Abstract We evaluated the genetic diversity, coancestry and heritability of an E. benthamii trial. The 115 individuals were genotyped (13 SSR) and had their height and diameter at breast height (dbh) measured. Heritability was estimated using the RR-BLUP and the pairwise kinship coefficient method. An average of nine alleles per locus was observed. The expected heterozygosity (0.655) was similar to the observed heterozygosity, with the estimated inbreeding (0.02) being low. The group coancestry (0.051) demonstrates that the trees are related to some degree. The trees were clustered in five groups using the Evanno’s method. The average kinship within each group ranges from 0.042 to 0.082. The heritability estimated by RR-BLUP was low. The heritability estimated using the kinship coefficients is moderate, reaching estimated genetic gains of 14% for dbh. After knowing how genetic groups are distributed within the population, strategies for collecting, conserving, and using these germplasm resources can be performed.

Resumo: O objetivo deste trabalho foi avaliar a variabilidade genética de Araucaria cunninghamii, em teste de procedência, e estimar ganhos genéticos para a produção de sua madeira, com base em diferentes intensidades de seleção. O experimento foi estabelecido em Luís Antônio, no estado de São Paulo, Brasil, com sementes de polinização aberta coletadas em Queensland, Austrália. O delineamento experimental utilizado foi o de blocos ao acaso, com seis repetições e quatro plantas por parcela. O diâmetro à altura do peito (DBH), a forma do fuste e a sobrevivência foram medidos 29 anos após o plantio. Diferenças significativas foram detectadas entre as procedências. O coeficiente de variação genotípica foi alto (60%) para DBH. Os valores médios de DBH e forma do fuste foram de 23,21 cm e 4,50, respectivamente. As procedências Langkelly Creek, Brooweena L.A., Yarraman e St. Agnes apresentaram melhor desempenho em DBH, e Imbil Seed Orchard, Brooweena L.A., St. Agnes, St. John e Yarraman, em forma do fuste. Os ganhos estimados com a seleção variaram de 0,5 a 24,8%, para DBH, e de 0,9 a 3,5%, para forma do fuste.

Abstract: The objective of this work was to assess the genetic variability of Araucaria cunninghamii in a provenance test and to estimate the genetic gains in its wood production, based on different selection intensities. The trial was established in Luís Antônio, in the state of São Paulo, Brazil, using open-pollinated seed from Queensland, Australia. The experimental design used was a randomized complete block with six replicates, and four plants per plot. Diameter at breast height (DBH), stem form, and survival were measured at 29 years after planting. Significant differences were detected among provenances. The coefficient of genotypic variation between provenances was high (60%) for DBH and stem form. The mean values for DBH and stem form were 23.21 cm and 4.50, respectively. The provenances Langkelly Creek, Brooweena L.A., Yarraman, and St. Agnes showed the best performance for DBH, and Imbil Seed Orchard, Brooweena L.A, St. Agnes, St. John, and Yarraman, for stem form. Genetic gains ranged from 0.5 to 24.8% for DBH, and from 0.9 to 3.5% for stem form.

Abstract Cordia trichotoma is a Brazilian species that has been studied for different forest systems. However, genetic breeding programs could highly improve species use. To obtain a better yield, it is essential to identify the species genotypes with superior performance. Thus, the work objective of this work was to estimate genetic divergence in two C. trichotoma progenies tests based on phenotypic traits. The experimental design adopted was the randomized blocks, one plant per plot, using 40 (area one) and 34 (area two) repetitions, using 3.0 m × 3.0 m spacing. The evaluated traits were diameter at 1.30 m above the soil (DBH-cm), total height (HT-m), collar diameter at 30 cm above the ground (DC-cm), and height of the first whorl (HFW-cm). The estimate of genetic divergence and the Tocher clustering method was performed using the REML / BLUP method. The genetic distances between the progenies in area 1 were 2.13 and 47.74 (17 and 15). In area two the genetic distances between the progenies were 3.64 (9 and 15) and 48.28 (12 and 7). The progenies formed 10 and 4 distinct groups, respectively, in area 1 and area 2). The traits that most contributed to genetic divergence were DBH-2016 (14.65%) in area one, and HT-2014 (14.32%) in area two. In sumary, the C. trichotoma progenies show high genetic divergence. Regarding breeding programs, it is recommended to cross progenies from the most divergent groups to heighten the genetic gain through the selection of more productive genotypes.

Resumen Cordia trichotoma es una especie nativa que está siendo evaluada para diferentes sistemas forestales. El hecho de que los individuos empleados en las plantaciones posean algún grado de mejoramiento genético tiene muchas ventajas; para lograr este mejoramiento es fundamental la obtención de genotipos superiores, a fin de obtener un mejor rendimiento del producto final. El objetivo del presente estudio fue estimar la divergencia genética de progenies de C. trichotoma en dos diferentes condiciones de textura de suelo, por medio de caracteres fenotípicos. El diseño experimental fue bloques completos al azar, un árbol por parcela con 40 (área 1) y 34 (área 2) repeticiones, con espaciamiento de 3,0 m × 3,0 m. Los caracteres evaluados fueron: diámetro a altura del pecho, altura total de plantas, diámetro de cuello y altura del primer verticilo. Para estimar la divergencia genética y el agrupamiento de Tocher fue utilizado el método REML/BLUP. Las distancias entre las progenies en el área 1 fueron de 2,13 y 47,74 (17 y 15), en el área 2 las distancias entre las progenies fueron de 3,64 (9 y 15) y 48,28 (12 y 7). Las progenies formaron diez y cuatro grupos distintos (área 1 y área 2). Los caracteres que más contribuyeron para divergencia genética fueron diámetro a la altura del pecho-2016 (14,65%) área 1, y altura total de plantas-2014 (14,32%) área 2. Las progenies de C. trichotoma presentaron alta divergencia genética. En programas de mejoramiento, se recomienda el cruzamiento entre progenies de los grupos más divergentes para priorizar la ganancia con selección de los genotipos más productivos.