During the last 12,000 years, different cultures around the world have domesticated cereal crops. Several studies investigated the evolutionary history and domestication of cereals such as wheat in the Middle East, rice in Asia or maize in America. The domestication process in Africa has led to the emergence of important cereal crops like pearl millet in Sahelian Africa. In this study, we used 27 microsatellite loci to analyze 84 wild accessions and 355 cultivated accessions originating from the whole pearl millet distribution area in Africa and Asia. We found significantly higher diversity in the wild pearl millet group. The cultivated pearl millet sample possessed 81% of the alleles and 83% of the genetic diversity of the wild pearl millet sample. Using Bayesian approaches, we identified intermediate genotypes between the cultivated and wild groups. We then analyzed the phylogenetic relationship among accessions not showing introgression and found that a monophyletic origin of cultivated pearl millet in West Africa is the most likely scenario supported by our data set.

No abstract

Allozyme variation was assessed in a collection of pearl millet cultivars derived from three different regions of traditional cultivation of this cereal in Tunisia and West African countries. Using starch gel electrophoresis, 11 loci corresponding to seven enzyme staining systems were identified. Important within-cultivar genetic diversity was detected. Genetic diversity within Tunisian cultivars was similar and was more pronounced than for West African ones. This result could be explained by the low level of the human selection characterizing the Tunisian cultivars. Most of the total genetic diversity is maintained within subregions suggesting little genetic differentiation. Cluster analysis did not reveal separate clusters for the various subregion cultivars. However the cluster analysis should help in the selection of interesting genotypes for future breeding programs.