title: Karyotype analysis of Helianthus annuus using Giemsa banding and fluorescence in situ hybridization.
abstract: The karyotype of H. annuus was analysed by computer-aided image processing with respect to the chromosome length, arm ratio, occurrence and chromosomal position of intercalary heterochromatin and the location of 18S/25S and 5S ribosomal RNA genes. The karyotype was subdivided into a group of four acrocentric chromosome pairs, of which two were distinguishable by HKG (HCl, KOH, Giemsa) banding and a group of 13 meta- to submetacentric pairs. The latter could be subdivided into seven pairs with one and six pairs with two HKG bands. Three pairs of submetacentric satellite chromosomes revealed 18S/25S rDNA loci after fluorescence in situ hybridization (FISH) and silver staining. A fourth, smaller and possibly inactive, locus occurred in the terminal position on a metacentric pair. One submetacentric satellite chromosome pair revealed a 5S rRNA gene locus in the pericentromeric position; a second locus marked a submetacentric pair with one HKG band. The C-banding technique marks exclusively centromeric heterochromatin. Measurements of chromosomes in combination with Giemsa banding and FISH enabled the discrimination of most chromosome pairs of the sunflower.
authors.affiliation: Institut für Züchtungsmethodik bei Gemüse der Bundesanstalt für Züchtungsforschung an Kulturpflanzen, Quedlinburg, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Schrader
authors.forename: R
authors.initials: R
authors.lastname: Ahne
authors.forename: J
authors.initials: J
authors.lastname: Fuchs
authors.forename: I
authors.initials: I
authors.lastname: Schubert
mesh_terms: D001399:Azure Stains; D002871:Chromosome Banding; D002875:Chromosomes / Q000737:chemistry / Q000235:genetics; D004396:Coloring Agents; D015342:DNA Probes / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D006368:Helianthus / Q000235:genetics*; D007091:Image Processing, Computer-Assisted; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D012394:Rosaniline Dyes; D016622:Silver Staining; D013194:Staining and Labeling
chemical_list: D001399:Azure Stains; D004396:Coloring Agents; D015342:DNA Probes; D004275:DNA, Ribosomal; C007722:Feulgen stain; D012394:Rosaniline Dyes