Genome assembly of the rare and endangered Grantham's camellia, Camellia granthamiana

The Granthams camellia (Camellia granthamiana Sealy) is a rare and endangered tea species that is endemic to southern China, and was first discovered in Hong Kong in 1955. Despite its high conservation value, genomic resources of C. granthamiana remain limited. Here, we present a chromosome-scale draft genome of the tetraploid C. granthamiana (2n = 4x = 60) using a combination of PacBio long read sequencing and Omni-C data. The assembled genome size is [~]2.4 Gb with most sequences anchored to 15 pseudochromosomes that resemble a monoploid genome. The genome is of high contiguity, with a scaffold N50 of 139.7 Mb, and high completeness with a 97.8% BUSCO score. Gene model prediction resulted in a total 76,992 protein-coding genes with a BUSCO score of 85.9%. 1.65 Gb of repeat content was annotated, which accounts for 68.48% of the genome. The Granthams camellia genome assembly provides a valuable resource for future investigations on its biology, ecology, phylogenomic relationships with other Camellia species, as well as set up a foundation for further conservation measures.