Dissecting maize diversity in lowland South America : genetic structure and geographic distribution models

• Autores: Bracco, Mariana; Cascales, Jimena; Cámara Hernández, Julián A.; Poggio, Lidia; Gottlieb, Alexandra M.; Lia, Verónica V.
• Año de publicación: 2016
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: BMC Plant Biology; Vol.16; Art.186; http://www.biomedcentral.com/
• Materia: GENETIC DIVERSITY; GEOGRAPHIC DISTRIBUTION MODELS; GUARANI COMMUNITIES; LOWLAND SOUTH AMERICA; MAIZE LANDRACES
• Institución: Universidad de Buenos Aires. Facultad de Agronomía

Fil: Bracco, Mariana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Buenos Aires, Argentina.
Fil: Bracco, Mariana. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Escuela de Ciencias Agrarias, Naturales y Ambientales. Pergamino, Buenos Aires, Argentina.
Fil: Cascales, Jimena. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Buenos Aires, Argentina.
Fil: Cascales, Jimena. CONICET. Buenos Aires, Argentina.
Fil: Cámara Hernández, Julián A. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.
Fil: Poggio, Lidia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Buenos Aires, Argentina.
Fil: Poggio, Lidia. CONICET. Buenos Aires, Argentina.
Fil: Gottlieb, Alexandra M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Buenos Aires, Argentina.
Fil: Gottlieb, Alexandra M. CONICET. Buenos Aires, Argentina.
Fil: Lia, Verónica V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Buenos Aires, Argentina.
Fil: Lia, Verónica V. CONICET. Buenos Aires, Argentina.
Fil: Lia, Verónica V. Instituto de Biotecnología, CICVyA, INTA. Hurlingham, Buenos Aires, Argentina.Buenos Aires, Argentina.
Background: Maize landraces from South America have traditionally been assigned to two main categories: Andean and Tropical Lowland germplasm. However, the genetic structure and affiliations of the lowland gene pools have been difficult to assess due to limited sampling and the lack of comparative analysis. Here, we examined SSR and Adh2 sequence variation in a diverse sample of maize landraces from lowland middle South America, and performed a comprehensive integrative analysis of population structure and diversity including already published data of archaeological and extant specimens from the Americas. Geographic distribution models were used to explore the relationship between environmental factors and the observed genetic structure. Results: Bayesian and multivariate analyses of population structure showed the existence of two previously overlooked lowland gene pools associated with Guaraní indigenous communities of middle South America. The singularity of this germplasm was also evidenced by the frequency distribution of microsatellite repeat motifs of the Adh2 locus and the distinct spatial pattern inferred from geographic distribution models. Conclusion: Our results challenge the prevailing view that lowland middle South America is just a contact zone between Andean and Tropical Lowland germplasm and highlight the occurrence of a unique, locally adapted gene pool. This information is relevant for the conservation and utilization of maize genetic resources, as well as for a better understanding of environment-genotype associations.