Genetic Relationship Between Three Kinds Of Hybrid Tilapia And Oreochromics Niloticus And O.aureus

This study studied the genetic relations between three kinds of hybrid tilapia and oreochromics niloticus and O.aureus at the level of morphology and molecule. In order to detect the heterosis of three kinds of hybrid and to explain the difference of capability of production at the level of molecule we compared the between-population index of similarity and between-population genetic distance of three kinds of hybrid to oreochromics niloticus and O.aureus. At the same time we distinguished the hybrid from oreochromics niloticus and O.aureus.by new statistic technology and software in morphology and established new means of morphology. This study grounded for breeding and culturing of tilapia theoretically and practically.The results of this experiment showed that there were great between-populationdistance between oreochromics niloticus and O.aureus. which indicated the gene oforeochromics niloticus ♀ × O.aureus ♂ was more heterozygous and showed the heterosisin oreochromics niloticus ♀ × O.aureus ♂ . The between-population index of similaritybetween oreochromics niloticus ♀ × O.aureus ♂ and oreochromics niloticus andO.aureus were equal nearly which also certified the heterosis of oreochromics niloticus♀ × O.aureus ♂ .there were high between-population index of similarity between(oreochromics niloticus ♀ × O.aureus ♂ ) ♀ × O.aureus ♂ and O.aureus whichindicated that (oreochromics niloticus ♀ × O.aureus ♂ ) ♀ × O.aureus ♂ resembledO.aureus in idioplasm.it was the same to (oreochromics niloticus ♀ × O.aureus ♂ ) 　?×(oreochromics niloticus ♀ × O.aureus ♂) ♂. the result of this experiment explained thepoor quality of (oreochromics niloticus ♀ × O.aureus ♂ ) ♀ × O.aureus ♂ and(oreochromics niloticus ♀ × O.aureus ♂ ) ♀ × (oreochromics niloticus ♀ × O.aureus♂ ) ♂ .for example, slow growth, poor food transformation etc. The results of thisstudy suggested that (oreochromics niloticus ♀ ×O.aureus ♂ ) ♀ × O.aureus ♂ and(oreochromics niloticus ♀ × O.aureus ♂ ) ♀ × (oreochromics niloticus ♀ × O.aureus♂ ) ♂ need more selective breeding and hybridization in order to improve the quality ofthem.In addition, products of 8323 were found to be molecular markers for identifying oreochromics niloticus and three kinds of hybrid tilapia.products of 8326 and S336 were found to be markers for identifying O.aureus and three kinds of hybrid tilapia.It is great meaningful to distinguish pure strain tilapia and hybrid in morphology. The results of this study showed that we could distinguish hybrid tilapia from pure strain tilapia by clustering conducting on metric characters, three kinds of hybrid resembled O.aureus from the result of clustering conducting on metric characters.