SEQUENCE ANALYSIS OF 18s DNA OF <i>Melosira</i> sp., <i>Dunaliella</i> sp., <i>Isochrysis</i> sp. AND <i>Porphyridium</i> sp.


Phytoplankton has high level of biodiversity. In previous years phytoplankton was identified by their morphological characters. However, their morphology might change in different environments. These difficulties can be overcome by comparing their 18S rDNA sequences. This research is aimed to verify the identity of Melosira sp., Dunaliella sp., Isochrysis sp. and Porphyridium sp. Here, PCR method was used to amplify 18s DNA sequences. Three primer pairs were used, i.e. 18S-F and 18S-R; 501F and 1700R; 18S-2F and 18S-2R. PCR products were sequenced. MEGA5 was used to make phylogenetic tree. Genus verification for Isochrysis sp., Dunaliella sp. and Melosira sp. were conducted successfully using Blast and phylogenetic tree. 18s DNA sequence of Porphyridium sp. shows an interesting result and needs further verification.

Keywords: Phytoplankton, Melosira sp., Dunaliella sp., Isochrysis sp., Porphyridium sp.

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