GENETIC PARAMETERS OF Eucalyptus spp. CLONES IN NORTHEASTERN BRAZIL

Abstract

Brazil is the largest charcoal producers in the world, with the main centers of charcoal consumption located in the states of Minas Gerais, Mato Grosso do Sul, Espírito Santo, Maranhão, and Pará. Planting of Eucalyptus in the northern and northeastern states of Brazil is relatively new and is limited the lack of genetic materials adapted to the region’s high temperatures and severe, prolonged periods of drought. The objective of this study was to assess the genetic parameters and variability and determine the genotype x environment interaction for drought tolerance in Eucalyptus clonal tests established in two environments in the municipality of Grajaú, Maranhão State, Brazil. The tests were planted in January 2011 in clayey and sandy soils in a randomized complete block design with 130 clones, one plant per plot, and 20 replicates. The studied clones showed high genetic variability for drought tolerance, with coefficients of relative variance () consistently greater than 0.8 for DBH and volume. This indicates high levels of genetic control and less influence of environmental factors on the phenotype, which allows for selection and obtaining gains through breeding. Heritability estimates were high for growth traits, with average clone heritabilities () greater than 0.85, as well as acuracies () above 0.9 for DBH and volume in clone selection. There was a simple interaction between genotype x environment for the clones under the two different soil conditions.

Classifying coefficients of genetic variation and heritability for Eucalyptus spp.

“…Estimates of genetic parameters obtained in clonal tests of Eucalyptus spp. showed that variations in broad sense genetic heritability depend on growth traits, which is consistent to what was observed in this article; however, the general averages of these values were similar among them and close to 0.5 for diameter, height and volume (Furlan et al 2020).…”

Evaluation of genetic parameters and clonal selection of Eucalyptus in the Cerrado region

“…Average heritabilities (h 2 m ) between 0.22 to 0.64 were observed for dendrometric traits in various Eucalyptus sp. clones (Nunes et al 2016, Santos et al 2015, Tambarussi et al 2017, Furlan et al 2020.…”