A chromosome-level genome assembly provides insights into Cornus wilsoniana evolution, oil biosynthesis and floral bud development

Abstract Cornus wilsoniana W. (C. wilsoniana) is a woody oil plant with high oil content and strong hypolipidemic effects, making it a valuable species for medicinal, landscaping, and ecological purposes in China. To advance genetic research on this species, we employed PacBio together with Hi-C data to create a draft genome assembly for C. wilsoniana. Based on an 11-chromosome anchored chromosome-level assembly, the estimated genome size was determined to be 843.51 Mb. The N50 contig size and N50 scaffold size were calculated to be 4.49 Mb and 78.00 Mb, respectively. Furthermore, 30,474 protein-coding genes were annotated. Comparative genomics analysis revealed that C. wilsoniana diverged with its closest species about 12.46 million years ago (Mya). Furthermore, the divergence between Cornaceae and Nyssaceae occurred over 62.22 Mya. We also found evidence of whole-genome duplication (WGD) events and whole-genome triplication gamma (WGT-γ), occurring at approximately 44.90 and 115.86 Mya. We further inferred the origins of chromosomes, which sheds light on the complex karyotype evolutionary history for C. wilsoniana. Through transcriptional and metabolic analysis, we identified two FAD2 homologous genes may play a crucial role in controlling the oleic to linoleic acid ratio. We further investigated the correlation between metabolites and genes and identified 33 MADS-TF homologous genes may affect flower morphology in C. wilsoniana. Overall, this study lays the groundwork for future research aimed at identifying the genetic basis of crucial traits in C. wilsoniana.