我国沿海拟菱形藻属的2新记录种及其产毒特征分析

Two New Records of Diatom Genus Pseudo-nitzschia from Chinese Waters and Analysis of Their Domoic Acid Production

摘要:

为澄清我国沿海拟菱形藻属(Pseudo-nitzschia)的物种多样性,并确认中国海域拟菱形藻属是否具有产生多莫酸(Domoicacid)的能力,采用毛细管显微操作技术从我国沿海水体中分离、纯化拟菱形藻细胞,建立了单克隆培养株系,并基于核糖体转录间隔区ITS1-5.8S-ITS2 序列构建了分子系统树。结果表明,结合在光学显微镜和透射电镜下观察的形态学特征和分子系统发育分析数据,鉴定到我国拟菱形藻属的2新记录种:银河拟菱形藻(P. galaxiae Lundholm & Moestrup)和微孔拟菱形藻(P. micropora Priisholm, Moestrup & Lundholm),对其形态学特征进行了详细描述,并与相似种类进行了比较研究。利用高效液相色谱(HPLC)技术对多莫酸特征进行了检测,结果表明培养株系并不产生多莫酸。这些为我国拟菱形藻属物种多样性和产毒特征研究提供了基础数据。

Abstract:

In order to clarify the species diversity of toxic diatom genus Pseudo-nitzschia in domestic coastal, and confirm the ability of domoic acid production from Chinese Pseudo-nitzschia strains, single cells or single chains of Pseudo-nitzschia species were isolated and purified using glass micropipette under invert microscope, and finally the monoclone culture strains of Pseudo-nitzschia species were established and maintained in the laboratory. The morphological characteristics and ultrastructure of colony were observed under light microscope and electron transmission microscope. The molecular phylogenetic tree was constructed based on sequences of internal transcribed spacer (ITS1-5.8S-ITS2). The results showed that two new records of Pseudo-nitzschia from China were identified, i.e., P. galaxiae Lundholm & Moestrup and P. micropora Priisholm, Moestrup & Lundholm. Their detailed morphological characteristics have been described and compared with similar species. All strains of these two new records had no domoic acid (DA) production by using high performance liquid chromatography (HPLC). These would provide basic data for studying species diversity and domoic acid production of genus Pseudo-nitzschia in the China sea.