Fonio Millets: Ethnobotany, Genetic Diversity and Evolution

Abstract

True fonio ( Digitaria exilis (Kipp.) Stapf) and black fonio ( D. iburua Stapf) are two domesticated millets of West Africa. These cereals are used as food and fodder as well as in brewing. They are persistent crops that do not require careful cultivation, and thrive under a range of difficult agricultural conditions. Fonio millets are amongst the least studied cereal crops, and there has been no study on the genetic diversity and evolution of these two millets. Random Amplified Polymorphic DNA (RAPD) approach was used in this study to assess the genetic diversity in fonio millets and to evaluate proposed hypotheses on their presumed wild progenitors. The results point to a very high genetic diversity in true fonio and to the possibility of multiple domestication or/and strong ecological or agriculture! differentiation. The genetic diversity in black fonio could not be assessed because of the availability of only one accession for the crop. The molecular data substantiate previous hypotheses that point to the morphologically allied species D. longiflora (Hatz) Pers. and D. ternata (A. Rich.) Stapf as possible progenitors of true and black fonios, respectively, and do not support the proposed genetic affinities between D. fuscescens (Presl) Henr. and true fonio. The study underscores the need for concerted effort to collect and conserve genetic resources of fonio millets and their wild progenitors since they are poorly represented in world gene banks.