Genetic parameters for growth traits in the early stages of the pequi tree

Abstract

Genetic parameters estimated through statistical-genetic designs considering population and progeny effects are lacking for the pequi tree (Caryocar brasiliense Camb.). The aim of this study was to estimate genetic parameters and evaluate the efficiency of selection based on growth traits in the early stages. The experiment was carried out in Carbonita, Minas Gerais, Brazil, on January of 2005, using a randomized block design with 31 progenies, six replications and five plants per plot. From 2005 to 2008 the following traits were evaluated: plant height (in 2005; 2006; 2007 and 2008), stem diameter at ground level (in 2006; 2007; 2008) and crown diameter (in 2008). Estimates for narrow-sense heritability at the individual level varied from 0.15 to 0.50. The genetic and phenotypic correlations between characteristics in the different years were positive and generally highly significant. Estimates of the selection efficiency, obtained using the Hamblin and Zimmermann Expression, ranged from medium to high for all traits. It was concluded that under the premise of a significant correlation between these traits and fruit production, selection for fruit production based on growth traits could be started at an early stage.