Genetic diversity and nutritional variation in food crops in Ghana: A systematic review

Genetic diversity, which encompasses variations in gene sequences within a species, significantly impacts traits such as yield, nutrient content, resilience, and adaptability. This systematic review focuses on the nutritional profiles of key food crops: cassava ( Manihot esculenta ), tomato ( Solanum lycopersicum) , bambara groundnut ( Vigna subterranea ), and fonio ( Digitaria exilis ), following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and examining studies from the past 20 years. After a comprehensive search of four databases, 5 studies on cassava, 9 on tomato, 6 on bambara groundnut, and 1 on fonio were selected. The findings reveal notable nutritional variations based on genotype: cassava genotypes exhibited high range hydrogen cyanide levels and starch content; tomato genotypes varied moderately in lycopene levels, and bambara groundnut accessions showed moderate protein levels and polyunsaturated fatty acids (PUFA) content up to 51.6%. Although fonio exhibited limited genetic diversity, it maintained unique nutritional properties. Overall, the review indicates that utilising genetic diversity can aid in breeding nutrient-rich, resilient crops, enhancing food and nutrition security in resource-limited areas. • Genetic diversity influences nutritional traits in cassava, tomato, fonio, and bambara. • Cassava genotypes showed protein up to 18.5% and starch up to 95.1%. • Tomato genotypes varied in lycopene (1.74–7.96 mg/100 g) and vitamin C (12–86 mg/100 g). • Bambara accessions had PUFA content up to 51.6% and protein up to 22.4%. • PCA and clustering revealed distinct genetic-nutritional trait groupings in crops.