Breeding Intermediate Wheatgrass for Grain Production
Publication: Plant Breeding Review, Volume 46, First Edition
This research paper details the improvement of breeding efforts with intermediate wheatgrass resulting from advances in molecular technologies, allowing scientists to focus on producing desirable agronomic traits to create an economically viable, high-yielding crop and model processes for new crop development.
Intermediate wheatgrass [IWG; Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] is a perennial grass with the unique distinction of having been, for more than 30 years, the target of active breeding for use as a grain crop for human consumption. Improving the grain production characteristics of a perennial forage grass to economically viable levels is a long-term endeavor that was undertaken because of the potential for profound benefits to farmers, humans, society, and the environment. Even before research as a perennial grain, IWG has had a history of improvement as a forage species, and as one of wheat’s closest perennial relatives it has also been used to transfer desirable traits into annual wheat. Since initial work in the 1980s, long-term breeding programs have been initiated in Kansas, Minnesota, and Utah (United States), Manitoba (Canada), and Uppsala (Sweden). Coupling advances in molecular technologies, many of these programs have harnessed the power of genomic selection and other cutting-edge tools to rapidly improve IWG. This has resulted in estimated gains of up to 8% per year for spike yield, and across eight breeding cycles grain yield has increased 9% per cycle, yet another 23 breeding cycles may be required before IWG yields are comparable to annual wheat. In addition to improving key domestication and agronomic traits, molecular research has provided a wealth of information about the genomic regions controlling trait expression through linkage mapping and genome-wide association studies. These results suggest that leveraging new molecular and breeding tools could potentially lead to de novo domestication of new crops in approximately 40 years or less.