Skip to main content
Log in

Impact of farmer selection on yam genetic diversity

  • Research Article
  • Published:
Conservation Genetics Aims and scope Submit manuscript

Abstract

In the traditional yam agricultural system, by way of an ennoblement practice, farmers select tubers from the wild for cultivation. In order to assess the impact of that practice on the genetic diversity of yam, we studied the genetic structure of yams obtained after at least 3 years of ennoblement, to which farmers gave the name of traditional varieties. Cultivated yams do not always have the same genotype as homonymous traditional varieties. For the first time, we demonstrated selection by farmers through the ennoblement of genotypes found in neighbouring villages. Their adoption has a double impact: it allows an increase in the polyclonality of varieties and an indirect exchange of yam tubers between farmers. We also demonstrated that wild yams and hybrids between wild and cultivated yams are also selected. However, their adoption seems less frequent, suggesting selection and valuation of ennobled yams before integration into the cultivated pool. Finally, the adaptive advantage of wild and hybrid yams and their role in yam agrosystems are discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

Similar content being viewed by others

Notes

  1. Ennoblement was initially described under the unsuitable term of domestication.

References

  • Baco MN, Tostain S, Mongbo RL, Dainou O, Agbangla C (2004) Gestion dynamique de la diversité variétale des ignames cultivées (Dioscorea cayenensis-D. rotundata) dans la commune de Sinendé au nord Bénin. Plant Genetic Resour Newsl 139:18–24

    Google Scholar 

  • Balloux F, Lehmann L, de Meeûs T (2003) The population genetics of clonal and partially clonal diploids. Genetics 164:1635–1644

    PubMed  Google Scholar 

  • Balyejusa Kizito E, Chiwona-Karltun L, Egwang T, Fregene M, Westerbergh A (2007) Genetic diversity and variety composition of cassava on small-scale farms in Uganda: an interdisciplinary study using genetic markers and farmer interviews. Genetica 130(3):301–318

    Article  PubMed  Google Scholar 

  • Barnaud A, Deu M, Garine E, McKey D, Joly HI (2007) Local genetic diversity of sorghum in a village in northern Cameroon: structure and dynamics of landraces. Theor Appl Genet 114:237–248

    Article  PubMed  Google Scholar 

  • Belkhir K, Borsa P, Chikhi L, Raufaste N, Bonhomme F (2000) GENETIX 4.02, logiciel sous WindowsTM pour la génétique des populations. Laboratoire Génome, Populations, Interactions CNRS UMR 5000, Université de Montpellier II, Montpellier (France)

  • Brush SB (2000) The issues of in situ conservation of crop genetic resources. In: Brush SB (eds) Genes in the field. On farm conservation of crop diversity, pp 3–28. IPGRI, IDRC and Lewis Publisher. Rome, Italy

  • Brush SB, Meng E (1998) Farmers’ valuation and conservation of crop genetic resources. Genet Resour Crop Evol 45:139–150

    Article  Google Scholar 

  • Chaïr H, Perrier X, Agbangla C, Marchand JL, Dainou O, Noyer JL (2005) Use of cpSSRs for the characterisation of yam phylogeny in Benin. Genome 48:674–684

    Article  PubMed  Google Scholar 

  • Dansi A, Mignouna HD, Zoundjihékpon J, Sangare A, Asiedu R, Quin FM (1999) Morphological diversity, cultivar groups and possible descent in the cultivated yams (Dioscorea cayanensis/D. rotundata) complex in Benin. Genet Resour Crop Evol 46:371–388

    Article  Google Scholar 

  • Degras L (1986) L’igname: plante à tubercule tropicale. Maisonneuve et Larose et ACCT. Paris, France. 408 p

  • Dumont R (1998) Domestication des ignames en Afrique. In: Berthaud J, Bricas N, Marchand J-L (eds) Actes du séminaire international Cirad-Inra-Orstom-Coraf, Montpellier, France

  • Dumont R, Vernier P (2000) Domestication of yams (Dioscorea cayenensis-rotundata) within the Bariba ethnic group in Benin. Outlook Agric, London, UK 29(2):137–143

  • Dumont R, Dansi A, Vernier P, Zoundjihekpon J (2005) Biodiversité et domestication des ignames en Afrique de l’ouest: pratiques traditionnelles conduisant à Dioscorea rotundata. 120 p. Ed. Repères CIRAD

  • Elias M, Panaud O, Robert T (2000) Assessment of genetic variability in a traditional cassava (Manihot esculenta Crantz) farming system, using AFLP markers. Heredity 85:219–230

