东海多环旋沟藻的形态特征和系统进化分析

摘要

A dinoflagellate strain Cochlodinium polykrikoides Margalef (LAMB110745) was isolated from the East China Sea and the taxonomy reported first time in China.The strain is described in morphology using light microscope,fluorescence microscope,and scanning electron microscope,and in phylogeny using partial analysis for the large subunit ribosomal RNA gene (LSU rDNA).The results show that the cells are 26-35μm long and 15-22μm wide.The C.polykrikoides strain was shown as a single cell or chainlike cells.The number of cells in chain could be 2,4,8,and even 16.The cingulum is highly concave and encircles a cell nearly twice.The flagellate is intertwined in the cingulum.The sulcus runs closely down just below the cingulum.The nucleus is large and located at the anterior of the epicone.There are many chloroplasts distributed within cells and they are rod-like in shape.The LSU rDNA D1-D3 sequences is 870bp long.The phylogenetic tree and pairwise distances of Jukes-Cantor were acquired based on the D1-D3 sequences,indicating that the strain LAMB 110745 is of the East Asian ribotype.%本文首次对分离自我国东海海域的多环旋沟藻(Cochlodinium polykrikoides Margalef)藻株进行了详细的分类学报道.通过运用光学显微镜、荧光显微镜、电子扫描电镜和分子生物学方法,对多环旋沟藻的形态和显微特征进行了详细的描述,并对其核糖体大亚基序列(LSU rDNA)进行了系统进化分析.该藻以单细胞或链状细胞形态存在.通常链状包括2、4、8和16个细胞.横沟宽且深围绕细胞近2圈,内含鞭毛.纵沟窄并浅紧挨着横沟延伸.具有U形顶沟,细胞核大而圆,分布在上锥的前端.叶绿体棒状,数量较多并呈簇状分布.测序获得核糖体大亚基D 1-D3区序列为870bp,通过构建系统发育树和Jukes-Cantor遗传距离矩阵可知东海多环旋沟藻藻株为东亚型.