Caracterización genómica de las especies con x=9 de la sección Arachis (Arachis, Leguminosae).

SILVESTRI MARÍA CELESTE; ORTIZ, ALEJANDRA MARCELA.; LAVIA, GRACIELA INÉS

Brasilia

Conferencia; VIII ENCUENTRO LATINOAMERICANO DE ESPECIALISTAS EN ARACHIS; 2013

Embrapa Recursos Genéticos y Biotecnología

The genus Arachis (Leguminosae; 80 spp.) is genetically well-known; most species are diploid with x=10 and only four species have x=9. Three of these x=9 species belong to section Arachis and are morphologically and chromosomally similar, but their genome type is still unknown. To provide information about the homology of the genomes of x=9 species and their relation to other genomes in section Arachis, we analyzed species using fluorescence in situ hybridization (FISH) of 18S-26S and 5S rDNA sites and 4´, 6-diamidino-2-phenylindole (DAPI) banding. FISH analyses showed that all three species have a pair of 5S rDNA sites in the interstitial region of the short arm of metacentric pair 6 and a pair of 18S-26S rDNA sites in the proximal region of the long arm of the SAT chromosomes. Conspicuous DAPI+ bands were detected pericentromerically in all nine chromosome pairs in A. decora and A. praecox and in all but one pair in A. palustris. Our results suggest that all three species with x=9 of section Arachis share the same genome type and that they are different from the other genome types A, B, D, F, and K described for section Arachis. Therefore, the x=9 species of section Arachis would form a monophyletic group characterized by its own genome type, that we here propose as the G genome.