Genetic Parameter Estimates for Maritime Pine in the Atlantic Coast of North-west Spain

One hundred and seven half-sib families of Pinus pinaster planted at four sites in Galicia (NW Spain) were evaluated at age 8 for growth (height, diameter, volume and mean internode length), stem form (straightness, leaning, forking) and branching characteristics (branch diameter, angle and number and total number of whorls). The analyzed half-sib families were obtained from first-generation plus trees selected for the coastal area breeding programme in Galicia. Estimates of individual and family heritabilities and genetic correlation among traits are presented. Total height, average internode length, number of whorls and branch angle had moderate individual heritability estimates (0.1 1-0.37). Family heritabilities were moderate to high for almost all traits. Unfavourable genetic correlations were detected between growth and stem form traits and between polycyclism and growth. The average internode length appeared to be an interesting selection trait. It combines both polycyclism pattern and growth, shows moderate individual heritabilities (0.21-0.27) and high family heritabilities (0.67-0.74), and was favourably genetically correlated with other interesting traits. The results are compared with published data and discussed in relation to their implications in the breeding activities.