南海赤潮亚历山大藻的分子鉴定及“塔玛复合种”的分子系统发生分析

Molecular identification of red tide Alexandrium isolated from the South China Sea and phylogenetic analysis on "tamarensis complex"

利用SSU rDNA和ITS分子指标,结合GenBank和其他文献中的基因序列构建了系统树,对一株分离自我国南海的亚历山大藻"塔玛复合种"NH01进行了鉴定,发现SSU rDNA和ITS序列构建的系统树中,不同地理基因型的"塔玛复合种"均构成独立分支。与我国沿海所有的"塔玛复合种"一致,NH01也属于"亚洲温带"型。探讨了SSU rDNA和ITS分子指标用于塔玛和链状亚历山大藻鉴别的可行性,比较了2种不同的基于ITS序列的亚历山大藻的系统分类方法。认为SSU rDNA和ITS序列均可以应用于亚历山大藻种甚至种下水平的检测,可以准确判断其地理基因型。提出利用SSU rDNA和ITS等核酸序列标记的方法作为鉴定、调研我国海域的亚历山大藻"塔玛复合种"的常规手段。通过比对不同地理基因型的ITS序列,确定了一段DNA序列,可以用于鉴别不同地理基因型的亚历山大藻"塔玛复合种"。

to identify an Alexandrium ＂tamarensis complex＂ NH01 isolated from the South China Sea,phylogenetic trees were constructed with SSU rDNA and ITS sequences combined with that from GenBank and literatures.In both SSU rDNA and ITS phylogenetic trees,＂tamarensis complex＂ of different geographical genotypes were subdivided into independent clades.Consistent with other ＂tarmarensis complexes＂ isolated from China＇s coast area,NH01 also are ＂temperate Asia＂ type.The feasibility of identification of ＂tamarensis complex＂ with SSU rDNA and ITS sequences was conducted,and two kinds of system classification methods based on ITS sequence were discussed.SSU rDNA and ITS sequences can be used as molecular markers to identification Alexandrium between or even within species,can accurately determine their geographic genotype.Suggesting that a SSU rDNA and ITS nucleotide sequence tag approach is used as a routine method to identify,investigate Alexandrium of China＇s coast.Meanwhile,a DNA probe based on ITS sequences was identified and could be used to identify different geographical genotypes of ＂tamarensis complex＂.