Landscape and climatic features drive genetic differentiation processes in a South American coastal plant

Gustavo A Silva-Arias,Loreta B Freitas,Giovanna C Giudicelli,Lina Caballero-Villalobos

doi:10.1186/s12862-021-01916-4

Gustavo A Silva-Arias, Loreta B Freitas + Show 2 more

Open Access

https://doi.org/10.1186/s12862-021-01916-4

Copy DOI

Abstract

BackgroundHistorical and ecological processes shape patterns of genetic diversity in plant species. Colonization to new environments and geographical landscape features determine, amongst other factors, genetic diversity within- and differentiation between-populations. We analyse the genetic diversity and population structure of Calibrachoa heterophylla to infer the influence of abiotic landscape features on the level of gene flow in this coastal species of the South Atlantic Coastal Plain.ResultsThe C. heterophylla populations located on early-deposited coastal plain regions show higher genetic diversity than those closer to the sea. The genetic differentiation follows a pattern of isolation-by-distance. Landscape features, such as water bodies and wind corridors, and geographical distances equally explain the observed genetic differentiation, whereas the precipitation seasonality exhibits a strong signal for isolation-by-environment in marginal populations. The estimated levels of gene flow suggest that marginal populations had restricted immigration rates enhancing differentiation.ConclusionsTopographical features related to coastal plain deposition history influence population differentiation in C. heterophylla. Gene flow is mainly restricted to nearby populations and facilitated by wind fields, albeit without any apparent influence of large water bodies. Furthermore, differential rainfall regimes in marginal populations seem to promote genetic differentiation.

Highlights

Historical and ecological processes shape patterns of genetic diversity in plant species
Populations located outside of South Atlantic Coastal Plain (SACP) (I1-3) and those collected around the Patos Lagoon (W1-2 and S1-2) showed higher genetic diversity (Fig. 1A, B)
We found 22% of the alleles restricted to a single population, with W1 showing the highest number of private alleles, whereas

Summary

Introduction

Historical and ecological processes shape patterns of genetic diversity in plant species. Colonization to new environments and geographical landscape features determine, amongst other factors, genetic diversity withinand differentiation between-populations. We analyse the genetic diversity and population structure of Calibrachoa heterophylla to infer the influence of abiotic landscape features on the level of gene flow in this coastal species of the South Atlantic Coastal Plain. Climate, oceanographic features, and colonization events from the surrounding biomes shape the ecosystems of these areas [1,2,3,4,5,6]. Studies on plant diversification in South America have received increased attention, analyses focusing on the colonization of coastal areas, migration and gene flow between populations, and recent speciation events are still scarce [9,10,11].

Objectives

Methods

Results

Discussion

Conclusion