Research progress of omics technologies in forage breeding

Forages are essential to global agriculture and ecosystems, with the development of high-yield, high-quality varieties as a cornerstone of efficient agricultural practices. However, traditional genetic breeding methods, characterized by lengthy cycles and limited efficiency, fall short of meeting the demands of modern agriculture. In recent years, the rapid advancements in omics technologies, including genomics, epigenomics, transcriptomics, proteomics, and metabolomics, have significantly transformed forage research. These tools have deepened our understanding of the biological mechanisms underlying forage growth and development, aided in identifying essential genes and metabolic pathways, and accelerated the improvement of forage varieties. This review summarizes the applications and recent advances of various omics approaches in major forage species, including alfalfa (<i>Medicago sativa</i> L.), ryegrass (<i>Lolium perenne</i> L.), red clover (<i>Trifolium pratense</i> L.), white clover (<i>Trifolium repens</i> L.), and oat (<i>Avena sativa</i> L.). Additionally, we outline the advancements in these technologies for major crops and how we can learn from and apply them to improve forage yield, nutritional quality, and environmental adaptability, thereby establishing a theoretical foundation for the genetic improvement and molecular breeding of forages.