Highly Variable Regions in the Soybean Genome

The sequencing of the soybean Williams 82 genome has provided a common reference that has allowed rapid advancement of knowledge of the molecular basis of important soybean traits. However, while some important traits can be traced to a causative single nucleotide polymorphism within a highly conserved region, others have been traced to regions of the genome where there is extensive sequence and structural variation between soybean accessions. These traits are disproportionately those involved in resistance to pests and pathogens. For example, variation within clusters of canonical resistance genes is far higher than in most other parts of the protein-coding genome. An overview will be given of loci encoding nematode and aphid resistance and the emergence of common mechanistic and evolutionary themes. Emerging methods for whole genome sequencing, assembly and analysis of structural and copy number variation will be discussed as potential ways to obtain the sequences within the soybean population that are not captured by the Williams 82 reference sequence.