Marie F. Sandrine, Simon Joly, Mickaël Bourge, Spencer Brown, Denis N. Omokolo


Yam (Dioscorea spp.) is an important food source in Africa, but diseases and storage pests hinder the African farmers to achieve high yields during the harvest. One important limitation to the genetic breeding of yam is the relatively unknown ploidy level variation within and among species.  The objective of this study was to determine the nuclear DNA content of 59 accessions representing four cultivated Dioscorea species collected from three regions of Cameroon (Adamawa, Centre and Southwest) using flow cytometry with propidium iodide staining. Our findings suggested the variation of the genome size both within and among the yams species. Nuclear DNA content (mean 2C-value) in studied yam collection ranging from 0.72 ± 0.013 pg in D. dumetorum to 2.801 ± 0.068 pg in D. cayenensis. The accessions could be divided into four different categories according to their, nuclear DNA content suggestive of four different ploidy levels. Ploidy variation was observed within all species with the exception of D. dumetorum that is likely diploid. This study contributes to a better understanding of the genome characteristics of yam species from Cameroon and may help to the genetic improvement of this important crop in the future.


Dioscorea, nuclear DNA content, Polyploidy, flow cytometry, genome

Full Text:



Ayensu, E. S. and D. G. Coursey. 1972. Guinea yams: the botany, ethno-botany, use and possible future of yams in West Africa. Econ. Bot. 26:301-318.

Arnau, G., A. Nemorin, E. Maledon, and K. Abraham. 2009. Revision of ploidy status of Dioscorea alata (Dioscoreaceae) by cytogenetic and microsatellite segregation analysis. Theor. Appl. Genet. 118: 1239–1249.

Baker, J. G. 1898. Dioscoreaceae, In: W.T. Thistelon-Dyer (ed.), Flora of tropical Africa. Lovell Reeve & Co., London.

Bennetzen, J.L. 2000. Transposable element contributions to plant gene and genome evolution. Plant Mol. Biol. 42:251-269.

Bennetzen, J.L. J. Ma and K.M. Devos 2005. Mechanisms of recent genome size variation in flowering plants. Ann. bot. 95: 127-132.

Brown, S.C. Devaux P, Marie D, Bergoumioux C, Petit P. 1991. Cytometrie en flux: Application à l’analyse de la ploidie chez les végétaux. Biofutur(octobre, Technoscope n 47) 105:1-14.

Coursey, D.G. 1967. Yams. Longman, London.

Dainou, O. C. Agbangla, J. Berthaud, S. Tostain. 2002. Le nombre chromosomique de base des espèces de Dioscorea constituent la section Enantiophyllum pourrait être égal à x=20. Quelques preuves. Ann. Sci. Agron. Benin 3:21-43.

Dansi, A. O. Daïnou, C. Agbangla, C. Ahanhanzo, S. Brown, H. Adoukonou-Sagbadja. 2005. Ploidy level and nuclear DNA content of some accessions of water yam (Dioscorea alata) collected at Savè, a district of central Benin. Plant Genet Resour Newsletter, 144: 20-23.

Dansi, A. H., D. Mignouna, M. Pillay and S. Zok, 2001a. Ploidy variation in the cultivated yams (Dioscorea cayenensis –Dioscorea rotundata complex) from Cameroon as determined by flow cytometry. Euphytica 119: 301–307.

Dansi, A. H., D. Mignouna, J. Zoundjihekpon, A. Sangare, R. Asiedu and N. Ahoussou. 2000. Using isozyme polymorphism for identifying and assessing genetic variation in cultivated Yam (Dioscorea cayenensis / Dioscorea rotundata complex) of Benin Republic. Genet. Resour. Crop. Evol. 47:371–383.doi: 10.1023/A: 1008718411962.

De wildeman, E. 1914. Notes sur les espèces Africaines du genre Dioscorea L. Bull. Jard. Bot. Etat, 4: 311-358.

Dolezel, J. 1997. Application of flow cytometry for the study of plant genomes. J. Appl. Genet. 38(3): 285–302.

Dolezel, J., J. Bartos, H.Voglmayr, J. Greilhuber. 2003. Nuclear DNA content of trait and human. Cytometry Part A 51A: 127-128.

Dolezel, J. and J. Greilhuber. 2010. Nuclear genome size: are we getting closer? Cytometry, 77A: 635–642.

Egesi, C. N., M. Pillay, R. Asiedu and J. K. Egunjobi. 2002. Ploidy analysis in water yam, Dioscorea alata L. germplasm. Euphytica 128:225-230.

Essad, S. 1984. Variation géographique des nombres chromosomiques de base et polyploïdie dans le genre Dioscorea à propos du dénombrement des espèces transversa Brown, pilosiuscuia Bert. et trifida L. Agronomie 4:611-617.

FIDA, 2003. Rapport de pré-évaluation du PNDRT. Volume I. Rome.

Galbraith, D.W., K.R. Harkins, J. M. Maddox, N.M. Ayres, D. P. Sharma and E. Firoozabady. 1983. Rapid flow cytometric analysis of the cell cycle in intact plant tissues. Science 220: 1049–1051.

