Avaliação genética de progênies de cedro australiano

Abstract

The objectives of this paper were to estimate the genetic parameters of Austrailian Cedar progenies at distinct ages; to study the ideal age for selection: and to verify the type of interaction present. Sixty-six progenies derived from 12 locations in Australia were used. The experiment was implanted in a completely randomized blocks design, with three replicates, and 16 plants per plot. The progenies were evaluated regarding diameter at breast height (DBH) and height (HGT), at ages of 31, 54, 74 and 99 months. The genetic parameters the genotypic values were estimated by the REML/BLUP method using the Selegen software. Phenotypic and genotypic correlations were also estimated for all ages and between traits, coincidence indexes, interactions, selection gain and realized herdability. The genotype x age interaction was decomposed into simple and complex. Herdability was low for DBH and HGT. There were significant differences between the progenies at the distinct ages evaluated, with predominance of interaction of the simple type in three pairs of ages (31/54, 31/74 and 31/99) for both traits. The correlations were high and positive for all traits, and in distinct ages, demonstrating selection efficiency from 31 months and higher. The highest coincidence percentage obtained was between 74 and 99 months for DBH and HGT.