| This study explored the use of amplified fragment length polymorphism (AFLP) technology in inter-species identification and genetic characteristics analysis of P. olivaceus and P. dentaus. A group of 60 individuals for two populations were surveyed using 8 different primer combinations. A total of 379 bands (size range 60–1000 bp) were generated. Species differed in the levels of genetic diversity among individuals, with 53.83% in P. dentaus and 22.22% in P. olivaceus of the bands scored being polymorphic. The P. olivaceus population tended to have a lower (P < 0.05) percentage of loci polymorphic than P. dentatus. Percentages of species-specific markers for the two populations were 27.3% and 29.61% respectively. The average heterozygosity of P. olivaceus and P. dentaus was 0.0701 and 0.1556, and Shannon diversity index was 0.1044 and 0.2378, respectively. Average genetic distance among individuals of the same species were 0.0705 (from 0.0214 to 0.1377) in P. dentatus and 0.1656 (from 0.0629 to 0.2338) in P. olivacus, while the average inter-species genetic distances between P. dentatus and P. olivaceus population was 0.6328. This study used AFLP technology as a feasible approach in inter-species genetic information analysis. Such information is very useful for future broodstock selection, inter-species hybridization management and further understanding the genetic basis of heterosis.In this study, P. olivaceus(♀)5×P. dentaus(♂)8 factorial mating design was employed to examine the heritability of growth-related traits based on dam half-sib and sire half-sib families. A total of 600 offspring 42 days after fertilization were collected randomly from the same mixed group, and body weight and length were recorded. This study was initiated to assess the feasibility of parentage determination in hyride populations. The genetic variations of P. olivaceus, P. dentatus, and their hybrids polulation were assessed at 10 microsatellite loci (Po1, Po13, Po20, Po35, Po42, Po48, Po56, Po58, Po91, Poli23TUF). All loci are polymorphism.When marker data from 3 loci were combined, the assignment success of progeny to their true parental couple increased to 80% in parentage identification with known parental and filial information. Out of 600 offspring, more than 400 was assigned to their parental pairs exclusively in mixed families groups. Based on these results, we conclude that the use of a number of microsatellite markers represents a realistic and effective alternative to physical tagging in a selection program and it allows the identification of parental effects on offspring performances from early life stages.During the heterosis analysis of hybride, before 181 day, for weight and length no heterosis was found, the heterosis rate was negative. After 196 day,the hybrids began to show positive heterosis and increase. At 256 day,the heterosis rates for length and weight was 14.29%, and 59.78%, respectively. At 271 day, the heterosis rates for length and weight was 27.36%, 102.32%, respectively.Estimates of half-sib family heritability (h2S) of five growth-related traits ranged from h2S 0.00146-0.719, full-sib family heritability(h2D) of five growth-related traits ranged from 0.00121-0.632, average heritability (h2SD) of five growth-related traits ranged from 0.001335 - 0.6755. It is concluded that selective breeding for growth-related traits at an early life stage could affect growth at a later life stage. Selective breeding for juvenile hybrid for increased weight gain can be successful.
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