Andean orogenesis has driven the development of very high plant diversity in theNeotropics through its impact on landscape evolution and climate. The analysis ofthe intraspecific patterns of genetic structure in plants would permit inferring theeffects of Andean uplift on the evolution and diversification of Neotropical flora. Inthis study, using microsatellite markers and Bayesian clustering analyses, we reportthe presence of four genetic clusters for the palm Oenocarpus bataua var. batauawhich are located within four biogeographic regions in northwestern South America:(a) Chocó rain forest, (b) Amotape-Huancabamba Zone, (c) northwestern Amazonianrain forest, and (d) southwestern Amazonian rain forest. We hypothesize that theseclusters developed following three genetic diversification events mainly promoted byAndean orogenic events. Additionally, the distinct current climate dynamics amongnorthwestern and southwestern Amazonia may maintain the genetic diversificationdetected in the western Amazon basin. Genetic exchange was identified betweenthe clusters, including across the Andes region, discarding the possibility of any cluster to diversify as a distinct intraspecific variety. We identified a hot spot of geneticdiversity in the northern Peruvian Amazon around the locality of Iquitos. We alsodetected a decrease in diversity with distance from this area in westward and southward direction within the Amazon basin and the eastern Andean foothills. Additionally,we confirmed the existence and divergence of O. bataua var. bataua from var. oligocarpus in northern South America, possibly expanding the distributional range of thelatter variety beyond eastern Venezuela, to the central and eastern Andean cordilleras of Colombia. Based on our results, we suggest that Andean orogenesis is themain driver of genetic structuring and diversification in O. bataua within northwestern South America.
Bibliographical noteFunding Information:
We would like to thank three anonymous reviewers for enhancing the quality of a former version of this manuscript. We thank Cédric Mariac, Marie Couderc, Julissa Roncal, and the entire ?YNA?IV team from the IR? (Montpellier, France) for helping during laboratory work. Special thanks go to Jean-Jacques de Granville (IR?) for the valuable support during the sampling in French Guiana; to José Manuel Barreiro, María José Sanín, Gabriel Rivadeneira, Luis López, and John Colorado for assistance during fieldwork; and to Christine Fram for grammar and style correction of the manuscript. FP7-PALMS-project (Palms Harvest Impacts in Tropical Forests; EU-contract 212631 and the ?anish Council for Independent Research-Natural Sciences [grant#4181-00158] to Henrik Balslev) and PUCE (Project “Oenocarpus bataua”) supported this research financially. The Ministerio del Ambiente-Ecuador (N°004-IC-FLO-?PPZ/MA, N°06-2012-INVESTIGACIÓN-B-?P/MS/MAE, N°009-IC-FAU/FLO-?PZCH-MA), ?irección General Forestal y de Fauna Silvestre-Peru (0118-2009-AG-?GFFS-?GEFFS), Ministerio de Medio Ambiente y Agua-Bolivia (1088), and Autoridad Nacional de Licencias Ambientales-Colombia (ANLA 0255) gave us permission to collect the needed samples. Samples from French Guiana were obtained with the collaboration of the IR?, France.
© 2018 The Authors.
- Genetic divergence
- Genetic diversity
- Microsatellite markers