Chromosome-level genome assembly of <i>Helichrysum odoratissimum</i> , a medicinal plant from Southern Africa

Abstract

Helichrysum odoratissimum , a plant species native to Southern Africa, holds deep cultural significance and is widely used in traditional medicine. It is valued for its antimicrobial and anti-inflammatory properties and is cultivated and traded in South Africa due to its growing commercial relevance to the pharmaceutical and cosmetic industries. Despite its ecological and economic importance, genomic resources for this species remain limited. Here, we report a high-quality chromosome-level genome assembly for H. odoratissimum to facilitate investigations into its genetic basis of bioactivity, environmental adaptation, and taxonomic relationships. High-molecular-weight DNA extracted from leaf tissue was sequenced using Oxford Nanopore Technologies (ONT) long-read sequencing, and Hi-C proximity ligation data were generated to enable chromosome-scale scaffolding. The final assembly spans 2.4 Gb, with a scaffold N50 of 354 Mb, and was anchored and oriented into seven chromosomes, with 2,935 smaller scaffolds remaining unplaced. Assembly quality and completeness were evaluated using QUAST and BUSCO, and chromosomal structure was validated using Hi-C contact maps. This genome provides a foundational resource for functional genomics, conservation planning, molecular breeding, and the discovery of bioactive compounds underpinning the medicinal and commercial value of H. odoratissimum .