Fonio millet genome unlocks African orphan crop diversity for agriculture in a changing climate

Sustainable food production in the context of climate change necessitates diversification of agriculture and a more efficient utilization of plant genetic resources. Fonio millet (Digitaria exilis) is an orphan African cereal crop with a great potential for dryland agriculture. Here, we establish high-quality genomic resources to facilitate fonio improvement through molecular breeding. These include a chromosome-scale reference assembly and deep re-sequencing of 183 cultivated and wild Digitaria accessions, enabling insights into genetic diversity, population structure, and domestication. Fonio diversity is shaped by climatic, geographic, and ethnolinguistic factors. Two genes associated with seed size and shattering showed signatures of selection. Most known domestication genes from other cereal models however have not experienced strong selection in fonio, providing direct targets to rapidly improve this crop for agriculture in hot and dry environments.

Fonio millet genome unlocks African orphan crop diversity for agriculture in a changing climate

Sustainable food production in the context of climate change necessitates diversification of agriculture and a more efficient utilization of plant genetic resources. Fonio millet (Digitaria exilis) is an orphan African cereal crop with a great potential for dryland agriculture. Here, we established high-quality genomic resources to facilitate fonio improvement through molecular breeding. These include a chromosome-scale reference assembly and deep re-sequencing of 183 cultivated and wild Digitaria accessions, enabling insights into genetic diversity, population structure, and domestication. Fonio diversity is shaped by climatic, geographic, and ethnolinguistic factors. Two genes associated with seed size and shattering showed signatures of selection. Most known domestication genes from other cereal models however have not experienced strong selection in fonio, providing direct targets to rapidly improve this crop for agriculture in hot and dry environments.

FONIO MILLET (DIGITARIA EXILIS) RESPONSE TO N, P AND K FERTILIZERS UNDER VARYING CLIMATIC CONDITIONS IN WEST AFRICA

SUMMARYFonio millet (Digitaria exilis), a small-grained cereal, plays an important role in food security in West Africa. As part of efforts to increase its productivity, we studied the effects of moderate levels of nitrogen (0, 15.0 and 30.0 kg N ha−1), phosphorus (0, 6.6 and 13.2 kg P ha−1) and potash (0, 12.5 and 25.0 kg K ha−1) fertilizers under varying climatic conditions. The three experimental sites at Bareng and Bordo in Guinea, and Cinzana in Mali, are representative of the distribution of fonio millet in West Africa. The average recorded grain yields were 1.51 ± 0.229, 1.08 ± 0.141 and 0.47 ± 0.182 t ha−1 in Bareng, Bordo and Cinzana, respectively. We observed a marginal to significant impact of N fertilization coupled, in Bordo, with a significant interaction with the P and K response. This interaction was highlighted by the limited effect of N without P or K fertilization or with the application of only one of these two major elements. Overall, N application as low as 15 kg ha−1 led to a 12–22% increase in production if the P and K applications were not limited. For better control over the risks associated with poor soil fertility and limited rainfall, it appeared to be more effective to apply moderate levels of N, P and K fertilizers to the fonio millet crop than a large amount of one of these nutrients.