Study On Molecular Systematics Of Bangia Atropurpurea

Bangia atropurpurea belongs to the eukaryotes, its alternate name is freshwater Bangia. According to "Flora algarum sinicarum aquae dulcis", B. atropurpurea is classified in Rhodophyta, Rhodophyceae, Bangiales, Bangiaceae, Bangia. At Present, there are two kinds of Bangia have been identified in China. The one is Bangia fuscopurpurea which is Widely distributed in coastal areas, the other is B. atropurpurea located in inland body of freshwater.In this paper, B. atropurpurea that collected from Niangziguan Spring of Shanxi between 37°58'N and 113°52'E. Combining with the traditional form of classification it's based mainly on molecular systematic. The rbcL gene, 18S rRNA gene and col gene of these samples were amplified, sequenced and analyzed. The results showed the length of rbcL gene is 1315 bp, the length of 18S rRNA gene is 1777 bp, the length of co1 gene is 714 bp. The different regions of B. atropurpurea had the same gene. Four phylogenic rees were constructed based on sequences obtained and downloaded from GenBank by Maximum likelihood method, Neighbour-joining method, Maximum parsimony method and Bayesianian methods. Phylogenetic trees showed that B. atropurpurea from different regions are in the same branch, while distinct from B. fuscopurpurea of other regions evidently. B. atropurpurea is on the more important evolutionary period from phylogenic trees. The results of phylogeny trees supported the opinion that B. atropurpurea have separated from B. fuscopurpurea for a long term. Genetic distance showed that average genetic distance is smaller between B. atropurpurea from different regions and smaller between different B. fuscopurpurea. But the distance is large between B. atropurpurea and B. fuscopurpurea. These evidences indicate that B. atropurpurea from Niangziguan Spring was a distinct species from B. fuscopurpurea. In addition, the psaA gene, psbA gene, ITS sequences, cox2-3 gene of these samples were amplified and sequenced. The results showed the length of psaA gene is 811 bp, the length of psbA gene is 914 bp, the length of ITS sequences is 1226 bp, the length of cox2-3 gene is 473 bp. The phylogenetic trees haven't done for the reasons of regional distribution and algae collection. Reference datas may be limited in B. atropurpurea even in B. fuscopurpurea. The study focused on the gene sequences provided the systematic information for the molecular systematics research of Bangiacean algae and offered effective datas.