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Chromosoma

, Volume 106, Issue 1, pp 53–61 | Cite as

Genomic organization and phylogenetic relationships in the genus Dasypyrum analysed by Southern and in situ hybridization of total genomic and cloned DNA probes

  • I. Galasso
  • A. Blanco
  • A. Katsiotis
  • D. Pignone
  • J. S. Heslop-Harrison

Abstract.

Molecular cytogenetic methods have been used to study the controversial phylogenetic relationships between the species Dasypyrum villosum (L.) Candargy (2n=2x=14) and D. breviaristatum (Lindb. f.) Frederiksen (2n=4x=28). Using total genomic DNA from the two species as probes for in situ hybridization to chromosomes, we found that the pericentromeric regions of the chromosome arms of both species are similar, while distal regions show substantial differences. Two dispersed repetitive DNA sequences were isolated: pDbKB45 is distributed along the chromosomes but amplified in the subtelomeric regions of D. breviaristatum chromosomes, while pDbKB49, in both species, is less amplified in terminal regions. Size-separated restriction enzyme digests of DNA showed many repetitive fragments, but few in common between the two species. After probing Southern transfers with D. breviaristatum genomic DNA, all lanes showed similar hybridization patterns although one extra small band was evident in the D. breviaristatum lanes. In contrast, probing with D. villosum DNA showed very substantial differences between the two species. Genomic in situ hybridization to meiotic metaphases from an interspecific hybrid showed seven bivalents of D. breviaristatum origin and seven univalents from D. villosum. We also analysed the physical organization of 5S rDNA, 18S-25S rDNA and a tandemly repeated sequence from rye. Our data support an autotetraploid origin for D. breviaristatum, but its genome and that of D. villosum show extensive differences, so the tetraploid is unlikely to be directly derived from D. villosum.

Keywords

Restriction Enzyme Digest Hybridization Pattern Pericentromeric Region Subtelomeric Region Meiotic Metaphase 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • I. Galasso
    • 1
  • A. Blanco
    • 2
  • A. Katsiotis
    • 3
  • D. Pignone
    • 1
  • J. S. Heslop-Harrison
    • 3
  1. 1.C.N.R., Istituto del Germoplasma, Via G. Amendola 165/A, I-70126 Bari, ItalyIT
  2. 2.Istituto di Miglioramento Genetico delle Piante Agrarie, Università di Bari, Via G. Amendola 165/A, I-70126 Bari, ItalyIT
  3. 3.Karyobiology Group, Department of Cell Biology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UKGB

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