Phylogeography, population genomics and speciation of naturally fragmented populations of Bromeliaceae

Abstract

Neotropics encompass large number of hotspot regions to conservation, however the knowledge about patters and process responsible to shape its outstanding biodiversity are still emerging. Multidisciplinary approaches such as, systematics, phylogeography, population genetics and genomics, ecology and morphometry can significantly contribute to identify important evolutionary processes in groups of species with difficult delimitation. This integrative approach can be useful in regions with high biodiversity, such as Neotropics, aiming sustainable use and conservation. Two critical issues are particularly relevant to species delimitation using integrative approaches. One is that of dealing with naturally fragmented populations. The other is making decisions about lineages that are currently hybridizing and introgressing. Those are challenges in characterizing biodiversity, especially in groups of recent radiation, such as bromeliads, with exceptional levels of beta-diversity and microendemism, especially in naturally fragmented habitats as the outcrops in Southeastern Brazil. In this project we aim to: 1) characterize genetic and morphological variation in a bromeliad species complex (Pitcairnia flammea), occurring in naturally fragmented habitat in the Atlantic rainforest; 2) contribute to species delimitation of this species complex using integrative analyses of phylogeography, population genomics, morphometry, and ecological niche modelling; 3) investigate reproductive isolation among population and lineages and the role of intra and inter-specific gene flow in maintain species integrity and cohesion among these lineages; 4) study the evolutionary history to infer mechanisms and processes responsible for phylogeographical patterns of this species complex by using (a) nuclear and plastidial sanger sequencing, and (b) a large set of SNPs isolated by RAD-seq; 5) combine molecular, genomic and NEM data sets to better understand how demographic history of these populations influenced current geographic distribution of genetic variation; 6) identify SNPs associated with candidate genes sob-selection in P. flammea populations, that may be responsible for local adaptation. Comparing neutral and adaptive genomic patterns will allow us to discuss the long term effects of population fragmentation in reproductive fitness and evolutionary potential of naturally fragmented populations. Furthermore, a better understanding of these processes will allow to preview the consequences of global climatic changes and the effects of naturally and anthropic fragmentation in speciation and adaptation in regions of outstanding biodiversity. These information are fundamental to understand processes responsible for shaping species diversity in these biomes, aiming sustainable use and conservations of these and other species adapted to fragmented habitats. (AU)