    Article  CAS  PubMed  Google Scholar 

  • Elias M, Penet L, Vindry P, McKey D, Panaud O, Robert T (2001) Unmanaged sexual reproduction and the dynamics of genetic diversity of a vegetatively propagated crop plant, cassava (Manihot esculenta Crantz), in a traditional farming system. Mol Ecol 10:1895–1907

    Article  CAS  PubMed  Google Scholar 

  • Evanno G, Regnault S, Goudet J (2005) Detecting the number of clusters of individuals using the software STRUCTURE: a simulation study. Mol Ecol 14:2611–2620

    Article  CAS  PubMed  Google Scholar 

  • FAO (2008) FAOSTAT database [online]. Available from http://www.fao.org/

  • Gibson RW, Lyimo NG, Temu AEM, Stathers TE, Page WW, Nsemwa LTH, Acola G, Lamboll R (2005) Maize seed selection by East African smallholder farmers and resistance to Maize streak virus. Ann Appl Biol 147(2):153–159

    Article  Google Scholar 

  • Glaubitz JC (2004) CONVERT: a user friendly program to reformat diploid genotypic data for commonly used population genetic software packages. Mol Ecol Notes 4:309–310

    Article  CAS  Google Scholar 

  • Goudet J (2001) FSTAT, a program to estimate and test gene diversities and fixation indices (version 2.9.3). Available from http://www.unil.ch/izea/softwares/fstat.html. Updated from Goudet (1995)

  • Halkett F, Simon JC, Balloux F (2005) Tackling the population genetics of clonal and partially clonal organisms. Trends Ecol Evol 20(4):194–201

    Article  PubMed  Google Scholar 

  • Hamon P, Toure B (1990) The Classification of Cultivated Yams (Dioscorea cayenensis-rotundata complex) of West Africa. Euphytica 47:179–187

    Google Scholar 

  • Jarvis DI, Hodgkin T (1999) Wild relatives and crop cultivars: detecting natural introgression and farmer selection of new genetic combinations in agrosystems. Mol Ecol 8:S159–S173

    Article  Google Scholar 

  • Louette D (2000) Traditional management of seed and genetic diversity: what is a landrace. In Brush SB (eds) Genes in the field. On farm conservation of crop diversity, pp 109–143. IPGRI, IDRC and Lewis Publisher. Rome, Italy

  • McLaughlin JF, Hellmann JJ, Boggs CL, Ehrlich PR (2002) Climate change hastens population extinctions. Proc Natl Acad Sci USA 99(9):6070–6074

    Article  CAS  PubMed  Google Scholar 

  • Mignouna HD, Dansi A (2003) Yam (Dioscorea ssp.) domestication by the Nago and Fon ethnic groups in Benin. Genet Resour Crop Evol 50(5):519–528

    Article  Google Scholar 

  • Nei (1987) Molecular evolutionary genetics. Columbia University Press. New York. US. 512 p

  • Orkwor GC, Asadu CLA (1998) Agronomy. In: Orkwor GC, Asiedu R, Ekanayake IJ (eds) Food yams: advances in research. NRCRI and IITA Ibadan, Nigeria

  • Perrier X, Jacquemoud-Collet JP (2006) DARwin software http://darwin.cirad.fr/darwin

  • Pertoldi C, Bijlsma R, Loeschcke V (2007) Conservation genetics in a globally changing environment: present problems, paradoxes and future challenges. Biodivers Conserv 16:4147–4163

    Article  Google Scholar 

  • Petit RJ, El Mousadik A, Pons O (1998) Identifying populations for conservation on the basis of genetic markers. Conserv Biol 12:844–855

    Article  Google Scholar 

  • Pritchard JK, Stephens M, Donnelly P (2000) Inference of population structure using multilocus genotype data. Genetics 155:945–959

    CAS  PubMed  Google Scholar 

  • Pujol B, David P, McKey D (2005) Microevolution in agricultural environments: how a traditional Amerindian farming practice favours heterozygosity in cassava (Manihot esculenta Crantz, Euphorbiaceae). Ecol Lett 8(2):138–147

    Article  Google Scholar 

  • Pujol B, Renoux F, Elias M, Rivale L, Mckey Doyle (2007) The unappreciated ecology of landrace populations: conservation consequences of soil seed banks in Cassava. Biol Conserv 136:541–551

    Article  Google Scholar 

  • Quiros CF, Ortega R, VanRaamsdonk LWD, Herrera-Montoya M, Cisneros P, Schmidt E, Brush SB (1992) Amplification of potato genetic resources in their center of Diversity: the role of natural outcrossing and selection by the Andean Farmers. Genet Resour Crop Evol 39:107–113

