An estimation of genetic parameters of growth traits in juvenile turbot (Scophthalmus maximus L.) using parental molecular relatedness

The estimation of genetic parameters has played an important role in animal selective breeding for growth traits. Recently studies show that molecular markers can be incorporated into genetic evaluations. In order to improve the performance of an incomplete pedigree (i.e, only parents are known) in the genetic evaluations, 12 microsatellite markers have been applied in the estimation of the genetic parameters for body weight in a farmed population (n=1 890) of juvenile turbot (Scophthalmus maximus L.). A new relatedness called parental molecular relatedness (PMR) is estimated based on results of genotyping of 48 parents (31 males, 17 females) with microsatellites markers. The feasibility of PMR in estimation of genetic parameters is verified by comparison with pedigree related (PR) which is obtained from a complete pedigree. The results demonstrate that a high correlation (0.872) between them is found. Heritabilities are estimated using the PMR (0.52 +/- 0.13) and PR (0.55 +/- 0.22) with the same animal model. A cross-validation shows that the predictive abilities of models using the PMR and the PR are identical (0.81). From that, a conclusion can be made that PMR and PR predicted genetic values equally well in a population of juvenile turbot. Therefore PMR can be applied as an alternative of the PR when only parents are known. However, for a better performance, more markers and more families should be included in a further study.