Effect of additive, dominant and epistatic variances on breeding and deployment strategy in Norway spruce

Genetic variances are important parameters and have a great impact on the determination of optimal breeding strategies of tree species. A large clonal testing program was conducted to estimate additive, dominant and epistatic variances for the development of breeding and deployment strategies in Norway spruce (Picea abies (L.) Karst.). The analysis results of genetic variation for growth and wood properties in two clonal trials in central Sweden indicated that the important sources of total genetic variation were both additive and non-additive genetic variances. Additive genetic variation accounted for the majority of total genetic variation for diameter at breast height (DBH) and wood quality traits, whereas non-additive genetic variation was significant only for tree height at an early age. Predicted genetic gain was the highest for clonal deployment based on best tested (replicated) clones (4.7-65.3 per cent), followed by clonal deployment of the best individual trees from a full-sib family trial (3.5-57.7 per cent), and the deployment of seedlings generated by open-pollination (1.9-48.3 per cent)