Sistema reprodutivo e parâmetros genéticos de progênies de Parkia multijuga Benth em plantio de produção na Amazônia Central

Abstract

Parkia multijuga is one of the native tree species of the Amazon rainforest with potential silvicultural characteristics for forest plantation. The selection of superior genotypes in progeny tests is a promising alternative for obtaining seeds to produce seedlings for new plantations. The objectives of this work were to characterize the reproductive system and to estimate phenotypic variability of the progenies of the P. multijuga to identify superior genotypes. The experiment was installed at the Experimental Farm of UFAM, Manaus. For the study of the reproductive system, 14 plants of 14 progenies were sampled, totaling 182 plants. Plant material (leaves) was collected from 13 mother plants and 182 plants. We extracted plant DNA and analyzed it with 7 microsatellite loci. The estimates of genetic parameters were obtained from 14 P. multijuga progenies in a randomized complete block design. The monitoring of the plants during two years allowed obtaining estimates of genetic parameters such as heritability, accuracy and selection gain for the silvicultural characteristics height, stem diameter, crown area and absolute and relative growth rate. The analyzes were performed using the REML/BLUP model in the statistical program SELEGEM. The estimates of the cross-system parameters obtained in this study indicate that the P. multijuga is an allogama species. The 13 progenies studied were mainly represented by half-siblings, but the crosses were not random due to the occurrence of some correlated mating, resulting in some complete siblings within the progenies. The high values of accuracy indicate good experimental accuracy and show that the selection of the superior genotypes can be safely performed for absolute growth rate and relative growth rate, stem diameter and crown area evaluated in P. multijuga genotypes. The period between 28 and 34 months is the most appropriate for a single evaluation to plant height, stem diameter and crown area of the P. multijuga under the planting conditions of Central Amazonia.