Chromosome-level genome assembly of watershield (Brasenia schreberi)

Abstract

Watershield (Brasenia schreberi) is an aquatic plant that belongs to the basal angiosperm family Cabombaceae. This species has been cultivated as an aquatic vegetable for more than 3000 years in East Asia, but the natural populations have greatly declined in recent decades and have become endangered in several countries of East Asia. In this study, by using PacBio long reads, Illumina short reads, and Hi-C sequencing data, we assembled the genome of B. schreberi, which was approximately 1170.4 Mb in size with a contig N50 of 7.1 Mb. Of the total assembled sequences, 93.6% were anchored to 36 pseudochromosomes with a scaffold N50 of 28.9 Mb. A total of 74,699 protein-coding genes were predicted in the B. schreberi genome, and 558 Mb of repetitive elements occupying 47.69% of the genome were identified. BUSCO analysis yielded a completeness score of 95.8%. The assembled high-quality genome of B. schreberi will be a valuable reference for the study of conservation, evolution and molecular breeding in this species.