Genomic advances in orphan and underutilized Brassicaceae crops and their wild relatives.

Orphan Brassicaceae crops, alongside other underutilized species and their wild relatives, represent an important but underexploited reservoir of genetic diversity with potential to enhance crop resilience, nutritional quality, and sustainable agriculture. These taxa include emerging oilseed, leafy vegetable, industrial, medicinal and stress-adapted species that harbor valuable traits such as tolerance to abiotic stresses, resistance to pests and diseases, improved seed and oil quality, and specialized bioactive compounds. Despite their potential, many of these species have received limited investment in breeding and genetic improvement compared to major Brassica crops. Recent advances in genomics and high-throughput sequencing have accelerated the development of genomic resources across Brassicaceae species, including chromosome-level genome assemblies, pan-genomes, and transcriptomic atlases. These resources have provided insights into genome evolution, gene family expansions, sub-genome dominance, and regulatory networks underlying key adaptive and agronomic traits. The increasing availability of genomic datasets has enabled molecular breeding approaches such as marker-assisted selection, genome-wide association studies, genomic selection, and genome editing. The close evolutionary relationships among Brassicaceae species further facilitate the transfer of knowledge and introgression of beneficial alleles from orphan and underutilized crops, as well as wild relatives, into cultivated Brassica species. Integration of genomic, transcriptomic, and multi-omics datasets enables the identification of candidate genes and regulatory pathways, guiding targeted breeding and accelerating the development of climate-resilient, nutrient-dense crops. This review highlights recent progress, challenges, and prospects for genomics-enabled breeding in orphan and underutilized Brassicaceae crops and their wild relatives.