Dracaena spp. have a common name as Dragon tree or Dragon’s blood tree. Most Dragon trees have high values in gardening and horticulture, because they are evergreen, long-lived and slow-growing, and can thrive in extremely dry and arid environments. Importantly, some Dragon trees can secrete deep red resins, commonly known as Dragon’s blood or Sanguis Draconis, which is widely used as a wash to heal wounds or as a powder to block bleeding.
Dracaena cambodiana is the source plant of Dragon’s blood and has high ornamental values in gardening. Currently, this species is classified as the second-class state-protected species in the National Key Protected Wild Plants (NKPWP) of China. However, limited genomic data has hindered a more comprehensive scientific understanding of the processes involved in the production of Dragon’s blood and the related conservation genomics research.
In a study published in Scientific Data, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) and their collaborators reassembled a high-quality reference genome of D. cambodiana using both long-reads and short-reads data, which will be important for future studies in resource sustainable utilization and conservation biology of D. cambodiana.
Smples of D. cambodiana were collected and processed to achieve a chromosome-level and haplotype-resolved genome assembly by combining PacBio high-fidelity (HiFi) sequencing data and high-throughput chromosome conformation capture (Hi-C) data. The final assembled genome contains haplotype A (1,015.22 Mb) and haplotype B (1,003.13 Mb), with the contig N50 length of 6.23 Mb and 6.10 Mb, respectively.
The haplotype A and haplotype B genomes were annotated with 713.59 Mb (70.28%) and 701.17 Mb (69.90%) repetitive sequences, respectively. Furthermore, 27,361 protein-coding genes were identified in haplotype A genome, and 27,066 protein-coding genes were found in haplotype B genome.
“This study represents the first report of a chromosome-level and haplotype-resolved assembly of D. cambodiana genome. It will significantly contribute to the understanding of the mechanisms underlying Dragon’s blood formation, its evolutionary history, and conservation genomics, as well as its diverse applications in ornamental horticulture,” said YU Wenbin of XTBG.
