Modelling current agro-ecological zones for the cultivation of Dioscorea dumetorum (Kunth) Pax, a neglected and underutilized yam species in Benin (West Africa)

Abstract

Yam species (Dioscorea spp.) constitute important staple foods for local communities in Sub-Saharan in Africa. Among yam species, Dioscorea dumetorum (Kunth) Pax, commonly consumed, has been reported to be among the most nutritious and well-appreciated local resource although it remains neglected and underutilized species in Benin. Here, we combined occurrence records and environmental data (bioclimatic and soil data) in ecological niche models to assess the suitable areas for the two locally acknowledged varieties of the species: the cultivated and the wild varieties. Results showed that the potential cultivable area of the cultivated variety is twofold, the one of the wild variety. Seven and five of the eight agro-ecological zones of Benin are potentially suitable for the cultivation of the cultivated variety and the wild variety, respectively. Differences in the two varieties of ranges could result from the adaptation of each variety to local conditions reinforced by intrinsic characteristics of each variety. These results constitute an important step towards scaling up the species valorization while developing conservation programs for both varieties. Further genetic investigation and field experiments could shed light on the origin of the differences between these two forms.