Application of Genomic Selection to Increase the Rate of Genetic Gain of Intermediate Wheatgrass (Thinopyrum intermedium).

Intermediate wheatgrass (IWG) is a perennial species that is being domesticated for its potential as a grain, forage, and biofuel crop. While traditional phenotypic breeding and selection has improved several key production traits like lodging and shattering, much work remains to create a commercially viable product. Genomic technologies have the potential to increase the rate of genetic gain through faster breeding cycles and increased accuracy. Traditionally, it has required two years or more to complete one cycle of selection for this perennial crop. An enhanced breeding cycle using genotyping-by-sequencing markers was developed that allowed one cycle of selection to be completed each year. Additionally, genomic selection (GS) was applied to over 20 phenotypic traits for ~2200 plants in the breeding program at Salina, Kansas. The GS model accuracy, correlation between observed and model prediction, ranged from r=0.43 for spike yield to r=0.75 for flag leaf height. Taken together, genomic selection can aid researchers in increasing the rate of gain of IWG by reducing the breeding cycle and increasing selection accuracy.