Genomic relationships of the polyploid rhizoma peanut (Arachis glabrata Benth.) inferred by genomic in situ hybridization (GISH)

ORTIZ, A.M.; CHALUP, L.; SILVESTRI, M.C.; SEIJO, J.G.; LAVIA, G.I.

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2023

0001-3765

Abstract: The rhizoma peanut (Arachis glabrata Benth., section Rhizomatosae) is atetraploid perennial legume. Although several A. glabrata cultivars have been developedas forage and ornamental turf, the origin and genomic constitution of this species arestill unknown. In this study, we evaluated the affinity between the genomes of A. glabrataand the probable diploid donors of the sections Rhizomatosae, Arachis, Erectoidesand Procumbentes by genomic in situ hybridization (GISH). Single GISH analysesdetected that species of the sections Erectoides (E2 subgenome) and Procumbentes (E3subgenome) were the diploid species with the highest degree of genomic affinity with A.glabrata. Based on single GISH experiments and DNA sequence similarity, three species-A. duranensis, A. paraguariensis subsp. capibarensis, and A. rigonii-, which showed themost uniform and brightest hybridization patterns and lowest genetic distance, wereselected as probes for double GISH experiments. Double GISH experiments showed thatA. glabrata is constituted by four identical or very similar chromosome complements.In these assays, A. paraguariensis subsp. capibarensis showed the highest brightnessonto A. glabrata chromosomes. Thus, our results support the autopolyploid origin of A.glabrata and show that the species with E2 subgenome are the most probable ancestorsof this polyploid legume forage.