title: Cytogenetic studies in four cultivated Amaranthus (Amaranthaceae) species.
abstract: In the present study, the chromosomes numbers were confirmed, 2n = 34 for Amaranthus cruentus Linnaeus, 1759, and 2n = 32 for Amaranthus hypochondriacus Linnaeus, 1753, Amaranthus mantegazzianus Passer, 1864, and Amaranthus caudatus Linnaeus, 1753. The distribution and variability of constitutive heterochromatin were detailed using DAPI-CMA3 banding technique. The position of the nucleolus organizer region (NOR) was observed using Ag-NOR banding (active loci) and fluorescent in situ hybridization (rDNA-FISH) in the four Amaranthus species. Variations in the amount of constitutive heterochromatin were detected both within the species and between them, with DAPI-CMA3 stain. One chromosome pair having a NOR was found in each studied accession, with exception of Amaranthus caudatus cv. EEA INTA Anguil. This accession presented four rDNA loci (FISH), being active two of them (Ag- banding).
authors.affiliation: Cátedra de Botánica Agrícola, Facultad de Agronomía, Universidad de Buenos Aires. Av. San Martín 4453 (C1417DSE), Buenos Aires, Argentina.
authors.forename: Marisa Graciela
authors.initials: MG
authors.lastname: Bonasora
authors.forename: Lidia
authors.initials: L
authors.lastname: Poggio
authors.forename: Eduardo José
authors.initials: EJ
authors.lastname: Greizerstein
keywords: Amaranthus; DAPI-CMA3; FISH; NORs; constitutive heterochromatin