Theoretical and Applied Genetics

, Volume 103, Issue 6, pp 846–854

Karyotype analysis reveals interspecific differentiation in the genus Cedrus despite genome size and base composition constancy

  • M. Bou Dagher-Kharrat
  • G. Grenier
  • M. Bariteau
  • S. Brown
  • S. Siljak-Yakovlev
  • A. Savouré

DOI: 10.1007/s001220100640

Cite this article as:
Bou Dagher-Kharrat, M., Grenier, G., Bariteau, M. et al. Theor Appl Genet (2001) 103: 846. doi:10.1007/s001220100640

Abstract  

The DNA content and GC% of the four true cedar (Cedrus) species, C. atlantica, C. brevifolia, C. deodara and C. libani, were assessed. Genome size was homogeneous among representative populations of the four species with an average of 32.6±0.6 pg per 2 C or 15.7×109 base pairs per 1 C. The composition in GC was calculated to be 40.7%. A simple monosomatic haploid level was found in the megagametophyte, as compared to the diploid level of the corresponding embryo. Cytogenetic studies showed a diploid chromosome number of 2n=2x=24 in 11 populations sampled over the four species. The chromosome complements have similar morphology and symmetry. However, fluorochromes revealed specific banding patterns in each of the four cedar species. Eight GC-rich chromomycin A3 bands were observed in Cedrus deodara chromosomes, six in both Cedrus libani and Cedrus brevifolia, and four bands in Cedrus atlantica chromosomes. Moreover, Hoechst 33258 fluorochrome revealed AT-rich sequences specifically located in the centromeric regions while the GC-rich sequences appeared negatively stained. These investigations provide a systematic characterisation of the Cedrus genus and should contribute towards clarification of the phylogenetic relationships among the four species.

Keywords  Base compositionCedrusFluorochrome bandingGenome sizeKaryotype analysisGymnosperm

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • M. Bou Dagher-Kharrat
    • 1
  • G. Grenier
    • 2
  • M. Bariteau
    • 3
  • S. Brown
    • 4
  • S. Siljak-Yakovlev
    • 5
  • A. Savouré
    • 1
  1. 1.Physiologie Cellulaire et Moléculaire des Plantes, UMR 7632 CNRS, Université Pierre et Marie Curie, case 156, 4 Place Jussieu, 75252 Paris cedex 05, France e-mail: savoure@ccr.jussieu.fr; Tel.: +33-(0)1-44-27-26-72, Fax: +33-(0)-1-44-27-26-72FR
  2. 2.Institut Supérieur Agricole de Beauvais, Rue Pierre Waguet, 60026 Beauvais cedex, FranceFR
  3. 3.Unité de Recherches Forestières Méditerranéennes, INRA, av. Vivaldi, 84000 Avignon, FranceFR
  4. 4.Institut des Sciences Végétales, CNRS, 91198 Gif-sur-Yvette, FranceFR
  5. 5.Laboratoire d’Evolution et Systématique, UPRESA 8079, Université de Paris XI, Bât. 360, 91405 Orsay cedex, FranceFR