GENETIC PARAMETERS AND CORRELATION BETWEEN GROWTH TRAITS IN YOUNG PROGENIES OF Corymbia torelliana (F.Muell.) KD Hill and LAS Johnson

Abstract

Background: Corymbia torelliana is a promising alternative for the forestry sector due to its rapid growth, resistance, and high-quality wood for charcoal and biomass production. However, there is limited information regarding its genetic performance under Brazilian conditions. This study aimed to estimate genetic parameters and evaluate correlations between growth traits in young half-sib progenies. The experiment was conducted in Lavras, MG, with 28 progenies evaluated in a randomized complete block design, with eight replications and five plants per plot. Height (H) and diameter at breast height (DBH) were measured at 12, 18, and 24 months, and genetic estimates were obtained using the REML/BLUP method, including analyses of genotypic and phenotypic correlations.
Results: Narrow-sense heritabilities showed moderate magnitude (0.18 to 0.22), as well as progeny selection accuracy (0.64 to 0.68). Individual genetic variation coefficients ranged from 8.3% to 12.8%, indicating genetic variability among individuals. The environmental effect among plots was significant, with a determination coefficient above 0.10. Average DBH ranged from 2.4 to 5.3 cm with increasing age, and mean height reached 2.91 m at 12 months. High genetic and phenotypic correlations suggest potential for simultaneous selection, although indirect selection accuracy was lower than direct selection.
Conclusion: The results confirm the genetic potential of C. torelliana for selective gains, particularly in DBH at 24 months. The study highlights the importance of improving management practices and selection strategies to mitigate environmental effects and enhance the accuracy of genetic estimates.