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.

Partitioning genetic and species diversity refines our understanding of species–genetic diversity relationships

“…The ploidy level of C. gayana is unknown; however, polyploidy is rare in the Carex genus (Lipnerová, Bureš, Horová, & Šmarda, ). Genetic diversity levels found in our study and initial evidence from AFLP markers (Troncoso et al., ) are more similar to those found in diploid than in polyploid plant species (Hoeltgebaum & dos Reis, ; Kim, Shin, & Choi, ; Sampson & Byrne, ).…”

Caracterização do crescimento e produção de óleo essencial da erva baleeira (Varronia curassavica Jaqc)

“…J.S.Mill.) (Silva &Stapf, 2020;Leal-Costa & Amélia, 2017;Brito et al, 2016;Stapf, 2010) pertence à família das Boraginaceae, é nativa da Mata Atlântica e encontra-se espalhada em quase todo o Brasil, habitando diversos tipos de vegetação tais como a caatinga, cerrado, floresta ombrófila e restinga (Queiroz et al, 2020;Hoeltgebaum & Reis, 2017;Brandão et al, 2015). Também é conhecida popularmente como córdia, catinga-debarão, erva-preta, maria-milagrosa, maria-rezadeira e salicinia (Queiroz et al, 2016).…”

“…Diante dessa realidade, não há genótipos selecionados e indicados para determinadas condições. A respeito dos recursos genéticos da espécie, alguns trabalhos relatam as características morfológicas (Hoeltgebaum et al, 2018;Leal-Costa & Amélia, 2017;Pereira et al, 2016;Brandão et al, 2015), a diversidade genética (Hoeltgebaum et al, 2015;Hoeltgebaum & Reis, 2017) e aspectos de coleções de germoplasma da espécie. (Brito et al, 2016;Queiroz et al, 2020).…”

Auxin type and dilution vehicles on vegetative propagation of Varronia curassavica Jacq. and Melaleuca alternifolia Cheel

“…Although not commonly used for ornamental purposes, V. curassavica has an interesting potential in this regard, with a shrubby growth habit, dense inflorescences and white flowers, visited by a series of pollinators mainly Coleoptera, Hemiptera, Diptera and Hymenoptera (Brandão et al, 2015;Marques et al, 2019). Given the adaptability of the species to sandy areas of the Restinga (Hoeltgebaum and Reis, 2017) a seriously threatened ecosystem in Brazil, V. curassavica can consist of a strategic species to compose projects of functional landscaping, where plants are grown, in addition to their ornamental features, by their ecological functions or economic uses, integrating decoration with functionality (Alencar and Cardoso, 2015) Currently, however, the importance of V. curassavica comes mainly from the production of essential oil, commercially used in the form of analgesic and antiinflammatory drugs and muscle relaxants (Gilbert and Favoreto, 2012;Marques et al, 2019). Among these drugs, the topical anti-inflammatory Acheflan®, an herbal medicine, stands out.…”