摘 要 ：通过形态学方法将中国淡水藻种库一株编号为FACHB-329的甲藻鉴定为楯形多甲藻不等变种Peridinium umbonatum var.inaequale Lemmermann,并且描述了此甲藻所产生的孢囊形态。还对该藻的SSU和LSU rDNA序列进行测序,系统发育分析的结果也支持形态鉴定。系统发育研究结果表明多甲藻属是多系起源的,本研究所用的多甲藻属类群可以形成两个大的分枝——Peridinium umbonatum类群形成的分枝和狭义多甲藻属类群(Peridinium sensu stricto)形成的分枝。并且形态学和分子数据都显示了P.umbonatum类群与狭义多甲藻属类群之间的差异。P.umbonatum类群形成的淡水单系类群虽然没有高度的自展支持但获得了不同的系统发育分析的支持,而狭义多甲藻属类群形成的单系类群获得了高度的支持。淡水多甲藻P.aciculiferum和P.wierzejskii则与海洋斯氏藻属关系密切。
Abstract:Using morphological taxonomy,we identified a freshwater dinoflagellate from the Freshwater Algae Culture Collection(strain No.FACHB-329) as Peridinium umbonatum var.inaequale Lemmermann by morphological taxonomy.We also described the morphology of its cysts.We sequenced the small and large subunit ribosomal DNA(SSU and LSU rDNA) for morphological identification.The phylogenetic results indicate that Peridinium as presently defined is polyphyletic and the taxa of our studied genus could be divided into two large branches: a clade of Peridinium umbonatum group and another clade of Peridinium sensu stricto group.Both of the morphology and molecular datas indicate that there are differences between P.umbonatum group and Peridinium sensu stricto group.Different phylogenetic results support P.umbonatum group may cluster into a monophyletic freshwater group in spite of the low bootstrap values,while the monophyletic Peridinium sensu stricto group had high bootstrap values.Freshwater P.aciculiferum and P.wierzejskii are very closely related to marine Scrippsiella.