目的 鉴定分别采于鄂尔多斯市巴彦淖尔碱湖的3种藻株,命名为sp.DD、sp.ER、sp.FB；采自哈素海的藻株，命名为sp.HS；获赠于中国海洋大学的藻株命名为sp.QD的5种藻株，并做系统发育分析。方法 将采集的藻液进行分离纯化，获得目的藻株，提取基因组DNA，PCR扩增ITS序列片段，进行序列测定和聚类分析。结果 系统发育分析表明，sp.HS 与 Arthrospira platensis strain Sp-2 在同一支上，同源性为 99.59%；sp.DD 单独一支，与 Arthrospira platensis“Inner Mongolia”的同源性为 88.01%；sp.QD 与 Arthrospira platensis F3S 在同一支上，同源性为 99.60%；sp.ER与 sp.FB 聚为一支，与 Arthrospira erdosensis“Inner Mongolia”同源性为 99.18%。结论 经鉴定 sp.HS、sp.DD、sp.QD 为 Arthrospira platensis，sp.ER与sp.FB为Arthrospira erdosensis，并揭示内蒙古鄂尔多斯地区节旋藻藻种间的系统发育关系。

Objective In an attempt to study taxonomic relationships among the five strains including three species from Bayannur alkaline lake in Ordos, named as sp.DD, sp.ER and sp.FB, one species from Hasu Sea in Hohhot named as sp.HS, and another species donated from the Ocean University of China, named as sp.QD. Methods The sampled algal liquid was isolated and purified to obtain the target algal strain, and then genome DNA was extracted. ITS sequence fragment was amplified for sequencing and cluster analysis. Results Phylogenetic analysis showed that sp.HS and Arthrospira platensis strain Sp-2 were on the samebranch, the homology similarity was 99.59%, sp.DD was on a single branch, the homology similarity with Arthrospira platensis"Inner Mongolia "was 88.01%, sp.QD and Arthrospira platensis F3S were on the same branch, the homology similarity was 99.60%, sp.ER and sp.FB were clustered into one branch, the homology similarity with Arthrospira erdosensis"Inner Mongolia"was 99.18% . Conclusions sp.HS,sp.DD and sp.QD were identified as Arthrospira platensis，sp.ER and sp.FB were identified as Arthrospira erdosensis.These findings revealed the phylogenetic relationship between Arthrospira species from Ordos in lnner Mongolia.

国家自然科学基金（32060217）；内蒙古自治区自然科学基金（2021MS08090）；内蒙古科技计划（2019GG160）；第“十一批”草原英才工程，内蒙古道地蒙药材免疫活性多糖制备及其构效关系研究创新人才团队；内蒙古医科大学“三位一体”大学生创新创业培育项目（SWYT2020035）