Predicted parental genetic values of 363 half-sib Eucalyptus grandis and 245 half-sib E. urophylla progenies were evaluated for selection to produce interspecific hybrids in controlled crosses in a circulating diallel. The essays were conducted in Guanhães, Minas Gerais, in a complete randomized block design in five replications, row plots of six E. urophylla and eight E. grandis plants in 3.0 x 2.0 m spacing. The genetic parameters were estimated by mixed models using the REML / BLUP (restricted maximum likelihood / best linear unbiased prediction) procedure for diameter at breast height (DBH), total height (TH) and individual volume (VOL) traits. The genetic values were only predicted for diameter at breast height (DBH), to which the selection was performed. The estimated heritability values in the restricted sense for Eucalyptus urophylla were 0.2785 and for accuracy 61%, and 0.2247 and 53% in Eucalyptus grandis, respectively. Selection of 100 parents of each species individually will provide genetic gains of 20.6 % in Eucalyptus urophylla and of 16.4 % in Eucalyptus grandis. A genetic gain for diameter at breast height around 35.0% can be obtained by crosses among the first 10 selected individuals of each species and carriers of the greatest genetic divergences.
Forest improvement; genetic parameters; mixed models
