Long-read de novo assembly of the spekboom (Portulacaria afra) genome

Portulacaria afra (P. afra), or Spekboom as it is locally known, is a versatile evergreen shrubby succulent plant in the family Didiereaceae and endemic to the south-eastern parts of southern Africa. P. afra is not only known for its nutritional composition and its medicinal properties but has been shown to be pivotal in preventing desertification through limiting soil degradation. In addition, there is currently growing global attention on the use of P. afra as a garden ornamental. To address the lack of genetic resources for this increasingly important plant, we report on the de novo genome assembly of a Spekboom specimen of the Albany Thicket Biome using Oxford Nanopore Technology long-read sequencing, coupled with Illumina short-read polishing. Flow cytometry and k-mer analysis revealed the genome to be tetraploid and supports a haploid assembly size of ~ 0.68 Gb. BUSCO analysis revealed 99.3% complete BUSCO genes, indicative of the high gene completeness of the assembled genome.