Eucalyptus nitens genetic parameters

Eucalyptus nitens (Deane et Maiden) Maiden is a significant plantation species in temperate regions of the world, with breeding occurring in Australia, Chile, South Africa, and New Zealand. We reviewed published genetic parameters from over 100 field trials and calculated average values for key growth, wood property, tree architecture, and fitness traits. Parameter estimates from control-pollinated progeny trials were rare. However, numerous parameter estimates were available from open-pollinated progeny trials for several traits, such as diameter and wood basic density, suggesting that for this mating type our average parameter estimates are likely to be robust. In open-pollinated trials, average heritabilities for growth traits (e.g., ̄h2op= 0.26 for diameter) were generally lower than those for wood property traits (e.g., ̄h2op = 0.51 for basic density). However, this trend was reversed in average additive genetic coefficients of variation (e.g., CVa=13.3% for diameter and 4.5% for basic density). Inter-age genetic correlations for stem diameter ranged from 0.68 to 1.00 but were not available for important wood property traits (e.g., cellulose content and pulp yield). For most traits, inter-site genetic correlations were, on average, positive and strong (e.g., ̄rg =0.70 for diameter) but some weak individual estimates were observed. The average genetic correlation between diameter and basic density was –0.27. Few estimates of genetic correlations for pulp yield (or cellulose content) with diameter and basic density were available. Estimates of genetic parameters for solidwood traits were also uncommon in the literature.