Identifying deployment zones for Eucalyptus camaldulensis x E. globulus and x E. grandis hybrids using factor analytic modelling of genotype by environment interaction

In this study we apply factor analytic methods to the analysis of diameter at breast height (DBH) at 3 years for 22 trials of 892 clones from four E. camaldulensis x E. globulus and six E. camaldulensis x E. grandis families established throughout Australia (Queensland, New South Wales, Victoria, Tasmania and Western Australia). Three factors were sufficient to describe the genetic variation in the data set and, on average, described 86% of the genetic variance within a trial. Estimated broad-sense heritability ranged from 0.05 to 0.85, and genetic correlation estimates between pairs of trials ranged from 0.09 to 0.99. Two-dimensional plots of factor loadings and cluster analysis of the estimated genetic correlation matrix indicated that the trials formed three groups that represent potential zones for deployment to maximise genetic gain. However, there was no geographic pattern in the distribution of the trials within these groups; further research is required to develop predictive models of the patterns in GxE for the germplasm and identify genotypes that are superior in each deployment zone.