    Google Scholar 

  • Ramser J, Weising K, Lopez-Peralta C, Terhalle W, Terauchi R, Kahl G (1997) Molecular marker based taxonomy and phylogeny of Guinea yam (Dioscorea rotundata-D. cayenensis). Genome 40:903–915

    Article  CAS  PubMed  Google Scholar 

  • Risterucci AM, Grivet L, N’goran JAK, Pieretti I, Flament MH, Lanaud C (2000) A high density linkage map of Theobroma cacao L. Theor Appl Genet 101:948–955

    Article  CAS  Google Scholar 

  • Rosenberg NA, Woolf E, Pritchard JK, Schaap T, Gefel D, Shpirer I, Lavi U, Bonne-Tamir B, Hillel J, Feldman MW (2001) Distinctive genetic signatures in the Libyan Jews. Proc Natl Acad Sci USA 98(3):858–863

    Article  CAS  PubMed  Google Scholar 

  • Saitou N, Nei M (1987) The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4(4):406–425

    CAS  PubMed  Google Scholar 

  • Sardos J, McKey D, Duval MF, Malapa R, Noyer JL, Lebot V (2008) Evolution of cassava (Manihot esculenta Crantz) after recent introduction into a South Pacific Island system: the contribution of sex to the diversification of a clonally propagated crop. Genome 51:912–921

    Article  CAS  PubMed  Google Scholar 

  • Scarcelli N (2005) Structure et dynamique de la diversité d’une plante cultivée à multiplication végétative: le cas des ignames au Bénin (Dioscorea sp.). France, Université Montpellier II. Ph.D. thesis

  • Scarcelli N, Tostain S, Vigouroux Y, Agbangla C, Daïnou O, Pham JL (2006) Farmers’ use of wild relative and sexual reproduction in a vegetatively propagated crop. The case of yam in Benin. Mol Ecol 15:2421–2431

    Article  CAS  PubMed  Google Scholar 

  • Smale M, Bellon M, Aguirre Gomez JA (2001) Maize diversity, variety attributes, and farmers’choices in Southeastern Guanajuato, Mexico. Econ Dev Cult Change 50:201–225

    Article  Google Scholar 

  • Soleri D, Cleveland DA (2004) Farmer selection and conservation of crop varieties. Encyclopedia Plant Crop Sci 433–438

  • Tostain S, Okry FK, Baco NM, Mongbo RL, Agbangla C, Daïnou O (2003) La “domestication” des ignames Dioscorea abyssinica dans les sous-préfectures de Sinendé et de Banté au Bénin (Afrique de l’Ouest). Annales des Sciences Agronomiques du Bénin 4(1):33–54

    Google Scholar 

  • Tostain S, Scarcelli N, Brottier P, Marchand JL, Pham JL, Noyer JL (2006) Development of DNA microsatellite markers in tropical yam (Dioscorea sp.). Mol Ecol Notes 6:173–175

    Article  CAS  Google Scholar 

  • Tostain S, Agbangla C, Scarcelli N, Mariac C, Daïnou O, Berthaud J, Pham JL (2007) Genetic diversity analysis of yam cultivars (Dioscorea rotundata Poir) in Benin using simple sequence repeats (SSR) markers. Plant Genetic Resour Charact Util 5(2):71–81

    CAS  Google Scholar 

  • Vernier P, Orkwor G, Dossou RA (2003) Studies on yam domestication and farmers’ practices in Benin and Nigeria. Outlook Agric 32(1):35–41

    Article  Google Scholar 

  • Weir BS, Cockerham CC (1984) Estimating F-statistics for the analysis of population structure. Evolution 38:1358–1370

    Article  Google Scholar 

  • Zohary D (2004) Unconscious selection and the evolution of domesticated plants. Econ Bot 58(1):5–10

    Article  Google Scholar 

Download references

Acknowledgments

This research was supported by the Centre de Coopération Internationale en Recherche Agronomique pour le Développement and partly by the Beninese “Programme de Développement des Racines et Tubercules”. Part of this work was carried out using the resources of the Computational Biology Service Unit from Cornell University. We thank B. Fatondji and A. Bouet for their technical assistance. We gratefully acknowledge X. Perrier for his critical reading of the manuscript. Our greatest debts go to the farmers in the villages investigated in northern Benin for their interest in participating in our study and for providing us with valuable plant material.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to H. Chaïr.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chaïr, H., Cornet, D., Deu, M. et al. Impact of farmer selection on yam genetic diversity. Conserv Genet 11, 2255–2265 (2010). https://doi.org/10.1007/s10592-010-0110-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10592-010-0110-z

Keywords

Navigation