Hostname: page-component-5c6d5d7d68-xq9c7 Total loading time: 0 Render date: 2024-08-10T03:21:14.703Z Has data issue: false hasContentIssue false

Implications for in situ genetic resource conservation from the ecogeographical distribution of rice genetic diversity in Maritime Guinea

Published online by Cambridge University Press:  01 April 2007

M. B. Barry
Affiliation:
Institut de Recherche Agronomique de Guinée, PB 1523, Conakry, Guinea
J. L. Pham
Affiliation:
UMR DGPC /IRD, Av Agropolis, 34398 Montpellier Cedex 5, France
J. L. Noyer
Affiliation:
UMR PIA, CIRAD, Av Agropolis, 34398 Montpellier Cedex 5, France
B. Courtois
Affiliation:
UMR PIA, CIRAD, Av Agropolis, 34398 Montpellier Cedex 5, France
C. Billot
Affiliation:
UMR PIA, CIRAD, Av Agropolis, 34398 Montpellier Cedex 5, France
N. Ahmadi*
Affiliation:
UR Peuplements de riz, CIRAD, TA70/03, Av Agropolis, 34398 Montpellier Cedex 5, France
*
*Corresponding author. E-mail: ahmadi@cirad.fr

Abstract

Genetic resource conservation is widely acknowledged as important. The implementation of conservation requires an insight into the distribution of genetic diversity at the scale of small regions or villages. We present an analysis of rice diversity at such a scale, in a region where traditional farming still prevails. Regional allelic diversity was comparable to that noted worldwide for Asian rice (Oryza sativa), but not as high for African rice (O. glaberrima). Each village pooled more than half of the regional allelic diversity. Genetic differentiation between varieties from the same village accounted for 70% of the regional variation. The differentiation associated with lowland and upland rice-growing ecosystems was 23%, while that associated with differences between villages within the same ecosystem was 7%. In the upland ecosystem, geographical distance had a significant effect on the FST between pairs of villages. In the lowland ecosystem, differences in soil salinity between villages affected FST. Genetic diversity within a single village may have up to three components: an ancient glaberrima component shared with neighbouring or ethnically related villages; a relatively ancient sativa component which was hardly or no longer shared with other villages due to local differentiation; and a recently introduced sativa component shared with other villages. Genetic resource conservation could be achieved, in terms of allelic diversity, through stratified sampling according to described genetic differentiation factors, whereas current farming systems must be preserved to ensure conservation of the diversity of allelic associations.

