亚气生球状绿藻一新种——重庆单星藻  

COELASTRELLA CHONGQINGENSIS SP.NOV.,A NOVEL SPECIES OF THE SUBAERIAL COCCOID GREEN ALGAE WITHIN THE COELASTRELLA(SCENEDESMACEAE,SPHAEROPLEALES)

作　　者：王清华 宋会银 刘旭东 胡征宇[4] 刘国祥[4] WANG Qing-Hua;SONG Hui-Yin;LIU Xu-Dong;HU Zheng-Yu;LIU Guo-Xiang(Department of Biology,Taiyuan Normal University,Jinzhong 030619,China;CAS Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;School of Life Science,Shanxi University,Taiyuan 030006,China;Key Laboratory of Algal Biology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China)

机构地区：[1]太原师范学院生物系,晋中030619 [2]中国科学院海洋研究所海洋生态与环境科学重点实验室,青岛266071 [3]山西大学生命科学学院,太原030006 [4]中国科学院水生生物研究所中国科学院藻类生物学重点实验室,武汉430072

出　　处：《水生生物学报》2021年第6期1351-1360,共10页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(32000167和31900187);山西省应用基础研究计划青年科技研究基金(201901D211421和201901D211132);山西省高等学校科技创新项目(2020L0524和2019L0073);特色植物资源研究与利用山西省重点实验室开放项目;山西省“1331工程”重点创新团队建设基金和水污染生态修复重点实验室资助。

摘　　要：单星藻隶属于绿藻纲环藻目栅藻科,多为单细胞或聚合群体,属内已知种类多发现于气生、亚气生生境,在天然抗氧化剂和食品色素生产等领域具有广阔应用前景。但目前关于该类群的基础分类学研究相对薄弱,阻碍了这些优质藻种资源的进一步开发利用。本研究从重庆市及周口市采集到2株单星藻,经形态学及18S rDNA、ITS和tufA三个分子标记鉴定为单星藻属一新种,命名为重庆单星藻Coelastrella chongqingensis sp.nov.。重庆单星藻显著的形态特征是细胞壁近似光滑或仅具细微皱纹,不具有典型单星藻类群纵向分布的肋纹,幼期细胞多呈椭球形或卵形,末端钝圆,细胞大小约(6-9)μm×(5-7)μm。成熟细胞多呈圆球形或椭球形,直径约8-14-(18)μm。系统发育分析结果显示重庆单星藻与另外2种细胞壁近似光滑的藻株液泡单星藻Coelastrella vacuolata和薄壁单星藻Coelastrella tenuitheca具有最近的亲缘关系,三者在基于tufA序列的系统发育分析中形成独立单系分支,代表单星藻属第三种形态型,即细胞壁近似光滑或仅具细微网纹,无单星藻属典型的纵向肋纹。新种的发现扩充了单星藻属第三种形态型的物种组成,为该属进一步的分类学修订打下基础。The genus Coelastrella was taxonomically positioned in the family Scenedesmaceae(Sphaeropleales,Chlorophyceae),and was characterized as unicellular or few-celled aggregations.Species within the genus are mostly found in aerial and sub-aerial habitats,which are different from other freshwater-living members of Scenedesmaceae.They have good tolerance to some stress conditions,such as high temperature,high salt,and ultraviolet.The most notable feature of the genus Coelastrella is that the cells tend to accumulate carotenoids and oils in the late growth stage,or under some stress conditions such as nitrogen deficiency and high salt.This group has been proved to have broad application prospects in the fields of natural antioxidants and food pigment production.In this study,two strains of the genus Coelastrella were collected from Chongqing and Xinyang,and they were identified as a new species of the genus Coelastrella by morphology and three molecular markers of 18S rDNA,ITS,and tufA gene.The remarkable morphological feature of Coelastrella chongqingensis is that the cell wall is approximately smooth or only slightly wrinkled,without the meridianal ribs of the typical Coelastrella species.The young cells are mostly ellipsoidal or oval with obtuse ends with a size of(0-9)μm×(5-7)μm.The mature cells are mostly spherical or ellipsoidal with a size of 8-14-(18)μm.The results of the phylogenetic analysis showed that Coelastrella chongqingensis was closely related to Coelastrella vacuolata and Coelastrella tenuitheca.They all have similar morphotype,and formed independent monophyletic group in the phylogeny of tufA gene.This branch represents the third morphotype of Coelastrella,that is,the cell wall is approximately smooth or with a network of fine ribs without the typical meridional ribs of Coelastrella.

关 键 词：单星藻属 重庆单星藻 栅藻科 形态学 系统发育 新种 

分 类 号：Q949.21[生物学—植物学]