RÉSUMÉ
PREMISE: Despite the efforts to understand the processes that shape neotropical biodiversity, the complexity of certain biomes, such as the Atlantic Forest (AF), prevents the generalization of patterns. Initially, ecological niche modeling (ENM), with phylogeographic studies, identified past stable areas in the central and northern portions of the AF, while the southern portion was thought to be highly fragmented. Here, we examined the phylogeography, historical patterns, genetic diversity, and population structure of Vriesea incurvata, an endemic species of the southern portion of the AF. METHODS: We evaluated 149 individuals using two plastid DNA regions (cpDNA) and 13 nuclear microsatellite markers (nuSSRs) to access the historical patterns, genetic diversity, and structure of V. incurvata populations. We also conducted historical demography and ENM analyses. RESULTS: We found moderate to high genetic diversity and low population structure for both genomes. The cpDNA network revealed high haplotype sharing. The ENM suggested no drastic changes in suitable areas for V. incurvata occurrence, corroborating the finding of no phylogeographic structure. CONCLUSIONS: Contrary to some studies, our results indicate that the southern AF was a historically stable climate region for V. incurvata occupation after southward colonization by the species. Past climatic changes probably did not cause structuring among its populations.
Sujet(s)
Bromeliaceae/génétique , Écosystème , Flux des gènes , Variation génétique , Modèles biologiques , Brésil , Climat , Haplotypes , PhylogéographieRÉSUMÉ
PREMISE OF THE STUDY: Expressed sequence tag-simple sequence repeat (EST-SSR) markers were isolated for Vriesea carinata, an endemic bromeliad from the Brazilian Atlantic Forest. These SSR loci may be used to investigate the genetic diversity and population structure of this species and related bromeliads. METHODS AND RESULTS: Based on the transcriptome data of V. carinata, 30 primer pairs were designed and selected for initial validation. Of these primer pairs, 16 generated suitable SSR loci in 69 individuals. The number of alleles per locus ranged from one to 13; the levels of observed and expected heterozygosity per locus ranged from 0.000 to 1.000 and from 0.000 to 0.935, respectively. All loci produced heterologous amplification. Transferability of the loci was tested in 15 species belonging to three Bromeliaceae subfamilies. CONCLUSIONS: The developed EST-SSR markers revealed polymorphism in the four studied populations and could be useful to investigate the genetic diversity of V. carinata and related species. The markers may also be suitable for novel gene annotation and discovery.