ABSTRACT
The strategy established by the IWGSC to achieve a reference sequence for the bread wheat genome relies on the ability to reduce the complexity of the wheat genome by working on individual chromosomes or chromosome arms in a so-called ‘chromosomebased approach’. In this approach, the sequencing challenge is reduced to the size of the chromosomes or chromosome arms that range from 224 Mb to 800 Mb and are comparable in size to other sequenced plant genomes (Doležel et al. 2007). In addition, working on individual chromosomes has the great advantage of eliminating the confounding effects of assembling similar sequences originating from the homologous chromosomes. Thus, the chromosome-based approach has practical benefits of reducing the size and complexity of sequencing projects, without sacrificing sample information content. It also has the advantage of permitting international collaboration through enabling chromosomes to be sequenced by individual teams, thereby facilitating cost sharing and rapid application of the data into the numerous wheat-breeding programmes around the world.
