一株海洋藻类的分子鉴定及分类

Molecular identification and classification of a marine algae ST3

海洋藻类种类繁多,由于形态的易变性和生活史的复杂性,传统的形态分类往往十分困难。分子标记技术的发展,使DNA分子成为区分物种的有效手段,成功地解决了许多疑难藻种的分类鉴定问题。本研究测定和比较了一株海洋藻类ST3的18s rDNA基因部分核苷酸序列,序列长度为1733bp,通过与GenBank中序列数据进行比较分析,对其进行了分子鉴定和分类。研究结果表明藻株ST3属于硅藻门海链藻目,与骨条藻属的亲缘关系较海链藻属为近,但与骨条藻属遗传距离远大于骨条藻属种间差异,说明ST3可能是硅藻门海链藻目新的藻属。18s rDNA可用于海洋藻类分子分类与鉴定。

Marine algae are numerous,and often difficult to be identified and classified based on traditional taxonomy due to variable morphological characters and complicated life histories.The development and application of molecular markers make DNA to be a useful tool to differentiate different species and have successfully determined the species identities of many problematic taxa.1733bp nucleotides of 18s rDNA from a marine algae ST3 were determined in this study.The sequences were then used as molecular criteria to investigate the algae identities and their classification.The result showed that ST3 belonged to Thalassiosirales,Bacillariophyta,although ST3 was more closely related to Skeletonema than did Thalassioria,considerable genetic distance between ST3 and Skeletonema existed,so ST3 might be a new genus in Thalassiora.18s rDNA was useful to identify and classify marine algae.