Format: ORAL

Julissa Roncal1, Marinoli Rivas-Chamorro2, Victor Jimenez-Vasquez2, Betty Milln2, Nicolas Peafiel Loaiza1, Nora H. Oleas3, Monica Moraes4

1 Memorial University of Newfoundland, St. John’s, Canada 2 Universidad Nacional Mayor de San Marcos, Lima, Peru 3 Universidad Tecnológica Indoamérica, Quito, Ecuador 4 Universidad Mayor de San Andrés, La Paz, Bolivia

Landscape reconfigurations in South America have influenced the evolution of tropical plants by triggering diversification through niche partitioning, by facilitating dispersal, or separating ancestral populations. However, the genetic characterization of intraspecific entities or species delimitation remains a primary objective to which we can link the ecological factors that influence their evolution. Using several sequencing technologies and marker types, we assess the genetic variation within two palm lineages growing in two biomes, Amazonia and the Andes; and link the resulting genetic entities to putative environmental conditions that may be acting as selection. Astrocaryum section Huicungo is a complex of 15 morphologically defined species, the majority of which grow in western Amazonia. We found evidence of cytonuclear discordance where the two major lineages recovered in phylogenetic analyses almost matched. A Bayesian species delimitation test rendered three putative species occupying areas of contrasting geological activity. Preliminary ecological niche modeling show that putative species have different niches characterized by elevation and precipitation seasonality. The case of the Andean palm genus Parajubaea is similar in that we found genetic groups occupying different elevations, habitats and geological substrates. The delimitation of two morphologically defined, endemic, IUCN endangered species in Bolivia was challenged by our sequencing data that favored the recognition of three intraspecific genetic groups. Genetic groups showed admixture, no evidence of inbreeding, and we use them to propose management units for conservation. Many palm lineages, especially widespread species complexes, still await an assessment of intraspecific variation or a reconsideration of species limits combined with fine scale niche analyses. High throughput sequencing provides an unparalleled opportunity to unmask genetic differences, which is needed to improve our knowledge of ecological speciation in palms at higher resolutions.