Exploring karyotype diversity of Argentinian Guaraní maize landraces : relationship among South American maize

Realini, María Florencia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución, Laboratorio de Citogenética y Evolución (LaCyE). Buenos Aires, Argentina. ; Poggio, Lidia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución, Laboratorio de Citogenética y Evolución (LaCyE). Buenos Aires, Argentina. ; Cámara Hernández, Julián A. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica Agrícola. Buenos Aires, Argentina. ; González, Graciela Esther. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución, Laboratorio de Citogenética y Evolución (LaCyE). Buenos Aires, Argentina. ; e0198398 ; In Argentina there are two different centers of maize diversity, the Northeastern (NEA) and the Northwestern (NWA) regions of the country. In NEA, morphological studies identified 15 landraces cultivated by the Guaraní communities in Misiones Province. In the present study we analyzed the karyotype diversity of 20 populations of Guaraní maize landraces through classical and molecular cytogenetic analyses. Our results demonstrate significant intra and inter - populational variation in the percentage, number, size, chromosome position and frequencies of the heterochromatic blocks, which are called knobs. Knob sequence analysis (180 - bp and TR-1) did not show significant differences among Guaraní populations. B chromosomes were not detected, and abnormal 10 (AB10) chromosomes were found with low frequency (0.1f 0.40) in six populations. Our results allowed karyotypic characterization of each analyzed population, defining for the first time the chromosomal constitution of maize germplasm from NEA. The multivariate analysis (PCoA and UPGMA) of karyotype parameters allowed the distinction between two populations groups: the Popcorn and the Floury maize populations. These results are in agreement with previously published ...