Genetic parameters and performance stability of white spruce somatic seedlings in clonal tests

► We found a large variability among clones for growth and branching characteristics. ► Of all the characteristics studied, height had the highest heritability. ► The selection of the top 20 clones provided a genotypic gain in height of 4%. ► We observed high genotypic correlations between growth and branching characteristics. ► The G × E interaction was low and the correlation between the two sites was high.