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Genetic Diversity of Two Tilapia Species (Oreochromis Niloticus and Sarthrodon Galilaeus) Using Random Amplified Polymorphic DNA
Abstract
Introduction:
In this study, the genetic variability in eight populations of Oreochromis niloticus and seven populations of Sarotherodon galilaeus was estimated using molecular markers.
Materials and Methods:
Fish specimens were collected from eight sites representing the White Nile, Blue Nile and the River Nile. Tissue samples from gills and dorsal fin were removed from individual specimens and preserved separately in absolute ethanol prior to molecular analysis by RAPD-PCR using eight primers. DNA analysis using OPA-04, OPA-13, OPA-03, OPA-06, OPA-07, OPA-09, OPA-10 and RAPD-8 produced different bands for each.
Results and Discussion:
The total bands generated by the primers were: 17, 16, 18, 12, 12, 14, 14, and 17. They were in the range of 100 to 1020 bp. Levels of variability were estimated by the proportion of polymorphic bands obtained by each primer within a population. The range of variability was wider in O. niloticus (46.0 to 91.7) compared to S. galilaeus (56.2 to 83.3). The dendrogram obtained differentiated the populations into 22 sub-clusters. Oreochromis niloticus from Al Kalakla exhibited a high level of genetic diversity. This diversity is evident among and within the studied populations, as estimated by RAPD-PCR techniques.
Conclusion:
To promote tilapia production, the study recommended increasing genetic variation within broodstocks by crossing high similarity breeds with low similarity ones.
