作　　者： ; ;

机构地区： 中山大学生命科学学院生物工程研究中心

出　　处： 《中山大学学报（自然科学版）》 1999年第1期7-11,共5页

摘　　要： 通过计算机联网从Ｇｅｎｂａｎｋ中及实验分析获取亚历山大藻属Ａｌｅｘａｎｄｒｉｕｍ共５种１２个株系的ｒＤＮＡＩＴＳ序列，并采用计算机分析软件包对其进行分析及构建树图结果表明，亚历山大藻属不同种，种间序列有显著差异（核苷酸差异大于０２０），而种内个体间ＩＴＳ区序列则非常相似（仅００１差异），表明了ＩＴＳ区用于该属的分类鉴定是一个较稳定的指标．根据序列比较结果，得出：①形态非常相似的Ａｃａｔｅｎｅｌａ，Ａｔａｍａｒｅｎｓｅ有毒种类，分子水平有明显差异，不同意将这两个种称为“ｔａｍａｒｅｎｓｅｃｏｍｐｌｅｘ”；②根据种间序列核苷酸的差异系数，提出了该属种间界定的分子标准，同时对形态学鉴定的某些株系，如ＡｔａｍａｒｅｎｓｅＣＵ１５等提出了异议．可以看出，ＩＴＳ区的研究从一个新的角度为海洋微藻种的界定提供了很好的依据． Alexandrium ,a dinophyceous genus,which consists of more than 30 species, includes a lot of closely related toxic species, such as A tarmarense/A catenella “species complex” To resolve their taxonomic ambiguities, new methods are being introduced The sequences of 5 8S rDNA and flanking internal transcribed spacers 1 and 2 from 12 strains of 5 species in Alexandrium were acquired online through the internet system Based on the sequence analyses and comparisons using computer program, the criteria for the species boundaries and the taxonomic ambiguities in Alexandrium were discussed The results are as follows:① A tamarense/A catenella “species complex”, which was most closely related in morphology , has high distance value between two species(>0 20).However, the distance values between the intraspecific strains were extremely low(<0 01).This indicates that, A tamarense/A catenella should be classified as two different species instead of as a “species complex”;② strains WKS 01 and CU 15, identified as the nontoxic strains of A tamarens morphologically, show clear differences with the toxic strains of A tamarens by the sequence comparison of rDNA ITS, distance values between WKS 1,CU 15 and the toxic strains of A tamarens was 0 198～0 201 and 0 350～0 351,respectively.Considering the molecular characteristics, strains WKS 1 and CU 15 cannot be treated as the same species of toxic A tamarense

关 键 词： 亚历山大藻属 分子标准 藻类 海洋 种间界定

领　　域： [生物学]