Genotyping by reduced representation

The costs of sequencing increase substantially with larger genome sizes, but many important crop species, such as the cereals, have very large genomes.

Therefore a number of techniques have been developed to sequence only targeted regions of the genome – i.e. the genes – for example by filtering out highly repetitive regions (Barbazuk et al. (2005) BioEssays 27: 839-848).

These methods are becoming more and more cost-effective, such that it is now feasible to have nearly-complete genotypes of entire plant populations (at this writing the cost is approximately $20 per sample).

"Genotyping by sequencing" (GBS) allows a breeder to use genomic selection without developing any prior molecular tools such as markers and maps (Elshire et al. pers comm).

An example in grape is given in the open access journal PLoS One: Myles et al.(2010) PLoS One 5 (1): e8219 http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008219