Chromosome Research

, Volume 17, Issue 3, pp 291–304

Physical mapping of rDNA and heterochromatin in chromosomes of 16 Coffea species: A revised view of species differentiation

  • P. Hamon
  • S. Siljak-Yakovlev
  • S. Srisuwan
  • O. Robin
  • V. Poncet
  • S. Hamon
  • A. de Kochko
Article

DOI: 10.1007/s10577-009-9033-2

Cite this article as:
Hamon, P., Siljak-Yakovlev, S., Srisuwan, S. et al. Chromosome Res (2009) 17: 291. doi:10.1007/s10577-009-9033-2

Abstract

The chromosome organization among 15 wild diploid Coffea species and cultivated tetraploid C. arabica was determined by fluorochrome banding (CMA, DAPI) and double fluorescence in-situ hybridization (FISH) of 5S and 18S rDNA achieved on the same chromosome plates. Two to five chromosome pairs (plus one putative chromosome B) are marked. Overall, there are two SAT-chromosome pairs for East African species and one for the Malagasy and the West and Central African species. 18S rDNA loci are telomeric and strongly marked the SAT-chromosome pairs. Generally, only one pericentromeric 5S rDNA locus characterized East African species, while an additional minor locus co-localized with the 18S rDNA-SAT locus for the Malagasy species and West and Central African species. A combination of rDNA FISH plus CMA and DAPI banding patterns enables identification of almost all the species, even those for which the genetic or botanical status is still being discussed. C. arabica clearly appears to be an allotetraploid species, including one genome from East Africa and one from West and Central Africa. However, since the minor 5S rDNA-SAT locus present in West/Central African genomes is not detected, two evolutionary hypotheses could be put forward for C. arabica. Considering only the diploid species, global trends are obvious in rDNA signal patterns, genome size variations, and geographic distribution of the species, but there are no clear evolutionary trends. However, complex interactions between these factors and environmental growing conditions exist, which have resulted in loss and gain of rDNA loci and probably also in copy repeat number variations in each rDNA family.

Keywords

Coffea fluorescence in-situ hybridization fluorochrome banding genome organization ribosomal RNA genes 

Abbreviations

BAC

bacterial artificial chromosome

CCD

charge-coupled device camera

CMA

chromomycin A3

DAPI

4′,6 diamidino-2-phenylindole

FISH

fluorescence in-situ hybridization

GISH

genomic in-situ hybridization

HC

heterochromatin

NOR

nucleolar organizing region

SAT

satellite chromosome with a secondary constriction

SC

secondary constriction

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • P. Hamon
    • 1
  • S. Siljak-Yakovlev
    • 2
  • S. Srisuwan
    • 3
  • O. Robin
    • 2
  • V. Poncet
    • 1
  • S. Hamon
    • 1
  • A. de Kochko
    • 1
  1. 1.IRD, UMR DIAPCMontpellier cedex 5France
  2. 2.UMR 8079 UPS-CNRS-AgroParisTechOrsay cedexFrance
  3. 3.University Mae Fah LuangChiang RaïThailand

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