Characterising diversity in the Brassica genomes

The genome sequence of an organism provides the basis for gene discovery, the analysis of genetic variation and the association of genomic variation with heritable traits. Genome sequence variation can vary from single nucleotide polymorphisms, insertions/deletions to presence/absence of large regions or rearrangements. Second generation sequencing technologies and applied bioinformatics tools can provide an unprecedented insight into genome structure and variation, with applications for understanding the evolution of Brassica species and advancing crop breeding strategies. Advances in data production and bioinformatics capability now make the resequencing of complex polyploid genomes routine. This provides the opportunity to expand genomics from gene and molecular genetic marker discovery to developing a broader understanding of the role of adaptation and selection in diversity. This, in turn, enables comparative genomic approaches to truly comprehend the effect of diversity on genome structure and how this impacts on the form and function of organisms, their growth and development, and response to environment, pests and diseases. The sequencing and re-sequencing of different Brassica varieties has given researchers an unprecedented opportunity to identify genome wide variation. Bioinformatics tools have been produced and applied to interrogate and annotate this abundant data, and genome wide variation has been integrated with genetic maps and phenotypic information. The Brassica genomes, when combined with genome diversity information provide an insight into the evolution of these important crop plants and their wild relatives. Together this information can be used to advance breeding of improved varieties with enhanced agronomic traits.