Karyotypic studies in wild species of Arachis (Leguminosae) belonging to sections Erectoides, Procumbentes and Rhizomatosae

ORTIZ, A.M.; FERNÁNDEZ, A; LAVIA, G.I.

Buenos Aires (Argentina)

Encuentro; VII Encuentro Internacional de Especialistas en Arachis.; 2010

Instituto Nacional de Tecnología Agropecuaria - INSTITUTO DE BOTÁNICA DEL NORDESTE

Arachis is native from South America and has 80 formally recognized species. These entities were assembled into nine sections according to morphology, geographic distribution and hybrid fertility. The phylogenetic relationships between these species have been investigated by molecular analysis, cross compatibility experiments and cytogenetic studies. However, the chromosomal features of all Arachis species have not yet been described. Therefore, to increase the knowledge of this genus, the karyotypes of three diploid species belonging to sections Erectoides, Procumbentes (A. rigonii) and Rhizomatosae A. burkartii) were analyzed by Feulgen´s technique. The karyotype formula was different in the analyzed taxa: 2n=2x=16m+4sm in A. hermannii, 2n=2x=18m+2sm in A. rigonii, and 2n=2x=20m in A. burkartii. All species had a pair of satellited chromosomes, which corresponded to type 2 in A. hermannii, type 9 in A. rigonii, and type 8 in A. burkartii. Arachis hermannii and A. rigonii presented similar chromosomal features to the species included in their respective sections. However, A. burkartii had a different type of satellited chromosome to that found in the tetraploid species of section Rhizomatosae.