Genetic variability of two provenances of African mahogany (Khaya ivorensis A. Chev) in the cerrado

Abstract

The demand for timber products, especially of noble woods, has put pressure on native forests. Thus, African mahogany (Khaya ivorensis) represents a promising alternative to meet the market of noble woods, because of its favorable technological properties for timber production. However, there is a lack of studies of tree breeding in this species, limiting the selection of superior genotypes for the production of sawn wood. This study aimed to evaluate the genetic variability, estimating genetic parameters and predicting individual breeding values in two provenances (Mateus Leme and Matosinhos) of K. ivorensis in the Brazilian cerrado (savanna) biome, aged eight years. The trial was established in randomized complete block design, two blocks and 49 plants per plot. The traits, total height (HT) and diameter at breast height (DAP). The components of variance and genetic values predicted for HT and DAP traits were estimated through the REML/BLUP procedure. The genotypic variance for the studied variables presented a low magnitude (HT = 0.34, DAP = 0.48) compared to the phenotypic variance. The heritability coefficients among families were of the order of 0.75 and 0.74 for the traits HT and DAP, respectively. The accuracy estimates for HT and DAP traits were 0.86 and 0.87, respectively. The genetic gains were considerable for the selection of superior trees of K. ivorensis for the traits HT and DBH, indicating them as promising traits in the genotypes selection.