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.

Beyond NGS data sharing for plant ecological resilience and improvement of agronomic traits

“…Lu et al . 8 conducted a study focusing on the genome assembly of watershield ( Brasenia schreberi ), an aquatic plant, historically cultivated as a vegetable in East Asia. Employing PacBio long reads, Illumina short reads, and Hi-C sequencing techniques, they successfully assembled the 1170.4 Mb genome, with 93.6% of it anchored to 36 pseudochromosomes, thus representing significant advancements in understanding the genetic makeup of this endangered aquatic plant species.…”

Draft genome of Brasenia schreberi, a worldwide distributed and endangered aquatic plant

“…Brasenia schreberi contains allelopathic components that can be used in the management of aquatic weeds [ 7 ]. As important values in taxonomy, ecology, and economy and in its endangered situation, a genome assembly was published previously [ 8 ] for its better conservation and breeding. However, given its wide distribution worldwide and existing substantial genetic diversities [ 3 , 9 ], we present an alternative B .…”

“…However, our assembly displayed a completeness comparable to the previously reported B . schreberi assembly [ 8 ], which showed 89.0 and 95.9% completeness using BUSCO in the Eudicots and Embryphyta databases, respectively, and 91.3% and 97.0% completeness using compleasm in the Eudicots and Embryphyta databases, respectively. Nevertheless, because this previous assembly did not remove duplications from the assembly [ 43 ], some assembly errors may exist for gene prediction.…”