Girma, G., K. E. Hyma, R. Asiedu, S. E. Mitchell, M. Gedil, and C. Spillane. 2014. Next-Generation Sequencing Based Genotyping, Cytometry and Phenotyping for Understanding Diversity and Evolution of Guinea Yams. Theor. Appl. Genet 127 (8): 1783–94.

Gregory, T.R. 2005. The C-value Enigma in Plants and Animals: A review of parallels and an Appeal for Partnership. Ann. bot. 95 :133-146.

Hamon, P., J. P. Brizard, J. Zoundjihékpon, C. Duperray and A. Borgel. 1992. Etude des index d’ADN de huit ignames (Dioscorea spp.) par cytométrie en flux. Can. J. Bot. 70: 996-1000.

Knuth, R.1924. Dioscoreaceae. In: A. Engler (ed.), Das Pflanzenreich IV.43.

Leitch, I.J., D. E. Soltis, P.S. Soltis and M. D. Bennett. 2005. Evolution of DNA amounts across land plants (embryophyta). Ann. Bot. 95: 207-217.

Lepers-Andrzejewski, S. Siljak-Yakovlev, S. Brown, S.C. Wong and M. Dron. 2011. Diversity and dynamics of plant genome size: an example of polysomaty from a cytogenetic study of Tahitian vanilla (Vanilla xtahitensis, Orchidaceae). Am. J. Bot. 98: 986-997.

Marie, D. and S.C. Brown. 1993. A cytometric exercise in plant DNA histograms, with 2C values for 70 species. Biol. Cell. 78: 41–51.

Muthamia, Z.K., A.B. Nyende, E.G. Mamati, M.E Ferguson and J. Wasilwa. 2014. Determination of ploidy among Yam (Dioscorea spp.) landraces in Kenya by flow cytometry. Afr. J. Biotechnol. 13 (3) 394-402.

Mignouma, H.D., R.A. Mank, T.H.N. Ellis, N.Van den bosch, R. Assiedu, S.Y.C. Ng, J. Peleman. 2002. A genetic linkage map of Guinea yam (Dioscorea rotundata Poir) based on AFLP markers. Theor. Appl. Genet. 105: 716-725.

Nemorin, A. J., E. David, E. Maledon, J. Nudol, Dalon, G. Arnau. 2013. Microsatellite and flow cytometry analysis to help understand the origin of Dioscorea alata polyploids. Ann. Bot. 112: 811–819.

Norman, P. E., P. Tongoona and P. E. Shanahan. 2012. Diversity in chromosome number and raphide morphology of yam (Dioscorea spp.) genotypes from Sierra Leone. Afr. J. Plant Sci. 6(4): 157-162.

Obidiegwu, J., J. Loureiro, E. Ene-Obong, E.Rodriguez, M. Kolesnikova-Allen, C. Santos, C. Muoneke and R. Asiedu. 2009a. Ploidy level studies on the Dioscorea cayenensis/Dioscorea rotundata complex core set. Euphytica 169:319–326.

Obidiegwu, J.E., E. Rodriguez, E.E.Ene-obong, J. Loureiro, C. Muoneke, C. Santos, M. Kolesnikova-Allen and R. Asiedu. 2009b. Estimation of the nuclear DNA content in some representatives of genus Dioscorea. Sci Res and Essays, 4(5): 448-452.

Obidiegwu, J., E. E. Rodriguez Ene-Obong, J. Loureiro, C. Muoneke Santos, C. M. Kolesnikova-Allen and R. Asiedu. 2010. Ploidy levels of Dioscorea alata L. germplasm determined by flow cytometry. Genet. Resour. Crop Evol. 57:351–356.

Otto, S.P.2007 The evolutionary consequences of polyploidy. Cell 131:452-463.

Orkwor, G.C, R. Asiedu and I.J. Ekanayake. 1998. Food Yams. Advances in Research, IITA and NRCRI, Nigeria. 249 pp.

Sharma, A.K. and D.N. De. 1956. Polyploidy in Dioscorea. Genetica, 28:112–120.

Scarcelli, N., O. Dainou, C. Agbangla, S.Tostain, J.L. Pham. 2005. Segregation Patterns of izozyme loci and microsatellite markers show the diploidy of African yam Dioscorea rotundata(2n=40).Theor.Appl.Genet. 111:226-232.

Zoundjihèkpon J (1993) Biologie de la reproduction et génétique des ignames cultivées de l’Afrique de l’Ouest, Dioscorea cayenensis-rotundata. Thèse de doctorat, Université Nationale de Côte d’Ivoire, Côte d’Ivoire.


  • There are currently no refbacks.

Copyright (c) 2014 Marie F. Sandrine, Simon Joly, Mickaël Bourge, Spencer Brown, Denis N. Omokolo

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Journal of Plant Breeding and Genetics
ISSN: 2305-297X (Online), 2308-121X (Print)
© EScience Press. All Rights Reserved.