamrupensis、Ahomia purpurea、Ahomia soli、Amazonocrinis meghalayensis和Dendronaliumspirale 。除了进一步丰富Amazonocrinis属和Dendronalium属之外，当前的研究还有助于解决围绕Amazonocrinis属的分类学复杂性，并旨在吸引研究人员继续探索热带和亚热带蓝藻以寻找有趣的分类群和谱系。