Type
Research Article
Copyright
Copyright © NIAB 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Altieri, MA and Merrick, LC (1987) In situ conservation of crop genetic resources: maintenance of traditional farming systems. Economic Botany 41: 8696.Google Scholar
Barry, MB, Pham, JL, Noyer, JL, Courtois, B and Ahmadi, N (2006c) Genetic diversity of the two cultivated rice species (O. sativa & O. glaberrima) in Maritime Guinea. Evidence for interspecific recombination. Euphytica (forthcoming).CrossRefGoogle Scholar
Beavogui, L, Diallo, A and Dillo, M (2000) Affinage du zonage agro-écologique de la Guinée martitime. Conakry, Guinea: IRAG.Google Scholar
Bellon, M (2003) Conceptualising interventions to support on-farm genetic resource conservation. World Development 32: 159172.CrossRefGoogle Scholar
Bellon, MR, Pham, JL and Jackson, MT (1997) Genetic conservation: a role for rice farmers. In: Maxted, N, Ford-Lloyd, BV and Hawkes, JG (eds) Plant Conservation: The In Situ Approach. London: Chapman and Hall; Rome: International Plant Genetic Resources Institute, pp. 263289.Google Scholar
Bezançon, G (1995) Riziculture traditionnelle en Afrique de l'Ouest: valorisation et conservation des ressources génétiques. Journal d'Agriculture Traditionnelle et de Botanique Appliquée 37: 324.CrossRefGoogle Scholar
Brush, SB (1999) The issues of in situ conservation of crop genetic resources. In: Brush, S (ed.) Genes in the Field. Rome, Ottawa: International Plant Genetic Resources Institute; Lewis publishers, pp. 3–26.Google Scholar
Caughley, G (1994) Directions in conservation biology. Journal of Animal Ecology 63: 215244.CrossRefGoogle Scholar
Cox, T and Wood, D (1999) The nature and role of crop biodiversity. In: Lenné, W (ed.) Agrobiodiversity: Characterization, Utlization and Management. London: CAB International, pp. 35–37.Google Scholar
Excoffier, L, Smouse, P and Quattro, J (1992) Analysis of molecular variance inferred from metric distances among DNA haplotypes: application to human mitochondrial DNA restriction data. Genetics 131: 479491.CrossRefGoogle ScholarPubMed
Garris, A, Tai, T, Coburn, J, Kresovich, S and McCouch, S (2005) Genetic structure and diversity in Oryza sativa L. Genetics 169: 16311638.CrossRefGoogle ScholarPubMed
Ghesquière, A and Second, G (1983) Polymorphisme enzymatique et évolution d'Oryza sativa en Afrique. Electrophorère et taxonomie. Paris: Société Zoologique de France, pp. 8390.Google Scholar
Hanski, I and Gyllenberg, M (1993) Two general metapopulation models and the core-satellite species hypothesis. The American Naturalist 142: 1741.Google Scholar
Hawkes, JR (1983) The Diversity of Crop Plants. Cambridge, MA: Harvard University Press.CrossRefGoogle Scholar
International Plant Genetic Resources Institute(1993) Diversity for Development: The Strategy of the International Plant Genetic Resources Institute. Rome: IPGRI.Google Scholar
Jarvis, D and Hodgkin, T (2000) Farmer decision making and genetic diversity. In: Brush, SB (ed.) Genes in the Field: On-farm Conservation of Crop Diversity. Rome: IDRC/IPGRI, pp. 261278.Google Scholar
Kiambi, D, Newbury, H, Ford-Lloyd, B and Dawson, I (2005) Contrasting genetic diversity among Oryza longistaminata (A. Chev et Roehr) populations from different geographic origins using AFLP. African Journal of Biotechnology 4: 308317.Google Scholar
Kochko, AD (1987) Isozyme variability of traditional rice Oryza sativa (L.) in Africa. Theoretical and Applied Genetics 73: 675682.Google Scholar
Lawton, J (1994) What do species do in ecosystems? Oikos 71: 367374.CrossRefGoogle Scholar
Liu, K and Muse, S (2001–2004) PowerMarker: new genetic data analysis software,http://www.powermarker.net.Google Scholar
Luce, C, Noyer, JL, Tharreau, D, Ahmadi, N and Feyt, H (2001) The use of microsatellite markers to examine the diversity of the genetic resources of rice (Oryza sativa) adapted to European conditions. Acta Horticulturae 546: 221235.Google Scholar
Maxted, N, Ford-Lloyd, BV, Hawkes, JG (eds) (1997) Plant Conservation: The In Situ Approach. London, Rome: Chapman and Hall. International Plant Genetic Resources Institute.Google Scholar
McKey, D, Emperaire, L, Elias, M, Pinton, F, Robert, T, Desmoulière, S and Rival, L (2001) Gestions locales et dynamiques régionales de la diversité variétale du manioc en Amazonie. Genetics Science Evolution 3: 465490.CrossRefGoogle Scholar
Nkongolo, K and Nsapato, L (2003) Genetic diversity in Sorghum bicolor (L.) Moench accessions from different ecogeographical regions in Malawi assessed with RAPDs. Genetic Resources and Crop Evolution: 50.Google Scholar
Olfield, MJ and Alcorn, JB (1987) Conservation of traditional agroecosystems. Bioscience 37: 199208.Google Scholar
Perrier, X, Flori, A and Bonnot, F (2003) Data analysis methods. In: Hamon, P, Seguin, M, Perrier, X and Glaszmann, JC (eds) Genetic Diversity of Cultivated Tropical Plants. Montpellier: Enfield Science Publishers, pp. 43–76.Google Scholar
Pimm, S, Jones, H and Diamond, J (1988) On the risk of extinction. The American Naturalist 132: 757785.CrossRefGoogle Scholar
Risterucci, AM, Grivet, L, N'Goran, JAL, Pierett, I, Flament, MH and Lanaud, C (2000) A high-density linkage map of Theobroma cacao L. Theoretical and Applied Genetics 101: 11761182.CrossRefGoogle Scholar
Saitou, N and Nei, M (1987) The neighbor-joining method: a new method for reconstructing phylogenetic trees. Molecular Biology and Evolution 4: 406–425.Google Scholar
Schneider, S, Roessli, D and Excoffier, L (2000) Arlequin: A Software for Population Genetics Data Analysis. Geneva: Genetics and Biometry Laboratory, Department of Anthropology, University of Geneva.Google Scholar
Second, G (1982) Origin of the genetic diversity of cultivated rice (Oryza spp.): study of the polymorphism scored at 40 isozyme loci. Japanese Journal of Genetics 57: 25–57.Google Scholar
Second, G (1985) Relations évolutives chez le genre Oryza et processus de domestication. Paris: ORSTOM.Google Scholar
Semon, M, Nielsen, R, Jones, P and McCouch, S (2004) The population structure of cultivated Oryza glaberrima (Steud): evidence for elevated levels of LD caused by admixture with O. sativa and ecological adaptation. Genetics 169: 6391647.Google Scholar
Wood, D and Lenné, JM (1999) Agrobiodiversity: Characterization, Utilization and Management. Wallingford, UK: CABI Publishing.Google Scholar
Wright, S (1978) Evolution and the genetics of populations. Variability Within and Among Natural Population. Chicago: University of Chicago Press.Google Scholar
Yu, S, Xu, W, Geo, W and Song, Xu (2003) Molecular diversity and multilocus organization of the parental lines used in the International Rice Molecular Breeding Program. Theoretical and Applied Genetics 108: 131–140.CrossRefGoogle ScholarPubMed