title: Genetic Diversity and Population Structure of Varronia curassavica: A Medicinal Polyploid Species in a Threatened Ecosystem.
abstract: Varronia curassavica is an important medicinal species associated with the restinga, one of the most threatened coastal ecosystems of the Atlantic Forest. These circumstances call for studies aimed at estimating effective population size and gene flow to improve conservation efforts. Hence, the present study aimed to characterize the genetic diversity, ploidy level, and population structure of this species in different areas of restinga using microsatellites. Varronia curassavica was characterized as an autotetraploid, with high genetic variability, low divergence, and no significant fixation indices, indicating the absence of, or reduced, inbreeding and genetic drift in the study area. About 44% of the alleles occurred at low frequency in adults of all populations and 41% in the progenies evaluated. Gene flow was high, consistent with outcrossing species with high dispersal capacity (Nm = 4.87). The results showed no tendency toward isolation by distance. The estimated effective size indicates that the populations studied have the potential to ensure conservation of the species in the long term. The genetic variability and population structure of V. curassavica, as determined in this study, could form the foundation for activities directed toward the sustainable use of this resource and its conservation. Even though the restinga ecosystem has suffered dramatic reductions in area, this study provides evidence that this species is resilient to anthropogenic threats to its genetic integrity, since it is a polyploid with self-incompatibility mechanisms that contribute to maintaining high genetic diversity in an panmictic meta-population along the coast of Santa Catarina.
authors.affiliation: From the Núcleo de Pesquisa em Florestas Tropicais, Departamento de Fitotecnia, Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Rodovia Admar Gonzaga, 1346, Itacorubi, Florianópolis/SC, CEP: 88034-001, Brazil.
authors.forename: Marcia Patricia
authors.initials: MP
authors.lastname: Hoeltgebaum
authors.affiliation: From the Núcleo de Pesquisa em Florestas Tropicais, Departamento de Fitotecnia, Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Rodovia Admar Gonzaga, 1346, Itacorubi, Florianópolis/SC, CEP: 88034-001, Brazil.
authors.forename: Maurício Sedrez
authors.initials: MS
authors.lastname: Dos Reis
mesh_terms: D000483:Alleles; D001938:Brazil; D065928:Forests; D051456:Gene Flow; D005787:Gene Frequency; D040961:Genetic Drift; D014644:Genetic Variation; D005828:Genetics, Population; D007178:Inbreeding; D019684:Magnoliopsida / Q000235:genetics*; D018895:Microsatellite Repeats; D010946:Plants, Medicinal / Q000235:genetics; D011123:Polyploidy; D011156:Population Density
keywords: conservation; effective population size; gene flow; microsatellites; restinga