Longitudinal data improves selection of drought-tolerant Eucalyptus germplasm
摘要
In Brazil, nearly half of the country’s eucalyptus plantations are located in regions where seasonal dry periods lasting three to five months bring monthly rainfall below 50 mm. Thus, the main goal of this study was to evaluate the potential benefits of incorporating multi-year and multi-environmental data, as well as to investigate the impact of modeling different covariance structures on the selection of drought-tolerant families, and thus compare the results with the standard analysis model framework used in forest breeding. For this purpose, we evaluated the diameter at breast height (DBH, cm) in 232 Eucalyptus families and six commercial clones, installed in different experimental trials distributed in three distinct locations in Brazil. Three measurements were performed at 18, 30, and 42 months after planting. Finally, we identified promising families for cultivation under drought conditions. Our results show that spatial row–column corrections improved model fit (as indicated by lower AIC values) in single-environment analyses and were therefore adopted for subsequent multi-environment and multi-age analyses. Among the selected best-fitting models, the heterogeneous compound symmetry covariance structure effectively accommodated the data complexity for predicting interaction effects, while diagonal