Melhoramento de características radiculares em Eucalyptus

Abstract

Brazil has 8.1 million hectares dedicated to eucalyptus cultivation, establishing itself as the main forestry crop in the country. The wood produced from eucalyptus plantations is used for the paper and pulp industries, charcoal, wood panels, laminated flooring, sawn timber, cosmetics, and pharmaceuticals. In recent years, the intensification of climate change has been causing serious harmful alterations in soil and climate conditions worldwide, primarily resulting in changes in precipitation patterns and increased temperatures, expanding eucalyptus planting regions that are susceptible to water stress and posing a new challenge for forestry. Thus, the advancement of research to understand which plant mechanisms can be used for resilience to water stress becomes essential. Roots are essential for mechanisms of drought stress tolerance, as a robust root system can confer greater ability to capture water from the soil. The present study aimed to understand the feasibility of aeroponics as a suitable early screening method for identifying genotypes with superior root systems. Two clonal trials and one progeny trial were conducted, followed by the estimation of statistical and genetic parameters for root development traits using mixed linear models. The results reveal that there was a high mean heritability for progenies and clones, and moderate to high individual heritabilities in the progeny trial, indicating variability for individual selection in the progeny trial, with good capacity for estimating the combining ability of the parents, as well as a reliable estimation of the genetic values of the clones in the clonal trial. In this way, aeroponics has proven to be a viable phenotyping method for the identification and selection of superior clones and progenies for the root system, and it can be a practical and reliable tool for early phenotyping and selection of superior genotypes.