Genetic parameter estimates in a clonally replicated progeny test of teak (Tectona grandis Linn. f.)

Teak (Tectona grandis Linn. f.) has been planted extensively in the tropics for its highly valued timber. We analysed data from a 3.5-year-old teak progeny test with clonal replication located in northern Australia. Additive and non-additive genetic variances were estimated for commercially important traits. Trees originating from seedlings were on average 2% taller and 4% straighter than those of the same genotype originating from cuttings. Nonadditive genetic variance represented 35-50% of total genetic variance for growth traits and 63% of total genetic variance for incidence of flowering. Narrow-sense heritability was 0.22 for diameter, 0.18 for height and volume, 0.07 for stem straightness, 0.05 for insect defoliation, 0.03 for epicormic sprouts and 0.30 for incidence of flowering ( estimated on an assumed underlying continuous scale). Broad-sense heritability was 0.37 for diameter, 0.28 for height, 0.35 for volume, 0.12 for stem straightness, 0.06 for insect defoliation, 0.12 for epicormic sprouts and 0.71 for incidence of flowering. Positive correlations were found between tree volume and flowering and between tree volume and stem straightness. The presence of sizeable non-additive variance supports the selection and deployment of clones to capture the full extent of genetic variation in commercially important traits.