Abstract
Inter-simple sequence repeat (ISSR) analysis was used to develop fish species-specific molecular markers for four Tilapia species (Oreochromis niloticus, Oreochromis aureus, Tilapia zillii and Sarotherodon galilaeus). 12 ISSR primers were tested to assess the effectiveness of ISSR analysis in discriminating among the four applied fish species. Some ISSR markers were detected as species-specific for O. niloticus, O. aureus, S. galilaeus and T. zillii species. The Phylogenetic relationships among applied fish species were reconstructed using deferent methods (Sokal & Sneath, Dice and Simple match coefficients). The percentages of polymorphism were ranged from 0% to 67% within S. galilaeus, while polymorphism values were ranged from 0% to 100% in the other studied fish species. The highest genetic dissimilarity value was observed between O. aureus and T. zillii. In contrary, the lowest dissimilarity value was observed between O. niloticus and O. aureus. ISSR analysis was an attractive tool for species identification. These markers were recommending when coupled with appropriate statistical analyses in fish species identification and classification. [Y.M. Saad, M. A. Rashed, A. H. Atta and N.E. Ahmed. Genetic Diversity among Some Tilapia species Based on ISSR Markers. Life Sci J 2012; 9(4): 4841-4846] (ISSN: 1097-8135). http://www.lifesciencesite.com. 728