藻类及陆生高等植物叶绿体16Sr RNA基因进化谱系及同源性分析

Analysis of 16S rRNA sequence of the Dunaliella salina chloroplast

目的 :了解杜氏盐藻与其他藻类和高等植物间的亲缘关系。方法 :将杜氏盐藻的叶绿体 1 6SrRNA序列与一些藻类和陆生植物叶绿体的 1 6SrRNA序列资料进行同源性比较与分析 ,并构建进化树。结果 :进化树显示整个植物界明显分为 3个大的类群 :蓝藻门、红藻门、隐藻门、金藻门、褐藻门、硅藻门和甲藻门形成一个类群 ,裸藻门单独形成一个类群 ,而绿藻门和陆生高等植物共同形成一个大的类群。陆生高等植物间的亲缘关系非常近 ,拥有一个共同的绿藻祖先 ,而杜氏盐藻、莱茵衣藻等所归属的团藻目则与其他绿藻及高等植物分离 ,独立形成一个极为分散的类群。结论 :杜氏盐藻所隶属的团藻目属于较为原始的绿藻 ,彼此之间亲缘关系较远 。

Aim: To find out the relationship of Dunaliella salina and the other algae and plants. Method: The 16S rRNA sequences of the chloroplast of Dunaliella salina, some algae and plants were analyzed and the phylogram was constructed by comparing homology of the sequences. Results: The phylogram showed that the plant kingdom was divided into three groups. Group A consisted of Cyanobacteria, Rhodophyta, Cryptophyta, Chrysophyceae, Phaeophyceae, Bacillariophyta and Dinophyceae which were all lower algae without chlorophyll b, Group B was composed of Euglenida, and Group C comprised Chlorophyta and higher plants including Bryophyta, Filicophyta and Spermatophyta. And the higher plants had a consanguineous relationship and shared a common green alga ancestor, while the Volvocales had a distant relationship with other green algae and higher plants. Conclusion: The Volvocales to which Dunaliella salina belongs are primordial green algae which have separated from other green algae and higher plants for a long time and have distant relationships with one another.