Avaliação e seleção de progênies de meios irmãos de guaranazeiro (Paullinia Cupana var. sorbilis (mart.) Ducke) utilizando caracteres morfo-agronômicos

Abstract

The aim of this study was to estimate the genetic parameters, variance components, genetic correlations and constructing a selection index of guarana individuals for seed production and a breeding population, among half sib progenies of guarana in Maués, Amazonas, Brazil. Thirty-six progenies were evaluated in a randomized incomplete block design with two replicates and six plants per plot. High genetic gains for precocious yield (24.5%) were obtained with the selection of individuals using the variation between and within progenies, combined by BLUP. The best individual precocious yield was 7,720 grams per plant, which is five times higher than average state yield (1,200 g). The best expectations for genetic gain are for plant height, stem diameter and precocious yield. The selection for disease resistance should be realized at the progeny level, not between individuals within progenies. The strategy of progeny selection involving all the characters proved to be most efficient with respect to the genetic gain of nearly 100%, and should be adopted in the guarana breeding program. On the other hand, the selection of individuals for seed production and composition of the breeding population must be evaluated for more four years, since the current estimates of genetic gain, varying from 1.38% to 2.58%, do not allow secure decisions.