DNA sequence-based mapping of the St. genome of Pseudoroegneria spicata (Pursh) A. Love versus wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.)

Authors: Wang, Richard; LI, XINGFENG - Shandong Agricultural University; Robbins, Matthew; Larson, Steven; Bushman, Shaun; Jones, Thomas; THOMAS, AARON - Utah State University

Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2020
Publication Date: 5/8/2020
Citation: Wang, R., Li, X., Robbins, M.D., Larson, S.R., Bushman, B.S., Jones, T.A., Thomas, A. 2020. DNA sequence-based mapping of the St. genome of Pseudoroegneria spicata (Pursh) A. Love versus wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). Genome. 63:445-457. https://doi.org/10.1139/gen-2019-0152.
DOI: https://doi.org/10.1139/gen-2019-0152

Interpretive Summary: Bluebunch wheatgrass (StSt; BBWG) is a forage grass for northern portion of the Intermountain region of North America. Expressed seuence tag derived simple sequence repeat (EST-SSR) markers had been developed for St genome in BBWG and some of them mapped to the St sub-genome in the tetraploid Snake River wheatgrass (StStHH). The St sub-genome in intermediate wheatgrass (JvsJvsJrJrStSt; IWG) had been characterized and mapped with EST-SSR markers and genotyping by sequencing (GBS) markers. Therefore, the St genome of diploid BBWG has not been mapped with EST-SSR and GBS markers until now. We mapped 230 EST-SSR and 3,468 GBS markers to 14 linkage groups belonging to seven homologous groups of the St genome. These markers allowed us to identify the seven St-subgenome linkage groups among 21 of IWG published by another group of scientists. The DNA sequences of our markers also enabled us to quantitatively assess the degree of homology, synteny, and collinearity between St genome and individual genome in bread wheat (A, B, and D) and barley (H). This work laid the foundation for future research that will ultimately benefit breeding of both forage and cereal crops of the tribe Triticeae.

Technical Abstract: Bluebunch wheatgrass ((referred as BBWG) [Pseudoroegneria spicata (Pursh) A. Love] is an important rangeland Triticeae grass native to western North American that is used for forage, conservation, and restoration,. It is a diploid with the basic St genome of Pseudoroegneria that occurs as a constituent genome, in combination with other basic genomes, in many polyploid Triticeae species, which serve as a gene reservoir for wheat improvement. Until now, the St genome in diploid Pseudoroegneria species has not been mapped. Using a mapping population of BBWG derived from (Anatone x Atomic)F1 x (Goldar x P-22)F1, we mapped 230 expressed seuence tag derived simple sequence repeat (EST-SSR) and 3,468 genotyping-by-sequencing (GBS) markers to 14 linkage groups (LGs; 7 each from each F1 parent). The 227 GBS markers obtained in this study that matched those in a previous study helped identify the unclassified 7 LGs of the St sub-genome among 21 LGs of Thinopyrum intermedium (Host) Barkworth & D.R. Dewey (intermediate wheatgrass, referred as IWG). Based on sequence homology of GBS markers between the St genome of BBWG and whole-genome sequences in bread wheat Triticum aestivum L.) and barley (Hordeum vulgare L.), the hormology, synteny, and collinearity of St genome to A, B, D, and H genomes were determined. This first-draft molecular map of St genome showed genome relationships between St and the four genomes in wheat and barley and will be useful in breeding cereal and forage crops.