Variação genética em caracteres de crescimento em progênies de Dipteryx alata Vog

Abstract

The aim of this work was to estimate the genetic variation among and within Dipteryx alata progenies to propose a selective logging to establish a seedling seed orchard with variability and genetic quality. The progeny test was established in December 1986 at Pederneiras Experimental Station, São Paulo Forestry Institute, following a randomised block design with 25 progenies, five replications, five plants per plot and 3 x 3 m spacing. The test was measured 25 years after planting for the traits: total height, diameter at breast height (DBH), wood volume, forking and survival. Deviance analyses were performed to determine the genetic variation among and within progenies for growth traits. The variance components and genetic parameters estimates were obtained by REML/BLUP methods (Restricted maximum likelihood/Best linear unbiased prediction) using the Selegen software. Based on likelihood ratio test, no significant differences between and within Dipteryx alata progenies were detected to growth traits, only for forking there was a significant difference in relation to progeny and plot. The individual narrow sense heritability was very low for most of the traits, except for the height (0.27), which in turn, had the highest accuracy. It is recommended to perform a selective logging to eliminate low production trees and increase the genetic basis of this population from the introduction of other genotypes.