Genetic structure of Dicksonia sellowiana Hook. (Dicksoniaceae) reveals clinal distribution along the latitudinal gradient of the Atlantic Forest

Bruna Saviatto Fagundes,Maria Augusta Poersch,Valeria Cunha Muschner,Jaqueline Dos Santos,Paulo Henrique Labiak,André Luiz Gaglioti

doi:10.1590/0102-33062020abb0234

Bruna Saviatto Fagundes, Maria Augusta Poersch + Show 4 more

Open Access

https://doi.org/10.1590/0102-33062020abb0234

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Abstract

ABSTRACT Dicksonia sellowiana is the only species of the genus occurring in Brazil. Its distribution is restricted to humid areas of the Atlantic Forest biome. The distribution pattern of biodiversity in this biome is known to have been influenced by historical and environmental factors, although the pattern for ferns remains unknown. This study is first to describe the genetic structure of D. sellowiana along the latitudinal gradient of the Atlantic Forest biome. We use microsatellite markers to estimate genetic diversity and structure for 267 individuals representing 14 populations of D. sellowiana from the Atlantic Forest. The results (Ho, He, Fst, Fis, distance genetic) support the hypothesis of a pattern of biodiversity discontinuity. We found greater genetic variability in populations located in regions of higher humidity and milder temperatures. Our data suggest that there is a clinal distribution pattern of genetic variation along the north to south latitudinal gradient of the Atlantic Forest. This clinal variation has a genetic basis in the frequencies of the two genetic groups. This structure does not evidence long-standing historical barriers to gene flow and favors the influence of landscape characteristics on the establishment of populations.

Highlights

Biodiversity studies of hotspots aim to increase knowledge about the richness and dynamics of native species in order to safeguard biomes (Myers et al 2000)
Our sampling included a total of 267 individuals representing 14 populations of Dicksonia sellowiana from the Southeast and South regions of Brazil (Tab. 1)
We studied the genetic diversity and population structure of Dicksonia sellowiana, an endemic species of the Neotropics

Summary

Introduction

Biodiversity studies of hotspots aim to increase knowledge about the richness and dynamics of native species in order to safeguard biomes (Myers et al 2000). Native species of the Atlantic Forest exhibit different patterns of biological diversity as a result of its extensive latitudinal gradient, which, in turn, is correlated with environmental variation along the area of occurrence of the biome in the east coast region of the Neotropics Oscillations in temperature and humidity during the Quaternary resulted in the distribution of species in refuges along the entire latitudinal gradient of the Atlantic Forest (Behling 1997; 2002; Carnaval & Bates 2007; Carnaval et al 2014). Historical factors related to the distribution of flora can be understood via studies of the patterns of genetic diversity of native species of the Atlantic Forest (Behling 1997; 2002; CBD 2016)

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