Improved Brassica rapa reference genome by single-molecule sequencing and chromosome conformation capture technologies

Genomes: a new map of field mustard A detailed third-generation genome sequence has been published for Brassica rapa, which includes crops such as napa cabbage, turnips, and bok choy. Older technologies required researchers to stitch together many short sequences. Recently developed methods produce long, high-fidelity sequences. Xiaowu Wang at the Chinese Academy of Agricultural Science and the Shandong Provincial Key Laboratory of Protected Vegetable Molecular Breeding, Hongkun Zheng at Biomarker Technologies Corporation, and coworkers in China assembled the new version using 1498 sequences, compared to the 96,883 needed for the previous version. These methods provide a significant improvement in the level of detail, and permit mapping of highly repetitive regions, which were nearly impossible to map using older methods. The new sequence will aid breeding efforts, permit better comparisons with other Brassica genomes, and improve our understanding of genome evolution.