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ResumoA produção volumétrica tem sido prioridade nos programas de melhoramento florestal. No entanto, é necessário que a qualidade da madeira seja considerada, para que o fornecimento da matéria prima permita aumentar a eficiência e o rendimento industrial. Dessa forma, o objetivo deste trabalho foi estimar parâ-metros genéticos, correlações genéticas e ganhos com a seleção para caracteres de crescimento (diâme-tro), espessura de casca e densidade básica da madeira de Eucalyptus urophylla. Para tanto, utilizou-se discos de madeira retirados no DAP e metade da altura comercial, provenientes de árvores desbastadas em um teste de progênies de polinização aberta com 33 genótipos e duas procedências (Rio Claro-SP e Três Lagoas-MS), localizado em Selvíria-MS. Os parâmetros genéticos foram obtidos com base no procedimento REML/BLUP. O melhor desempenho para crescimento foi verificado para Rio Claro. Não foram detectadas diferenças genéticas para densidade da madeira entre as procedências. A procedência de Três Lagoas apresentou coeficiente de variação genética > 14% (diâmetro) e forte controle genético (herdabilidade > 0,6 e acurácia > 78%). Para qualidade da madeira, Rio Claro sobressaiu-se nas estimativas de herdabilidade (> 0,6 -DBM e ECD), alcançando acurácia superior a 79%. Foram encontrados resultados contrastantes para as correlações genéticas entre as duas procedências. Para a obtenção de materiais genéticos com maior densidade da madeira, a seleção para DBM é vantajosa. Palavras-chave: melhoramento florestal, qualidade da madeira, REML/BLUP. AbstractVolumetric production has been a priority in forest breeding programs. However, it is necessary to consider wood quality for the raw material supply that increases efficiency and yield. Thus, the aim of this study was to estimate genetic parameters, genitic correlations and selection gains for growth traits (diameter), bark thickness and basic density of wood in progênies of Eucalyptus urophylla. For this, we used wood discs removed at DHB and half the commercial height, from trees thinned in an open pollination progeny with 33 genotypes and two provenances (Rio Claro-SP and Três Lagoas-MS), located in Selvíria-MS. Estimates of genetic parameters were obtained using the REML/BLUP method. The best performance for growth was found in the Rio Claro provenance. Genetic differences in wood density between the provenances were not detected. The provenance of Três Lagoas showed a coefficient of genetic variation > 14% (diameter) and strong genetic control (heritability > 0.6 and accuracy > 78%). For wood quality, Rio Claro stood out in the estimates of heritability (> 0.6 -DBM and ECD), achieving a higher accuracy of 79%. Contrasting results were found for the genetic correlation between the two sources. For obtaining genetic materials with higher density wood, the selection for DBM is advantageous.

One of the determinant factors in the success of breeding pro­grams that aim to select genotypes for different geographical regions is understanding the interaction between genotypes and environments (GxE). The objectives of this study were to evaluate GxE interaction, stability, and adaptability, and deter­mine the need for environmental stratification of open pollina­ted progenies of Eucalyptus urophylla. Five progeny tests were established in study areas with different environmental condi­tions in southeast and mid-west Brazil. We used a complete randomized block experimental design with 138 to 167 proge­nies, and variations in the numbers of replicates and plants per plot. The trait measured was diameter at breast height (DBH) at two years of age and the AMMI method was used to determine patterns of GxE interaction. Significant effects were detected for genotypes, environments, and for GxE interaction. The effect of environment was responsible for the greatest propor­tion of the phenotypic variation, followed by the effect of genotypes and GxE interaction. Some progenies with greater productivity and stability were identified, although stability is not associated with productivity. The stratification of the selec­tion in three specific environments is necessary due to the occurrence of a complex GxE interaction.

