Genetic Diversity of an Important Native Species of Atlantic Rainforest in Natural Remnants and Forest Restorations Using Genotyping-By-Sequencing (GBS)

Casearia sylvestris is a potentially medicinal species widely distributed through Latin America and Caribbean. It belongs to the Salicaceae family as well Salix purpurea and Populus trichocarpa, species with complete sequenced genome in nowadays. C. sylvestris has been used in forest restoration projects in Brazil because it is a pioneer species with fast establishment, but these forest restorations were not implemented using any information about genetic diversity. The aim of this study was understanding the genetic diversity and genetic structure in two C. sylvestris natural populations and two forest restorations. We performed GBS in 24 individuals each population and we built loci de novo using Stacks. At the next step, we analyzed the genetic diversity and structure using heterozygosities (H_O and H_E), allelic richness (A_R), fixation index (F_IS), DAPC and others. All these analyses were performed using the R packages: adegenet and hierfstat. Based on results it is possible to understand that there are no differences among the genetic diversity parameters in natural forests and restorations (H_O = 0.1757 ± 0.0063, H_E = 0.2433 ± 0.0070, A_R = 1.82 ± 0.02, F_IS = 0.2278 ± 0.083). Moreover, there is not inter-population structure (F_ST = 0.00). Therefore, we suggest that may have gene flow among forest restorations and natural forest remnants because C. sylvestris is widely distributed and easy to establish in many environments. This situation can contribute with the planing of strategies of conservation for important species as C. sylvestris.