Guinea yam ( Dioscorea spp.) wild relatives identified using whole plastome phylogenetic analyses

International audienceThe genus Dioscorea (Dioscoreaceae) contains several economically importantspecies for human consumption, medical and pharmaceutical uses. The phylogeny ofthis genus is not yet resolved. As a result, the relationships between cultivated yamsand their wild relatives are not well understood and this negatively impacts theunderstanding of cultivated yams' evolution. Here, we reconstructed the phylogeneticrelationships of the main African cultivated species with all West African species inorder to better circumscribe the Crop Wild Relatives of African yams. Completechloroplast genomes of 57 individuals representing all know 17 Dioscorea species fromWest Africa were reconstructed. Phylogenetic analyses recovered using neighbourjoining, maximum parsimony or maximum likelihood approaches were highlycongruent. We recovered six monophyletic groups corresponding to seven botanicalsections. All species were clearly distinct except within the Enantiophyllum section,where it was not possible to separate the two main cultivated species (D. rotundataand D. cayenensis) from their closest wild relatives (D. abyssinica, D. praehensilis andD. sagittifolia). Dioscorea baya was well differentiated but closely related to thecultivated clade. We therefore suggest its integration within the yam Crop Wild Relativecomplex