| Home | E-Submission | Sitemap | Contact Us |  
Algae > Volume 24(3); 2009 > Article
Algae 2009;24(3): 129-138. doi: https://doi.org/10.4490/algae.2009.24.3.129
Comparative Molecular Analysis of Freshwater Centric Diatoms with Particular Emphasis on the Nuclear Ribosomal DNA of Stephanodiscus (Bacillariophyceae)
Jang-Seu Ki*
Department of Life Science, College of Natural Sciences, Sangmyung University, Seoul 110-743, Korea
*Corresponding Author  Email: kijs@smu.ac.kr
DNA-based discrimination of species is a powerful way for morphologically otherwise similar species, like centric diatoms. Here, the author sequenced long-range nuclear ribosomal DNAs, spanning from the 18S to the D5 region of the 28S rDNA, of Stephanodiscus, particularly including a Korean isolate. By comparisons, high DNA similarities were detected from the rDNAs of nine Stephanodiscus (>99.4% in 18S rDNA, >98.0% in 28S rDNA). Their genetic distances, however, were significantly different (Kruskal-Wallis test, p < 0.01) compared to two related genera, namely Cyclotella and Discostella. In addition, genetic distances of 18S rDNAs were significantly different (Student’s t-test, p = 0.000) against those of the 28S rDNAs according to individual genera (Cyclotella, Discostella, and Stephanodiscus). Phylogenetic analyses showed that Stephanodiscus and Discostella showed a sister taxon relationship, and their clade was separated from a cluster of Cyclotella (1.00 PP, 100% BP). This suggests that Stephanodiscus has highly conserved sequences of both 18S and 28S rDNA; however, Stephanodiscus is well-separated from other freshwater centric diatoms, such as Cyclotella and Discostella, at the generic level.
Key words: freshwater diatom, nucleotide divergence, phylogeny, ribosomal DNA, Stephanodiscus

PDF Links  PDF Links
Full text via DOI  Full text via DOI
Download Citation  Download Citation
CrossRef TDM  CrossRef TDM
Related article
Editorial Office
[14348] A-1716, Gwangmyeong Trade Center, 72 Iljik-ro Gwangmyeong-si. Gyeonggi-do, Korea
Tel: +82-2-899-5980  Fax: +82-2-899-5922    E-mail: editalgae@gmail.com
About |  Browse Articles |  Current Issue |  For Authors and Reviewers
Copyright © The Korean Society of Phycology.                 Developed in M2PI