ADEQUAÇÃO DE METODOLOGIA PARA ENVELHECIMENTO ACELERADO E ESTUDOS DE REPETIBILIDADE E DISSIMILARIDADE GENÉTICA EM SEMENTES DE Mimosa scabrella BENTH.

ABSTRACT Mimosa scabrella Benth., commonly known as bracatinga, is a fast-growing forest species with several applications. Seed quality is crucial for the success of reforestation, encompassing both physiological and genetic aspects. The accelerated aging test is an effective tool to assess seed vigor, allowing the differentiation of seed lots. Genetic quality is essential in breeding programs, where larger seeds are presumed to have greater reserves and, consequently, a higher chance of survival under stress. The repeatability coefficient is used to ensure the recurrence of desirable traits over time, while genetic dissimilarity guarantees variability within the available genetic material, seeking greater heterotic effect. This study aimed to adapt the accelerated aging test for seeds from 10 M. scabrella mother trees, determine the repeatability coefficient for four biometric seed traits, and assess the genetic dissimilarity among the mother trees. Seeds were collected from a population in Curitibanos, SC. For the accelerated aging test, five treatments (0, 24, 48, 72, and 96 hours) at 40°C were applied. Using the GENES program, the repeatability coefficient (r), determination coefficient (R²), and genetic dissimilarity among mother trees were evaluated. The accelerated aging test, applied at 40°C for 72 hours, proved suitable for differentiating mother trees in terms of seed vigor. The repeatability coefficient was high for weight and longitudinal diameter, and intermediate for equatorial diameter and thickness. To ensure 95% determination, 18 seed measurements are required for all traits. Mother trees 3 and 7 showed the greatest divergence, and the methodology (Mahalanobis distance) allowed the formation of two slightly dissimilar groups, indicating low genetic variability in the population. Keywords: Bracatinga. Vigor. Genetic improvement. Genetic divergence.