Estrutura genética espacial em fina-escala, diversidade genética e autocorrelação espacial de Copaifera arenicola ((Ducke) J. Costa e L.P.Queiroz) em fragmento de Mata Atlântica

Abstract

With the increasing reduction of native forests, the maintenance and survival of the tree component depends on appropriate sustainable management strategies. Thus, understanding spatial genetic structuring and intrapopulation genetic diversity is important for the management and conservation of forest genetic resources, as well as for evaluating the impacts of exploitation and fragmentation and establishing sampling strategies in natural populations. Thus, the present study aims to evaluate the ecological aspects of the ontogenetic stages of Copaifera arenicola through studies of diversity and spatial genetic structure on a fine scale in a remaining fragment of the Atlantic Forest in Rio Grande do Norte. The sampling involved 249 individuals subdivided into three life stages, Regenerating, Young and Adults in the forest fragment. The DNA obtained from leaf and stem samples was amplified by Polymerase Chain Reaction (PCR), and the products were subjected to agarose gel electrophoresis. Using 72 ISSR (Inter Simple Sequence Repetition) loci, Nei's genetic diversity and the Shannon index presented averages of 0.27 and 0.43, respectively, with high averages being identified for all growth stages according to the life history of the species. Bayesian analysis detected the presence of k = 3 for the population, confirming intrapopulation diversity. The Spatial Genetic Structure (SGS) revealed that related individuals tend to be closer together. The EGE aggregation radius for regenerants was up to approximately 15 meters, followed by complete randomness. The spatial distribution pattern was aggregated for all distance radii across life stages. It is recommended to prioritize seed collection at distances greater than a radius of approximately 36 meters, in order to minimize the degree of kinship between specimens, to minimize the degree of kinship between specimens. The population can be a genetic support for conservation programs, as individuals present a high diversity according to the species' life history. Thus, the assessment of diversity and spatial genetic structure in association with the distribution pattern are bases that will help in the establishment of conservation strategies, sustainable use and genetic improvement.