Ploidy determination of some yam species (Dioscorea spp.) by flow cytometry and conventional chromosomes counting

Chromosomes counting and flow cytometry were used for assessing the ploidy level of various yam accessions of the INRA collection located in Guadeloup e. About 85 different clones were evaluated in the D. alata and D. cayenens is-rotundata and four other wild species related to D. cayenensis-rotundata . All the studied clones fitted in 4x, 6x and 8x ploidy levels. No diploid clone was found. Chromosomes counts and flow cytometry data led to the same results. The flow cytometry histograms for D. cayenensis-rotundata were no t separated from those of its related wild species. Polyploidisation by fus ion of 2n+n gamets was found to be unlikely for the two species D. cayenens is-rotundata and D. alata. Moreover, these results lead to the conclusion t hat the D. cayenensis-rotundata cultigens and the wild species analysed in this study may belong to the same gene pool.