Selección de familias e individuos en prueba de progenie de Eucalyptus grandis W. Hill Miden en la Estación Experimental Bernardo Rosengurtt (E.E.B.R)

This study refers to a progeny test of Eucalyptus grandis W. Hill ex Maiden at the Bernardo Rosengurtt Experimental Station (E.E.B.R.). The objectives include evaluating the growth and performance of the species to identify superior genotypes in terms of productivity and quality. Dendrometric variables such as diameter at breast height (DBH), total height, and individual real volume were measured. The genus Eucalyptus, with approximately 600 species, is fundamental to commercial forestry worldwide. In Uruguay, Eucalyptus grandis is one of the most widely used species due to its rapid growth and high-quality wood. The original trial was conducted with 119 families (from six seed sources) under a randomized complete block design (RCBD), consisting of nine blocks and five individuals per family/block. Due to high mortality, a set of criteria was established in this study to determine the inclusion of blocks and individuals in the genetic analysis of the trial. The results showed significant genetic variability among the evaluated families, allowing for the selection of superior genotypes. The total volume for the 2.7 ha of the blocks considered in the trial was 1,868.59 m³. Additionally, the volume per hectare reached 692.07 m³, representing a 73.73% increase compared to the last recorded evaluation in 2004. The assumed additive genetic variance was generally low in the trial, representing only 6.93% of the average phenotypic value of the individuals. This was associated with limitations imposed by high mortality and adverse environmental conditions. However, the trial demonstrated adequate precision in estimating genetic parameters. Families 79, 97, and 72 stood out in terms of volume, presenting the highest phenotypic values, with 1.765, 1.725, and 1.679 m³ tree⁻¹, respectively. In contrast, families 64, 77, and 15 exhibited the lowest volume values, with 1.191, 1.189, and 1.186 m³ tree⁻¹, respectively. The best families and individuals were identified to contribute to forest genetic improvement in Uruguay, proposing selection and genetic management strategies to maximize genetic gains and conserve diversity.