Predicted genetic gain and realised gain in stand volume of Eucalyptus globulus

Realised gains in stand volume of Eucalyptus globulus Labill. families at 7-9 years were compared with gains predicted at 3. 5 years. Gain predictions were based on height, diameter at breast height (DBH), sectional area, and stem volume for 153 full-sib families and 18 commercial checks in five-tree line plots on three West Australian sites. Single-site narrow-sense heritability estimates were 0. 12-0. 24 for height, 0. 08-0. 12 for DBH, 0. 09-0. 13 for sectional area, and 0. 14-0. 19 for stem volume. Genetic dominance effects were significant (p & 0. 05) in most cases, and the estimated dominance/additive genetic variance ratio was heterogeneous for height and DBH. Stand volume was measured for 93 of the same families and checks in 40-tree block plots on four sites. Heritability of stand volume was 0. 25-0. 76, with an across-sites estimate of 0. 41. Dominance effects were statistically absent at two sites. Estimated region-wide additive genetic correlations between selection traits (in line plots) and stand volume (in block plots) ranged from 0. 86 to 0. 90. Estimated stand volume gain was 23 % of the mean for the best 12 % of families and 14 % of the mean for the best 24 % of families. Realised gain was under-estimated by predictions based on height, DBH, and sectional area, which had smaller coefficients of additive variation than did stem volume. It is concluded that although BLUP analysis of early-age height and DBH can provide for indirect selection on E. globulus stand volume, analysis of stem volume is required to predict genetic gain at an appropriate scale. © 2012 Springer-Verlag.