identification of chlorophyceae based on 18s rdna sequences from persian gulf.

background and objectives: chlorophyceae are important constituents of marine phytoplankton. the taxonomy of chlorophyceae was traditionally based solely on morphological characteristics. in the present research project, genetic diversity was investigated to analyze five species of chlorophyceae from waters of the persian gulf. materials and methods:   a clone library of the ribosomal small subunit rna gene (18s rdna) in the nuclear genome was constructed by pcr, and then, after examining the clones, selected clones were sequenced. the determined clone sequences were analyzed by a similarity search of the ncbi genbank database using blast. results and conclusion: eleven sequences were identified correctly and used for phylogenetic analysis. we identified species of chlorophyta ( chlorella sorokiniana, chlamydomonas sp., neochloris aquatic, picochlorum sp. and nannochloris atomus ) without the need to conduct extensive colony isolation techniques. therefore, this improved molecular method can be used to generate a robust database describing the species diversity of environmental samples.