Brassica nigra genome sequencing and assembly

The genome of the diploid Brassica nigra (Brassica B genome) was sequenced using a hybrid Illumina / Roche 454 sequencing approach from multiple libraries ranging in insert size. The assembly of 447Mb represents 78% of the predicted genome size. Genotyping-by-sequencing was used to anchor almost 82% of the assembled scaffolds to eight pseudo-chromosomes, named according to Lagercrantz (1998). Over 50,000 genes were annotated with 41% of the genome predicted to be repetitive. Brassica nigra separated earlier in the lineage than its relative’s B. oleracea (C genome) and B. rapa (A genome), which is reflected in multiple major chromosomal rearrangements that distinguish the Brassica B genome from the A and C.