Ploidy variation in the cultivated yams (Dioscorea cayenensis-Dioscorea rotundata complex) from Cameroon as determined by flow cytometry

The ploidy levels of the twenty-two yam ( Dioscorea cayenensis-D. rotundata complex) cultivars within germplasm Cameroon Guinea yam were determined by flow cytometry. Three different ploidy levels (4x, 6x, 8x) were detected w ithin the samples analysed. Fifteen cultivars were tetraploids, five were h exaploids, and two were octoploids. The cultivar group EKOTO showed a high level of ploidy variation with tetraploid, hexaploid and octoploid cultivar s. The hexaploid nature of cultivars Dobnawo and Bilougnou supported the hy pothesis that they are hybrids between cultivars of the EKOTO group and eit her the KPE or BAKOKAE groups.