In genetic breeding of forest species, a base population or pre-selected higher individuals have a fundamental importance to program maintenance due to their better origins and large genetic basis, which continuously propitiates gains. The aim of this study was to verify the variability level in two Eucalyptus grandis nucleus populations. Thus, 39 individuals were evaluated - 19 in population 1, and 20 in population 2. Fourteen microsatellite primers were measured, identified and analyzed using GeneScan and Genotyper software through an ABI Prism 3100 automatic sequencer. The number of alleles in each primer varied between 5 and 15 in population 1, and from 8 to 18 in population 2. Heterozygosity was higher in population 2 - 0.869, versus 0.843 in population 1. Mean genetic distance among individuals was 0.6220 in population 1 and 0.6112 in population 2. After individual molecular characterization, a database was compiled to allow the control of these improvement programs in different selection cycles based on population genetic parameters.
nucleus populations; Eucalyptus; improvement; microsatellites
