Abstract

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, human 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.

Keywords

Breeding; Domestication; Ecosystem services; Forage; Genomic selection; Intermediate wheatgrass; Mapping; Perennial grain; Quantitative trait locus; Thinopyrum intermedium

Published in

Plant Breeding Reviews
2023, number: 46, pages: 119-217 ISBN: 9781119874126, eISBN: 9781119874157
Publisher: Wiley Blackwell

SLU Authors

• Westerbergh, Anna

  • Department of Plant Biology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science
Genetics and Breeding


Permanent link to this page (URI)

https://res.slu.se/id/publ/129500