INVESTIGADORES
LAVIA graciela ines
congresos y reuniones científicas
Título:
Integrating the cytogenetic and molecular phylogenetic data to the analysis of karyotypic evolution of the genus Arachis
Autor/es:
ROBLEDO, G.; SILVESTRI, M.C.; ORTIZ, A.M.; SAMOLUK, S.; SEIJO, J.G.; LAVIA, G.I.
Lugar:
Córdoba
Reunión:
Conferencia; 9th International Conference of the Peanut Research Community; 2017
Institución organizadora:
Ministerio de Ciencia y Tecnología de Córdoba, IBONE (UNNE-CONICET), Cámara Argentina del Maní, Fundación Maní Argentino, INTA, Criadero El Carmen y The Peanut Foundation
Resumen:
Arachis genus includes 81 autogamous and geocarpic species, all native from South America. Most of them are diploids with x=10, 4 are diploids with x=9, and 5 are tetraploids with x=10. Based on morphology and cross-compatibility, these species were arranged in 9 taxonomic sections and different genomes. Comparative studies by classical and molecular cytogenetics revealed large karyotype variability among species. This systematization of the karyotype analyses allowed us to propose several taxonomic and genomic arrangements, and infer the parental of the tetraploids species. Using the generated dataset, we constructed a tentative scheme about to the evolutive changes in different chromosome markers (45S and 5S rDNA and C-DAPI+ heterochromatic distribution) and DNA content in a phylogenetic context based on ITS sequences. This analysis allowed infer a tentative ancestral karyotype and that in the evolutionary history of genus there is a general tendency of a genome size (Cx) increase, that reduction of the basic chromosome number occurred twice, the polyploidization more than once, and the ?A chromosomes? originated only once. Some features such as low DNA content, lower chromosomal length, and absence or reduced content of heterochromatin C-DAPI+ characterize the basal sections. Despite of most of chromosome characteristic analyzed did not show a unidirectional tendency during evolutionary history, changes in the number of rDNA sites and in the patterns of DAPI heterochromatic distribution were related with the differentiation of genomic groups and some species.