INVESTIGADORES
SEIJO Jose Guillermo
artículos
Título:
Characterization of Brazilian accessions of wild Arachis species of section Arachis (Fabaceae) using heterochromatin detection and fluorescence in situ hybridization (FISH).
Autor/es:
CUSTODIO, AR; SEIJO JG; J.F.M. VALLS
Revista:
GENETICS AND MOLECULAR BIOLOGY
Editorial:
SOC BRASIL GENETICA
Referencias:
Año: 2013 vol. 36 p. 364 - 370
ISSN:
1415-4757
Resumen:
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.