Range-wide patterns of nuclear and chloroplast DNA diversity in Vriesea gigantea (Bromeliaceae), a neotropical forest species

Abstract

The processes that have shaped the extraordinary species diversity in neotropical rainforests are poorly understood, and knowledge about the patterns of genetic diversity across species' ranges is scarce, in contrast to other regions of the globe. We have conducted a range-wide study of genetic diversity in a plant endemic to the Brazilian Atlantic Rainforest, Vriesea gigantea (Bromeliaceae), based on a combined data set of nuclear microsatellites and chloroplast (cp) DNA markers typed in 429 plants from 13 populations. The results indicate a strong negative correlation between genetic diversity and population latitude, consistent with historical forest expansion from the northern half of the present distribution range. A deep phylogeographic split exists between the Brazilian states of São Paulo and Rio de Janeiro at ca. 23 1S latitude, probably reflecting past population isolation within more than one glacial refuge during the climatic changes of the Pleistocene. A comparison of genetic structures at cpDNA and nuclear markers revealed a pollen/ seed flow ratio of more than 3:1, thus indicating an important role of the pollinating animals (that is, bats) in shaping the population genetic structure of this species. Diversity was reduced for cpDNA markers in the island populations off the coast, and reduced diversity and increased differentiation were observed for both nuclear and cpDNA at the edges of the species' range. The link between patterns of genetic and species diversity supports the hypothesis that both were shaped by the same biogeographic processes, triggered by the climatic oscillations of the Pleistocene.

How fat is the tail?

“…The study by Palma-Silva et al (2009) in this issue is a good example of phylogeographic investigation on a tropical plant in a particularly damaged hotspot of diversity-the Brasilian Atlantic Rainforest. Using the same types of genetic markers as Kamm et al (2009), that is nuclear microsatellites and chloroplast DNA sequences, the authors analyzed geographic patterns of genetic variation at the species level.…”

Genetic diversity of Bromeliaceae species from the Atlantic Forest

“…Plants in the Bromeliaceae family provide excellent models for the study of genetic diversity (Zanella et al, 2012;Hmeljevski et al, 2013), population genetics (Lavor et al, 2014), as well as the divergence between populations and species (Sarthou et al, 2001;Barbará et al, 2007;Palma-Silva et al, 2009). Bromeliads are an important and characteristic element of Neotropical forests, especially in the Brazilian Atlantic Forest (BAF), where they are among those families with the greatest richness and diversity (Martinelli et al, 2008).…”

“…Nevertheless, relatively few genetic studies have examined Neotropical plant species and investigated genetic aspects of BAF bromeliads by comparing temperate forests (Cavallari et al, 2006;Barbará et al, 2007;Palma-Silva et al, 2009;Versieux et al, 2012;Zanella et al, 2012;Lavor et al, 2014;Goetze et al, 2015). According to Zanella et al (2012), only 20 species of the following nine genera have been previously evaluated, and most of the studied species are endemic to the Atlantic rainforest in southeastern Brazil: Aechmea, Alcantarea, Bromelia, Dyckia, Encholirium, Pitcairnia, Puya, Tillandsia, and Vriesea. However, this biome has been severely destroyed and reduced to only 13% approximately of its original area, which is the main threat to BAF flora and fauna (Ribeiro, 2009).…”

Assessing genetic divergence in interspecific hybrids of Aechmea gomosepala and A. recurvata var. recurvata using inflorescence characteristics and sequence-related amplified polymorphism markers

“…This information could also guide the selection of promising materials and new crosses and elucidate the mechanism by which horticultural traits are inherited. Previous studies have assessed the genetic diversity among various bromeliad species (Izquierdo and Pinero, 2000;Barfuss et al, 2005;Sousa et al, 2008;Palma-Silva et al, 2009;Boisselier-Dubayle et al, 2010); however, little information is available on the genetic divergence among interspecific hybrids in Aechmea.…”