我国南部海区底栖原甲藻属(Prorocentrum)的生物多样性、系统发育及产毒特性研究

The benthic dinoflagellate Prorocentrum C.G.Ehrenberg has a cosmopolitan distribution that extends from temperate to tropical oceans. It is one of the important participants in marine benthic ecosystems. The genus Prorocentrum also contains potentially toxic species. Increases in particular concern to this genus due to the outbreaks of toxic blooms which associated to the diarrhetic shellfish poisoning (DSP). The DSP which produced by Prorocentrum are responsible for the common algal toxin-related illnesses and health effects. Morphological variation in Prorocentrum species is common. Differences in one species existed in the morphology, phylogeny and toxicity among strains from different locations. The benthic species of Prorocentrum in Chinese waters is poorly studied. The coastal regions in the South China Sea has typical tropical and subtropical environments for benthic dinoflagellates growth and distribution. We propose to study the taxonomy, phylogeny, biodiversity, distribution and toxicity of the benthic Prorocentrum in this region. The following scientific questions will be answered through this project: How many Prorocentrum species and/or morphotypes are there in this area (taxonomy and biodiversity)? What the relationships among these species and the others which collected around the world in the phylogenetic trees (phylogeny)? What the distribution patterns of the sampling sites in each season (distribution)? Is there any toxic species (toxicity)?

海洋底栖原甲藻（Prorocentrum)是一类广泛分布于热带、亚热带和温带海域的附着型甲藻，是底栖甲藻中最大的类群之一。许多底栖原甲藻能产生DSP毒素并通过食物链传递到人类，严重威胁水产品安全和人类健康。底栖原甲藻细胞形态具有较高的多变性，不同株系在形态、系统发育和毒性上存在差异，具有较高的多样性。本项目拟通过光镜、荧光显微镜和扫描电子显微镜对我国南海区底栖原甲藻进行系统的形态学研究；借助分子生物学方法明确其在系统发育上的地位；结合生态调查样品阐明其种类多样性和群落结构特征，确定底栖原甲藻的生物地理分布；利用液相色谱串联质谱仪测定毒素，明确底栖原甲藻的毒性。本研究结果将为深入我国海洋藻类分类学研究提供依据，为深入研究我国海洋底栖原甲藻的系统分类和多样性奠定基础，有利于全面了解我国海洋生物多样性和海洋资源，对水产品安全、人类健康、藻类水华监测具有积极的意义。

海洋底栖甲藻主要分布在热带和亚热带的岛礁，原甲藻是广泛分布的一个类群。本研究选取我国南部海域包括海南、广西、福建、台湾、西沙群岛等地区部分岛礁为研究对象，对以上地区的海洋底栖原甲藻进行了系统分类、系统发育及毒性的研究，获得了以下研究结果：.1.系统分类的结果表明，本研究共鉴定出底栖甲藻14种，隶属于原甲藻属（Prorocentrum），蛎甲藻属（Ostreopsis），Coolia，4个属，其中P. cf. maculosum，P. concavum，P. fukuyoi，P. cf. emarginatum，P. panamense，P. borbonicum 和P. elegans, O. ovata，O. lenticularis 9个种中国的新记录种，其它的种分别是P. lima，P. rhathymum，C. malayensis，C. tropicalis，C. canariensis。.2.系统发育分析的结果与系统分类的结果在种水平上一致，进一步确定了结果1中的各底栖甲藻的准确位置。.3.对利马原甲藻（P. lima）进行了种下分类，共鉴定出5个利玛原甲藻的种下形态学分类单位。通过对LSU和ITS区序列分子测序，建立分子系统发育树，系统发育分析的结果与系统分类的结果在种水平上一致。其中利马原甲藻变型1和2的形态特征存在显著差异，但二者以较高支持率聚在系统发育树的相同分支上，且LSU和ITS序列差异分析显示二者遗传上无差异，再次证实了利马原甲藻种内存在形态多样性。.4.毒性分析的结果表明，所有已检测的利马原甲藻（P. lima）和P. cf. maculosum株系都能产生冈田酸（OA），利马原甲藻的部分株系既能产生OA，又能产生DTX-1。