Theoretical and Applied Genetics

, Volume 87, Issue 8, pp 893–899

Variability in rDNA loci in the genus Oryza detected through fluorescence in situ hybridization


  • K. Fukui
    • Hokuriku National Agricultural Experiment Station
  • N. Ohmido
    • Hokuriku National Agricultural Experiment Station
  • G. S. Khush
    • International Rice Research Institute

DOI: 10.1007/BF00225782

Cite this article as:
Fukui, K., Ohmido, N. & Khush, G.S. Theoret. Appl. Genetics (1994) 87: 893. doi:10.1007/BF00225782


The 17s-5.8s-25s ribosomal RNA gene (rDNA) loci in Oryza spp. were identified by the fluorescence in-situ hybridization (FISH) method. The rDNA loci were located on one-to-three chromosomes (two-to-six sites) within the eight diploid Oryza spp. One of the rDNA loci gave the weakest hybridization signal. This locus is reported for the first time in the genus Oryza. The chromosomes containing the rDNA loci were determined to be numbers 9, 10 and 11 in descending order of the copy number of rDNA. The application of image analysis methods, after slide preparation treatments (post-treatments), and the use of a thermal cycler, greatly improved the reproducibility of the results. The evolutionary significance of the variability of rDNA loci among the Oryza spp. is discussed.

Key words

Fluorescence in-situ hybridization (FISH)Ribosomal DNAGenus OryzaImage analysisNOR variability

Copyright information

© Springer-Verlag 1994