Sixties primers were used for dna amplification and a total of 237 amplification products range from 450bp to 2500bp were generated . a similarity matrix for all pairwise comparisons was calculated using nei and li ' s formula and then transformed to distance matrix . dendrograms were constructed by applying unweighted pair - group arithmetic average ( upgma ) and neighboring - jointing cluster analyses using the phylip software 在第二部分，应用改进的ctab法提取了石莼属和浒苔属各3个种及作为对照的刚毛藻的基因组dna ， 60个引物被用于扩增，共获得237个片段大小在450 - 2500bp之间的扩增片段，依据nei和li ( 1979 )的公式计算出样品成对比较的相似性距阵并换算成遗传距离，应用phylip软件包，按照upgma法和n - j法分别构建聚类图。
