GANHOS GENÉTICOS VIESADOS PELO SISTEMA MISTO DE REPRODUÇÃO EM Eucalyptus spp

Abstract

Estimates of genetic variance and coefficients of heritability are fundamental in to breeding programsto quantify the gains that will be obtained through selection. In this study, we compare eucalyptus species with differente reproductive systems to assess the overestimation of genetic gains the breeding system of the species is disregarded. Five provenances of Eucalyptus camaldulensis (predominantly allogamous) and seven provenances of Eucalyptus pellita (predominantly mixed-mating) were tested. The experiments were installed on field conditions in 2014, a complete randomized block design, with ten replicates, and seven plants per plot for E. camaldulensis and six plants per plot for E. pellita. At two years of age, we measured diameter at breast height (DBH), height (H), and volume (VOL). The mean heritability (ˆ 2 hm) varied between 0.96 (DBH), 0.93 (VOL), and 0.90 (H) for E. pellita, and between 0.49 (DBH), 0.48 (H), and 0.32 (VOL) for E. camaldulensis. Due to the observed overestimation of genetic gains, losses ranged from 56.81% to 75.60%. The genotypic and phenotypic correlations were high and statiscally significant for all characteristics, indicating the possibility of performing indirect selection. These results show that incorporating reproductive system data into estimates of genetic parameters increases accuracy and directs the breeder toward the conservation and production of non-biased gains in subsequent breeding population cycles.