A Biogeographic Barrier Test Reveals a Strong Genetic Structure for a Canopy-Emergent Amazon Tree Species

Author(s)

Nazareno, Alison G. ^[1] ; Dick, Christopher W. ^[2] ; Lohmann, Lucia G. ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Bot, Sao Paulo, SP - Brazil

^[2] Univ Michigan, Dept Ecol & Evolutionary Biol, Ann Arbor, MI 48109 - USA

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 9, DEC 9 2019.
• Web of Science Citations: 6

Abstract

Wallace's (1854) Riverine Barrier hypothesis is one of the earliest explanations for Amazon biotic diversification. Despite the importance of this hypothesis for explaining speciation in some animal groups, it has not been studied extensively for plant species. In this study we use a prominent Amazon tree, Buchenavia oxycarpa (Mart.) Eichler (Combretaceae), to evaluate Wallace's hypothesis along the Rio Negro, a major Amazon tributary that has driven allopatric speciation for several animal taxa. We sampled six individuals from sixteen localities along both river banks, and used a modified ddRADseq protocol to identify SNP markers. Our population genomic data revealed strong genetic structure for B. oxycarpa sampled across banks of the Rio Negro (phi(CT) = 0.576, P < 0.001), supporting the hypothesis that the Rio Negro acted as a significant genetic barrier for B. oxycarpa. Our study shows that gene flow for this large and well-dispersed Amazon tree is impeded by riverine barriers, though this has not yet resulted in speciation. Future studies focused on species with different life histories, including species restricted to non-flooded forests, are needed to further advance our understanding of Amazon rivers as drivers of biotic diversification. (AU)

• FAPESP's process: 15/07141-4 - A test of the riverine barrier hypothesis for Amazonian plants
• Grantee: Alison Gonçalves Nazareno
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 17/02302-5 - Crossing Amazonian rivers: a comparative study of plants with distinct life histories
• Grantee: Alison Gonçalves Nazareno
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 13/12633-8 - Comparative phylogeography of plants in the Central Amazonia
• Grantee: Alison Gonçalves Nazareno
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 12/50260-6 - Structure and evolution of the Amazonian biota and its environment: an integrative approach
• Grantee: Lúcia Garcez Lohmann
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants