title: Efficiency of cytogenetic methods in detecting a chromosome rearrangement induced by ionizing radiation in a cultivated chili pepper line (Capsicum baccatum var. pendulum--Solanaceae).
abstract: OBJECTIVE
  To locate transient chromosome aberrations on a selected pepper cultivar and determine the tracing efficiency of different cytogenetic methods.
  
  
  METHODS
  Seeds from Capsicum baccatum var. pendulum cultivar 'Cayenne' were treated with an acute dose of X-rays (300 Gy) and chromosome aberrations were analysed by different cytogenetic methods [Feulgen, silver staining for nucleolus organizer regions (silver positive nucleolus organizing regions or AgNOR), fluorescent banding, fluorescence in situ hybridization (FISH) and meiotic analysis].
  
  
  RESULTS
  A rearranged chromosome carrying two nucleolus organizing regions (NOR) induced by ionizing radiation was detected in the cultivar, with the occurrence of a small reciprocal exchange between a chromosome of pair no. 1 and another chromosome of pair no. 3, both carrying active NOR in short arms and associated chromomycin A positive/diamidino-phenylindole negative (CMA+/DAPI-) heterochromatin. Meiotic analysis showed a quadrivalent configuration, confirming a reciprocal translocation between two chromosomes.
  
  
  CONCLUSIONS
  The use of X-rays in Capsicum allowed us to develop and identify a pepper line with structural rearrangements between two NOR-carrying chromosomes. We postulate that all the cytological techniques employed in this research were efficient in the search for chromosome aberrations. Particularly, Feulgen and AgNOR were the most suitable in those cases of transient rearrangements, whereas fluorescent banding and FISH were appropriate for intransitive ones.
authors.affiliation: Instituto Multidisciplinario de Biología Vegetal (IMBIV-CONICET) , Córdoba.
authors.forename: Marisel A
authors.initials: MA
authors.lastname: Scaldaferro
authors.forename: Mauro
authors.initials: M
authors.lastname: Grabiele
authors.forename: J Guillermo
authors.initials: JG
authors.lastname: Seijo
authors.forename: Humberto
authors.initials: H
authors.lastname: Debat
authors.forename: M Victoria
authors.initials: MV
authors.lastname: Romero
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Ducasse
authors.forename: Alberto R
authors.initials: AR
authors.lastname: Prina
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Moscone
mesh_terms: D001483:Base Sequence; D002212:Capsicum / Q000235:genetics* / Q000528:radiation effects*; D002869:Chromosome Aberrations / Q000528:radiation effects*; D020732:Cytogenetic Analysis / Q000379:methods*; D018744:DNA, Plant / Q000235:genetics* / Q000528:radiation effects*; D015321:Gene Rearrangement / Q000235:genetics* / Q000528:radiation effects; D008969:Molecular Sequence Data; D011829:Radiation Dosage
chemical_list: D018744:DNA, Plant