Characterization of brazilian accessions of wild arachis species of section arachis (fabaceae) using heterochromatin detection and fluorescence in situ hybridization (FISH)

• Autores: Custodio, Adriana Regina; Seijo, José Guillermo; Montenegro Valls, José Francisco
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Genetics And Molecular Biology, 2013, vol. 36, no. 3, p. 364-370.
• Materia: Arachis; Chromosome; Genomes
• Institución: Universidad Nacional del Nordeste

Fil: Custodio, Adriana Regina. Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Programa de Pós-Graduação em Recursos Genéticos Vegetais; Brasil.
Fil: Custodio, Adriana Regina. Embrapa Genetic Resources and Biotechnology; Brasil.
Fil: Seijo, José Guillermo. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina.
Fil: Seijo, Jose Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste; Argentina.
Fil: Montenegro Valls, José Francisco. Embrapa Genetic Resources and Biotechnology; Brasil.
The cytogenetic characterization of Arachis species is useful for assessing the genomes present in this genus, for establishing the relationship among their representatives and for understanding the variability in the available germplasm. In this study, we used fluorescence in situ hybridization (FISH) to examine the distribution patterns of heterochromatin and rDNA genes in 12 Brazilian accessions of five species of the taxonomic section Arachis. The heterochromatic pattern varied considerably among the species: complements with centromeric bands in all of the chromosomes (A. hoehnei) and complements completely devoid of heterochromatin (A. gregoryi, A. magna) were observed. The number of 45S rDNA loci ranged from two (A. gregoryi) to eight (A. glandulifera), while the number of 5S rDNA loci was more conserved and varied from two (in most species) to four (A. hoehnei). In some species one pair of 5S rDNA loci was observed adjacent to 45S rDNA loci. The chromosomal markers revealed polymorphism in the three species with more than one accession (A. gregoryi, A. magna and A. valida) that were tested. The previous genome assignment for each of the species studied was confirmed, except for A. hoehnei. The intraspecific variability observed here suggests that an exhaustive cytogenetic and taxonomic analysis is still needed for some Arachis species.