Our aim was to verify the effect on gain and genetic diversity through the restriction of the number of trees per family in selection, in order to compose an elite population of Eucalyptus urophylla in two trials under distinct management levels.We studied 166 open-pollinated families of E. urophylla in Anhembi, Sao Paulo State, Brazil under commercial practices, and the same families in Selvíria, Mato Grosso do Sul State, Brazil under lower management level (mainly no mineral fertilization). Mortality, height and diameter at breast height (DBH) were measured. DBH was analyzed by the REML/BLUP to select the best 25 trees, with four levels of tree restriction per family (no restriction; 1; 2 and 3 per family). We evaluated heritability; genetic gain and effective size of number of total and private alleles; observed and expected heterozygosity; coancestry and fixation index. A large difference in survival (48 and 83 %) and productivity (MAI of 26 and 44 m 3 ha -1 y -1 ) was observed between trials due to the different levels of management applied. The highest restriction in number of individuals per family caused a small decrease in gain, corresponding to 7 % in the more productive trial and 3 % in the less productive one. Observed and expected heterozygosity, coancestry and fixation index were not significantly (lower than 5 %) affected by the restriction in both sites. The restriction of one tree per family allowed different alleles to be kept in the selected population and higher effective population size in order to insure variation for the next generations. Maintenance of genetic diversity in Eucalyptus urophylla S. T. Blake populations with restriction of the number of trees per family

A exploração inadequada de madeiras nativas têm provocado à redução de populações naturais, como foi o caso da Myracrodruon urundeuva. Os objetivos deste trabalho foram estimar parâmetros genéticos para caracteres silviculturais, em um teste de progênies de M. urundeuva, em sistema de plantio multi-espécie e avaliar o potencial para conservação ex situ e transformação em um pomar de sementes por mudas. O experimento foi instalado em Selvíria, MS, no delineamento de blocos casualizados, com 30 progênies, 14 repetições e uma planta por parcela. Os caracteres foram avaliados aos quatro e nove anos de idade e as estimativas dos parâmetros genéticos foram obtidas pelo procedimento REML/BLUP. A seleção para o diâmetro a altura do peito foi baseada na seleção combinada do índice multi-efeitos e nos valores genéticos aditivos individuais. Foram obtidas estimativas adequadas de variação genética (> 12%), herdabilidade da média de progênies (ĥ m 2 > 0,35) e acurácia (r aa > 58%). A estratégia sem restrição dos 180 melhores indivíduos proporcionou o maior ganho de seleção (7,48%). A diversidade genética (67%) e tamanho efetivo (≈ 60) foram semelhantes a estratégia com restrição de indivíduos e progênies. Em função disso, a estratégia sem restrição pareceu ser mais adequada. Assim, existe variabilidade genética no teste de progênies de M. urundeuva e potencial para sua transformação em um pomar de sementes por mudas. Palavras-chave: aroeira, parâmetros genéticos, REML/BLUP, teste de progênies. Genetic variability and genetic gains in progenies of Myracrodruon urundeuva Fr. All. in multi-species system ABSTRACT: Improper exploitation of native woods have led to a reduction in natural populations, as was the case of Myracrodruon urundeuva. The objectives of this study were to estimate genetic parameters for silvicultural traits in progenies test of M. urundeuva, in multi-species system and evaluate the potential for ex situ conservation and transformation into an orchard seedling seed. The experiment was installed in Selvíria-MS in a randomized block design, with 30 progenies, 14 replications and one plant per plot. The traits were evaluated at four and nine years old and estimates of genetic parameters were obtained by REML/BLUP procedure. The selection for diameter at breast height was based on the combined selection of multi-effect index and genetic values individual additives. Appropriate estimates of genetic variation were obtained (>12%), average heritability progenies (>0.35) and accuracy (>58%). The strategy without restriction of the 180 best individuals provided the highest gain selection (7.48%). Genetic diversity (67%) and effective size (≈ 60) were similar strategy with restriction of individuals and progenies. As a result, the strategy without restriction seemed to be more appropriate. Thus, there is genetic variability in the test M. urundeuva progenies and potential for its transformation into an orchard seedling seed.