东海三叶原甲藻(Prorocentrum triestinum)的形态特征及其ITS序列分析

Morphological characteristic and ITS sequence analysis of Prorocentrum triestinum isolated from the East China Sea

报道了首次分离于东海海域的三叶原甲藻(Prorocentrum triestinum Schiller)藻株号(LAMB100721),通过利用光学显微镜、荧光显微镜、扫描电镜及分子生物学方法,对其形态特征、显微结构和分子系统进化进行了详尽描述和鉴定。细胞长卵形或披针形,后端细长且尖,前端圆,最宽部位于细胞中央。顶刺长而显,三角状。壳面光滑,无刺或突起物。刺丝胞孔稀疏而不规则地分布于壳面边缘。叶绿体无具体形状,分布于整个细胞中,细胞核球形,位于中下部。老化的细胞可见细胞边缘的间接带,且间接带表面光滑。细胞长为19～25μm,平均值为(22.6±0.9)μm;宽为11～16μm,平均值为(13.2±1.1)μm。所测目标藻株的rDNA ITS序列长度为569bp,其中GC含量为47.6%。三叶原甲藻系赤潮种,为东海原甲藻春季大规模赤潮的伴随种。加强有害赤潮的预防和监测工作是减少危害的有效途径,而对赤潮原因种的准确识别和鉴定则是基础和关键。

Prorocentrum triestinum Schiller（LAMB100721） is first time isolated in the East China Sea（ECS）.Detailed morphological characteristic and molecular phylogenetics are described on the basis of observation under light microscopy,fluorescence microscopy,scanning electron microscopy and measurement of ITS sequences.The cells are lanceolate or heart-shaped.The anterior end is slightly excavated with an apical spine.The posterior end is pointed.The center of the cell is widest.Thecal surface is smooth,but contains tricocyst pores which are scattered apparently at the margin.The chloroplasts are irregular,distributed within the whole cell.The nucleus is rounded,located at the posterior part of the cell.The cell has a mean length of（22.6±0.9）μm（range 19-25 μm） and mean width of（13.2±1.1）μm（range 11-16 μm）.The sequence length of the strain LAMB100721 is 569 bp.The GC content is 47.6%.Prorocentrum triestinum is a causative species of red tide.It has been co-occurred with Prorocentrum donghaiense in the ECS.Therefore,the precise identification and detection of the causative species were important for monitoring and early warning of harmful algal blooms.