The first near-complete assembly of the hexaploid bread wheat genome,Triticum aestivum

Common bread wheat,Triticum aestivum, has one of the most complex genomes known to science, with 6 copies of each chromosome, enormous numbers of near-identical sequences scattered throughout, and an overall size of more than 15 billion bases. Multiple past attempts to assemble the genome have failed. Here we report the first successful assembly ofT. aestivum, using deep sequencing coverage from a combination of short Illumina reads and very long Pacific Biosciences reads. The final assembly contains 15,344,693,583 bases and has a weighted average (N50) contig size of of 232,659 bases. This represents by far the most complete and contiguous assembly of the wheat genome to date, providing a strong foundation for future genetic studies of this important food crop. We also report how we used the recently published genome ofAegilops tauschii, the diploid ancestor of the wheat D genome, to identify 4,179,762,575 bp ofT. aestivumthat correspond to its D genome components.