1 Breeding for wood properties of radiata pine in New Zealand S. Kumar, R. D. Burdon and G. T. Stovold Ensis Genetics, Private Bag 3020, Rotorua, New Zealand. Email: Satish.Kumar@ensisjv.com Tel: 64 7343 5899; FAX: 64 7348 0952 Abstract Two genetic trials were sampled for studying variation and inheritance of wood properties and diameter at breast height (DBH) in radiata pine (Piuns radiata D. Don). The study involved: (1) Five female testers with 56 pollen parents, ca five individuals per full-sib family, at ages 8 and 13 years; and (2) 33 pair-crosses (from 33 parents) × 10 clones/cross × six ramets/clone, at age 8-9 years. Sampling was at one site for each trial. Wood properties studied, directly or indirectly, were density, acoustic velocity, longitudinal shrinkage (LS), collapse on drying, and resin pockets (as resin bleeding - ERB). Coefficients of variation (CVs) for density, velocity and DBH were about 7%, 11% and 13%, respectively. Estimated broad-sense heritabilities (H 2 ) around age 8 were around 0.6 for all wood properties except ERB, but narrow-sense (h 2 ) estimates were much lower for all except density. For DBH estimated h 2 and H 2 were ≈0.25 and ≈0.3 respectively. DBH showed generally adverse genetic correlations with wood properties. Notable correlations between wood properties involved Velocity and LS (r g ≈ -0.9), and density and collapse (-0.3 to -0.6). Even allowing for some very indirect measures of traits, and generally adverse genetic correlations with DBH, the prospects for genetic improvement of the wood properties are encouraging.