中国渤海与黄海沿岸珊瑚藻属2个近似种的形态分类及系统发育

Morphological classification and phylogeny of two similar species of genus Corallina from the Bohai and Yellow Sea coasts of China

为了从形态学和系统发育学上区分我国渤海与黄海沿岸珊瑚藻属的不同物种,从河北秦皇岛和山东青岛沿岸采集珊瑚藻样品,首先通过生物冷冻切片和显微拍照技术进行形态鉴定,在此基础上,利用3种分子序列,即rbcL、COI、UPA,对珊瑚进行系统发育分析,分别采用NJ法、ML法和ME法构建珊瑚藻属部分物种的系统进化树,明确物种间的亲缘关系.结果如下:①根据形态鉴定出了我国渤海和黄海沿岸珊瑚藻属的2个近似种,即珊瑚藻(Corallina officinalis)和小珊瑚藻(Corallina pilulifera);②两者虽然在外形上相似,但在主枝节间髓细胞层数、节间中肋状突起的有无以及孢子囊生殖窝有无长角等特征上存在差异;③观察了秦皇岛海域珊瑚藻生长发育特征的季节变化,为其形态分类鉴定提供了补充数据;④系统发育分析结果显示,部分样品与珊瑚藻聚为一枝.

In order to distinguish morphologically and phylogenetically the different species of the genus Corallina distributing along the coasts of Bohai and Yellow Sea of China,the samples of Corallina were collected from the coasts of Qinhuangdao of Hebei Province and Qingdao of Shandong Province respectively.Firstly,morphological identification was carried out by means of biological freezing microtome section and microscopic photography.On this basis,the phylogenetic analysis was carried out using three molecular sequences,i.e.rbcL,COI,and UPA.The phylogenetic trees of some samples were constructed by Neighbor-Joining,Maximum Likelihood and Minimum-Evolution methods,and their genetic relationships were clarified.The results were as follows:①Two similar species of genus Corallina are identified as Corallina officinalis and Corallina pilulifera according to the morphological results;②Although the two species are similar in appearance,there are differences in the number of medullary cell layers of the main branch,the costal protrusion on the intergenicula and the horns of tetrasporangial conceptacle;③The seasonal growth and development characteristics(March,May and September)of Corallina officinalis from Qinhuangdao were carefully observed,which provides supplementary data for its morphological classification and identifi-cation;④Phylogenetic analysis showed that some samples were closely related to Corallina officinalis and can be clustered into a single branch.