Revealing Ghana's unique fonio genetic diversity: leveraging farmers knowledge for sustainable conservation and breeding strategies

Genetic diversity analysis is pivotal for optimizing the use of genetic resources and deploying conservation strategies in the face of global changes. This is important for essential indigenous species often neglected by research. This research was carried out to examine the pattern of genetic diversity and structure among fonio (Digitaria exilis (Kippist) Stapf) accessions in Ghana. Following farmer surveys and collection efforts in key fonio-growing regions of Ghana, we amassed a comprehensive collection of 176 fonio accessions from 165 farmers across 24 communities. Farmer surveys identified 21 distinct cultivars cultivated predominantly for home consumption, averaging six cultivars per ethnic group. Out of the 176 accessions, 140 underwent genotyping using 14 simple sequence repeat (SSR) nuclear markers which revealed greater diversity within cultivars (58.5%) compared to between cultivars (16.8%) following molecular variance analysis. The organizational pattern of fonio genetic diversity was significantly influenced by farmer-specific cultivars, emphasizing the role farmers play in long-term preservation of fonio genetic diversity. Future strategies for the management, conservation, and utilization of fonio genetic resources in Ghana should incorporate traditional farming practices. Our findings further revealed the uniqueness of Ghanaian fonio genetic diversity, despite a smaller cultivation area compared to the global diversity. This shows the contribution of the interaction between the crop, environment and societal factors to the distinct genetic makeup observed in the Ghanaian fonio population. The observed genetic diversity can be exploited to identify and select genetically distinct individuals to develop tailored product profiles within fonio breeding programs for diverse market segments.