Desempenho de famílias e clones de Eucalyptus spp

Abstract

The eucalyptus culture is vital for Brazilian agribusiness. Due to their importance, eucalyptus breeding programs are consolidated in the national territory. One of the most efficient methods for obtaining superior genotypes is the evaluation of families in progeny tests with subsequent selection and cloning of superior individuals. Thus, the aim of this study were to evaluate the performance of families and clones of Eucalyptus spp.; to estimate genetic parameters associated with plant height and circumference at breast height; to evaluate the correspondence of the clones with the selected progenies; and to obtain estimates of general and specific parenting capabilities. At the age of four, 130 families of German brothers and nine other witnesses were evaluated. The best individuals in the progeny test were cloned and advanced to the clonal tests (CT). In the clonal test called TC 60, 372 clones were evaluated and in the called TC 66, 453 were evaluated. Both clonal tests were evaluated at four and six years of age. The three experiments were conducted by the company Plantar S / A., being the progeny test and TC 60 implanted in the city of Curvelo / MG, and TC 66 in Itacambira / MG. The design used was complete randomized blocks, with 28 repetitions for the progeny test and 20 repetitions for the CT. The plots consisted of a single tree, with a 3 x 2 meter spacing for all experiments. Plant height (ALT) and breast height circumference (CAP) were evaluated. Data were analyzed using a mixed model approach with the aid of the R software. The genetic variance components of individuals within families and clones were estimated, heritabilities, selective accuracy (rgg'), coefficients of variation (CV), the CGC and CEC, and the average BLUPs of families and clones. The rgg' and CV estimates obtained show good experimental precision. The components of genetic variance were significant. The CGC estimates show the superiority of the parents 3673, 2469, 3336, 1288, and the inferiority of the parents 1187, 3192 and 3016. Nine families presented significant CPB estimates for ALT and CAP. The rankings of the clones at four and six years of age were little coincident. The magnitudes of the BLUPs mean that it is possible to select superior clones for plant height and circumference at breast height.