Maximizing Eucalyptus pilularis progeny selection using a parentage matrix obtained with microsatellite markers

Abstract

Eucalyptus pilularis Smith is renowned for its high-quality wood, rapid growth, and adaptability to diverse soil conditions. This study aimed to evaluate the use of the molecular kinship matrix to estimate genetic parameters for E. pilularis selection and the potential establishment of a base population. The experiment involved 13 provenances and 115 progenies, using a randomized complete block design with five replicates and linear plots consisting of five plants each. Genetic parameters for the traits diameter at breast height (DBH), total height, and volume were evaluated at five years of age using the linear mixed model. Results indicated a survival rate for the population of 73.11%, an average total height of 18.65 m, DBH of 14.28 cm, and volume of 14.57 cm³. By adjusting the kinship matrix, the estimated values of heritability and genetic coefficients of variation decreased, indicating that there would be errors in these estimates and in the genetic gains if the progenies were assumed to be half-siblings. The discrepancy in rankings derived from the conventional half-sibling matrix versus molecular kinship matrix poses a significant challenge for experts in forest species genetic improvement. Our findings indicate not only inflated estimations of genetic parameters and gains, but also disparities in rankings when accounting for true levels of relatedness among individuals based on the molecular matrix.