|HIJMANS, ROBERT - University Of California, Davis|
|Esvelt Klos, Kathy|
|GIRONELLA, ANN INEZ - Idaho State University|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2018
Publication Date: 12/27/2018
Citation: Bonman, J.M., Bockelman, H.E., Hijmans, R.J., Hu, G., Esvelt Klos, K.L., Gironella, A.N. 2018. Evaluation of grain ß-glucan content in barley accessions from the USDA National Small Grains Collection. Crop Science. 59(2):659-666. https://doi.org/10.2135/cropsci2018.10.0606.
Interpretive Summary: ß-glucan (BG) is a type of soluble fiber found in barley that has human health benefits. To develop new cultivars for the food industry, barley breeders seek to increase BG content in barley grain. The barley accessions maintained in the USDA National Small Grains Collection (NSGC) are a resource for plant breeders and most have been assessed for their BG content. However, the BG results are difficult to interpret because they were generated from seed grown in 15 different years. We developed a way to classify BG content within each year. We then analyzed the relationship of BG content with the geographic origin of accessions and other barley descriptors and verified the analysis with two replicated field experiments using a total of 829 accessions. Accessions originating from Asia and Africa had higher frequencies of high BG content accessions compared to those from Europe and the Americas. Two row accessions were more often classified as high BG content compared to six row types. Our results will help breeders identify barley accessions from the NSGC that can be useful for further breeding work.
Technical Abstract: The content of (1->3, 1->4)-ß-glucan (BG) in barley has become a breeding target due to the human health benefits of BG. More than 20,000 barley accessions from the USDA National Small Grains Collection (NSGC) have been assayed for BG content and the data recorded in the Germplasm Resources Information Network (GRIN). This study classified barley accessions as high or low BG content using the GRIN data, analyzed the relationship of BG content with the geographic origin of accessions and other barley descriptors, and verified the analysis with two replicated field experiments using a total of 829 accessions. BG content varied with geographic origin and spikerow type. Accessions from Asia and Africa had higher frequencies of high BG content accessions and those from Europe and the Americas had higher frequencies of low BG content accessions. Two row accessions were more often classified as high BG content compared to six row types. There was no significant relationship between accession improvement status (e.g. landrace versus cultivar or breeding line) and BG content. The geographic differences among barley accessions likely correspond to the ecogeographic classification of barley and end-use needs that vary by origin. GRIN data should be expanded to include classification of relative BG content to make the data more readily useful to plant breeders.