Theoretical and Applied Genetics

, Volume 103, Issue 4, pp 486–490

Ribosomal DNA is an effective marker of Brassica chromosomes

  • R. Hasterok
  • G. Jenkins
  • T. Langdon
  • R. N. Jones
  • J. Maluszynska

DOI: 10.1007/s001220100653

Cite this article as:
Hasterok, R., Jenkins, G., Langdon, T. et al. Theor Appl Genet (2001) 103: 486. doi:10.1007/s001220100653

Abstract  

Simultaneous fluorescence in situ hybridisation with 5S and 25S rDNA probes enables the discrimination of a substantial number of chromosomes of the complement of all diploid and tetraploid Brassica species of the ”U-triangle”, and provides new chromosomal landmarks for the identification of some chromosomes of this genus which were hitherto indistinguishable. Twelve out of 20 chromosomes can be easily identified in diploid Brassica campestris (AA genome), eight out of 16 in Brassica nigra (BB genome), and six out of 18 in Brassica oleracea (CC genome). Furthermore, just two rDNA markers permit 20 out of 36 chromosomes to be distinguished and assigned to either the A or B genomes of the allotetraploid Brassica juncea, and 18 out of 38 chromosomes identified and assigned to the A or C genomes of the allotetraploid Brassica napus. The number of chromosomes bearing rDNA sites in the tetraploids is not in all cases simply the sum of the numbers of sites in their diploid ancestors. This observation is discussed in terms of the phylogeny and variability within the genomes of the species of this group.

Keywords Brassica Double-target FISH 5S rDNA 25S rDNA 

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • R. Hasterok
    • 1
  • G. Jenkins
    • 2
  • T. Langdon
    • 2
  • R. N. Jones
    • 2
  • J. Maluszynska
    • 1
  1. 1.Department of Plant Anatomy and Cytology, Silesian University, Jagiellonska 28, 40-032 Katowice, Poland e-mail: hasterok@us.edu.pl Tel: +48-(32)-2009-553, Fax: +48-(32)-255-58-73PL
  2. 2.Institute of Biological Sciences, University of Wales, Aberystwyth, Ceredigion, SY23 3DD, UKGB

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