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Genetic Resources and Crop Evolution

, Volume 55, Issue 5, pp 723–733 | Cite as

Diachronic (1979–2003) analysis of rice genetic diversity in Guinea did not reveal genetic erosion

  • Mamdou B. Barry
  • Jean Louis Pham
  • Sedou Béavogui
  • Alain Ghesquière
  • Nour AhmadiEmail author
Research Article

Abstract

Greater insight into the dynamics of genetic resources of crop plants is needed in order to pinpoint detrimental evolutionary patterns and draw up conservation priorities. Temporal evolution of rice genetic diversity was monitored in Maritime Guinea where subsistence-oriented agriculture prevails. Diachronic comparison was performed between samples collected in six villages during the 1979/1982-period and in 2003, based on the names and number of varieties inventoried and the polymorphism of microsatellite markers. The number of varieties appeared not to be comparable between the two dates, due to differences in the collection methods. The varietal composition had evolved very substantially between the two collection dates. Many long-duration varieties present in 1979/1982 had been abandoned and several improved varieties had been introduced. The mean number of alleles per locus and per accession was significantly higher in accessions collected in 2003. Pairwise comparisons of the mean number of alleles per locus in 1979/1982–2003 homonymous accession pairs indicated higher intra-accession diversity for the 2003 collections. Genetic differentiation, measured with the F ST values, was very high and significant for more than 80% of these pairs of accessions. The overall genetic differentiation between accessions from the two collections dates was also significant. Significant changes were also observed for allelic composition. However, alleles specific of each collection date had much lower frequency, compared to alleles common to the two collection dates. These results suggest that rice genetic diversity in Maritime Guinea has been maintained or even enhanced. Old collections of crop genetic resources are often not exhaustive enough to undertake perfect diachronic comparison. New methods to utilize this historical data for diversity monitoring are needed.

Keywords

Diversity Erosion Genetic resources Guinea Oryza Rice 

Notes

Acknowledgements

The French Ministry of Foreign Affairs and the Centre de Coopération en Recherche Agronomique pour le Développement provided funding for this research.

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Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Mamdou B. Barry
    • 1
  • Jean Louis Pham
    • 2
  • Sedou Béavogui
    • 1
  • Alain Ghesquière
    • 3
  • Nour Ahmadi
    • 4
    Email author
  1. 1.Institut de Recherche Agronomique de GuinéeConakryGuinea
  2. 2.UMR DGPC/IRDMontpellier Cedex 5France
  3. 3.Laboratoire Génome et Développement, IRDMontpellier Cedex 5France
  4. 4.UPR Peuplements de riz, CIRADMontpellier Cedex 5France

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