Genetic analysis of half-sib progenies of Theobroma grandiflorum

Abstract

The cupuaçuzeiro (Theobroma grandiflorum), species native from the Amazon region, has been domesticated presenting a broad genetic variability, and thus favorable conditions for establishing of strategies to breeding and genetic conservation. The aim of this work was to evaluate 36 half-sib progenies of Theobroma grandiflorum obtained from a stratified mass selection in farmers areas based on primary components of yield. The experiment for selection of elite progenies was set up in a randomized complete block design with three replications and four plants per plot. The fruit traits (length and width, in cm) and components of production (average weight of fruit/plant; average weight of pulp with seeds/plant and average weight of pulp/plant, in g) were evaluated. The data were analyzed through the methodology of REML/BLUP using the Selegen software. Analysis of grouping was performed using the matrix of genetic euclidean distances and Mahalanobis. The experimental population allowed the selection of superior parents for formation of base population to be used in the genetic improvement of cupuaçu. Among the 36 analyzed lineages only the genotypes 9, 10 and 18 showed genetic divergence and they can be recommended with some lineage of group 1 that demonstrates agronomic superiority to form base population of experimental clones with high genetic dissimilarity.

doi: 10.4336/2011.pfb.31.66.123