Abstract:Heritability is the most basic parameter for estimation of selection effect, breeding value and comprehensive selection index. It is widely applied in the determination of the selection method and artificial breeding practice. In this study, the heritability of body length, body weight and the number of pallet were estimated in 9-month-old sea cucumber (Apostichopus japonicus), with the goal of providing heritability reference for breeding practice. A total of 29 mature sea cucumbers from five different populations were selected as parents. Six dams and twenty-three sires were mated by unbalanced nested design using artificial insemination. Each dam was mated with 2 to 5 sires, producing 6 half-sib families and 23 full-sib families. Full-sib families were reared separately under identical environmental conditions. Thirty to fifty individuals from each full-sib family were randomly selected for assessment of three economic traits: body length, body weight and the number of pallet in 9-month-old sea cucumber. The heritability of body length, weight and the number of pallet was compared statistically using GLM (General Linear Model) procedure of the SPSS software. The results indicated that the heritability of body length in full-sibs, maternal half-sibs and paternal half-sibs was estimated to be 0.86, 0.87 and 0.85, respectively. The heritability of body weight in full-sibs, maternal half-sibs and paternal half-sibs was estimated to be 0.46, 0.20 and 0.73, respectively. The heritability of the number of pallet in full-sibs, maternal half-sibs and paternal half-sibs was estimated to be 0.37, 0.43 and 0.32, respectively. Results obtained from t test showed that the heritability of body length and body weight in paternal half-sibs was significant (P<0.05), and the heritability of body length and body weight in full-sibs was highly significant (P<0.01). By contrast, the heritability of the number of papilla in full-sibs, maternal half-sibs and paternal half-sibs was not significant. The estimation of heritability of the three economic traits in the large-scale seeding program could provide theoretical basis and technical reference for future artificial breeding of A. japonicus.
