Produtividade, qualidade da madeira e interação genótipo x ambiente do Eucalyptus dunnii Maiden no Sul do Brasil

Abstract

Eucalyptus dunni has been showing a high value for commercial plantation in the South of Brazil, mainly because of high frost tolerance and high wood quality presents in its genotype. Some results have shown wood density of 500 kg m-3 and cellulose yield of 52% in E. dunni. The main objective of this study was evaluate genotype x environment interaction on growth and wood quality at different weather conditions characteristics in the state of Rio Grande do Sul. Genetics parameters were studied and correlation among them was analyzed establishing a linear correlation to study the relationship between growth and wood quality via Restricted Maximum Likelihood and Best Linear Unbiased Predictor (REML/BLUP) and to selection of individuals in families of half siblings and clones of E dunnii. Data from an experimental network of the company CMPC Celulose Riograndense were used, and the design was randomized blocks in a factorial scheme with 72 families of half siblings and 37 clones of E. dunnii in common between the environments and 20 replicates, with one tree per plot. The difference between treatments was evaluated via deviance analysis (ANADEV). Through deviance analysis (ANADEV) it was possible to verify the existence of significant differences for the treatment effect (progenies and clones), demonstrating that there are significant differences among the genotypes for selection. It was possible to predict the genetic gains with the selection made between and within the families for the mean annual increment (MAI) expressed in m³ ha-1 year-1. Growth features showed lower heritability, while wood quality characters showed moderate heritability. The results indicated a higher correlation among DBH x Db and growth features. In clones of E. dunnii, similar results were also found among DBH x Db and wood quality, suggesting that selection taking account DBH x DB provide direct gains for individual volume and mean annual increment (MAI) and also wood quality. The improvements obtained in relation to the general mean of the clones and the best control estimated by the Harmonic Mean of the Relative Performance of Genetic Values (MHPRVG) were very similar to the gains genotypic average (u + g + gem).