Abstract

This study was conducted to compare and evaluate the productive performance characteristics of the base generation (F₀) of Nile tilapia, Oreochromis niloticus and Blue tilapia, Oreochromis aureus under the effect of interspecific hybridization and genetically modified breeding by introducing a fragmented purified DNA isolated from O. aureus or O. niloticus into the gonads of O. niloticus or O. aureus parent, respectively. The results showed that the growth performance, body composition and feed utilization parameters of genetically modified O. aureus or O. niloticustreated with O. niloticus or O. aureus DNA, respectively were improved significantly (P≤0.05) as compared to both purebred and interspecific hybridization (♀ O. aureusx ♂ O. niloticus and ♀ O. niloticus x ♂ O. aureus). RAPD analysis was used for constructing parsimony tree depicting relationships among the different genotypes studied. The hierarchical cluster analysis based on RAPD fingerprinting, grouped the six genotypes of fish into two major category groups. Within these major grouping, purebred of O. niloticus, O. aureus and their reciprocal hybrid grouped close together. Also, the dendrogram showed that the hybrid of ♀ O. aureus x ♂ O. niloticus appear to be more genetically similar to that of the hybrid ♀ O. niloticus x ♂O. aureus than that of the purebred of either O. niloticus or O. aureus. The other major group showed that O. aureus injected with O. niloticus DNA appear to be more genetic dissimilarity to that of O. niloticus injected with O. aureus DNA. The results of this study suggested that genetically modified O. niloticus and O. aureuswith higher growth rate can be produced using a feasible and fast methodology compared as to interspecific hybridization.

Key words: Productive performance, Oreochromis niloticus, Oreochromis aureus,inter-specific hybridization, genetically modified.