Advances in breeding for cassava with low cyanogenic potential: Genetic, genomic, and biotechnological perspectives

Abstract Cassava ( Manihot esculenta Crantz) is a staple crop for millions of people worldwide and a vital source of food security and income in tropical and subtropical regions. However, its utilization is limited by the presence of cyanogenic glycosides (CGs), which release toxic hydrogen cyanide (HCN) and pose risks to human health. Reducing cyanide content while maintaining cassava’s agronomic performance remains a key breeding priority. In this review, we provide a comprehensive overview of the genetic variability underlying cyanide accumulation in cassava and summarize advances in breeding strategies aimed at lowering cyanogenic potential. We highlight findings from QTL mapping, genome-wide association studies, and the development of molecular markers linked to cyanide regulation. Additionally, we examine biotechnological approaches, including transgenic methods and recent applications of CRISPR/Cas-based genome editing, that directly target the CG biosynthetic pathway. Special attention is given to functional genomic studies that have identified candidate genes, regulatory networks, and transporters involved in cyanide biosynthesis, storage, and detoxification. We further discuss the implications of cyanide reduction for plant defense, nutritional quality, and food safety. Finally, we present perspectives on integrating genomic tools, molecular breeding, and genome editing to accelerate the development of cassava varieties with consistently low cyanogenic potential and improved safety for consumption.