Integrative genomics of Oil-Camellia: From multi-omics dissection of key traits to mechanism-informed molecular breeding

Oil-Camellia, a prominent woody oil crop, holds immense economic and health significance due to its high-quality seed oil rich in unsaturated fatty acids and diverse secondary metabolites. Historically, the molecular breeding of this perennial tree has been challenged by its complex polyploid nature, long juvenile phase, and limited genomic information. Recent breakthroughs in sequencing technologies and bioinformatics have revolutionized Oil-Camellia genetics, yielding high-quality chromosome-level and even haplotype-resolved reference genomes for diploid and polyploid species. These genomic resources, coupled with multi-omics and population genetics analyses, have provided unprecedented insights into its genome evolution, oil biosynthesis pathways, flowering mechanisms, stress tolerance, and the genetic architecture underlying domestication. However, the key challenge is no longer simply to accumulate genomic datasets, but to integrate them into causal models and breeding-oriented strategies. This review critically synthesizes recent advances in Oil-Camellia genomics and genetic improvement, evaluating current evidence to propose a roadmap for translating molecular discoveries into practical breeding outcomes, thereby addressing key breeding challenges and fostering sustainable production.