Growth and wood quality traits in the genetic selection of potential Eucalyptus dunnii Maiden clones for pulp production

Abstract

The Eucalyptus dunnii Maiden is an outstanding species for growth and wood quality traits. However, important wood quality traits for pulp and paper production are disregarded in tree breeding. Thus, the present study aimed to estimate the genetic parameters of growth and wood quality traits and establish selection criteria to increase pulp production in E. dunnii clones in different environments. The clonal test of E. dunnii was established in a randomized complete block design with a single-tree-plot in three environments. Growth values were obtained from 3.5-year-old trees. Wood quality values were measured by near-infrared spectroscopy. The phenotype index mean annual pulp increment was calculated using the values of mean annual increment, basic wood density, and pulp yield. A mixed linear model via REML/BLUP was used to obtain the genetic parameters and the rank of genotypic values considering several environments. Results revealed genetic variance for wood quality traits in E. dunnii. Klason Lignin presented high broad-sense heritability; basic wood density, pulp yield, mean annual pulp increment, and mean annual volume increment had moderate broad-sense heritability; and total extractives and diameter at breast height showed low broad-sense heritability. All traits presented high to very high selective accuracy. Simple clones x environments interactions were observed for the tested environments. An elite clone of E. dunnii were better than the commercial control clone for annual pulp increment mean. Therefore, the selection based on growth and wood quality traits is essential for pulp and paper sector.