Genetic parameters of growth and wood quality traits in Picea abies

Genetic parameters were estimated for wood and growth traits in two 19-yr-old clonal trials and a 40-yr-old full-sib progeny trial of Norway spruce [ Picea abies ( L.) Karst.]. In the clonal trials high (> 0.4) broad-sense heritabilities were found for wood density traits, lignin content, number of internal cracks, growth traits, spiral grain and number of resin canals. Moderate (0.2-0.4) heritabilities were found for tracheid lumen diameter and cell wall thickness, microfibril angle and tracheid length, while low heritabilities (< 0.2) were found for pulp yield, fibre strength, wood stiffness and wood colour. Lignin content and pulp yield showed low genetic variation, whereas the genotypic coefficient of variation for most other traits ranged between 5 and 15%. Most traits showed low levels of genotype by environment interaction. Among the wood properties, latewood proportion, earlywood density and ring density showed significant, adverse correlations with volume in both clonal trials.