Thanks to collaboration with the USDA-ARS (with funding provided by a NACA) we are working with colleagues at the USDA-ARS Forage Seed and Cereal Research Unit , Corvallis, OR; ARS, Raleigh, NC; and University of Minnesota - St. Paul, MN to characterize levels of barley seedling and adult plant resistance to stem rust UG99, identify the QTLs/genes responsible for the resistance phenotype, and to deploy resistance alleles in new genetic backgrounds.
In this project, we are developing UG99-resistant resistant germplasm. We are now into our second cycle of doubled haploid resistance allele inrogression and deployment.
Resistance donors: The donors are spring habit varieties, both hulled (TR02272, SB97197) and hull-less (MC0181-11, MC0181-31, SH98076, SH98073). This germplasm was developed by Drs. Brian Rossnalgel and Aaron Beattie (University of Saskatchewan) and Bill Legge (Agriculture and Agri-food Canada, Manitoba). Seed of each accession, harvested from plants verified for resistance phenotype, was provided by Dr. Brian Steffenson (University of Minnesota).
Adapted germplasm: The rpg4/Rpg5 donors were crossed with a range of germplasm from the OSU Barley Breeding Program, including winter and spring growth habit; hulled and hull-less; 2-row and 6-row; malting and food types.
123 doubled haploids were generated from 14 cross combinations among the Cycle 1 parents. All have been genotyped (Illumina 9K) and allele-specific genotyping for Rpg1, rpg4/Rpg5 is in progress. All have been phenotyped for UG99 stem rust at the Steffenson lab (University of Minnesota) and genotyped for stripe and leaf rust via the barley stripe rust NACA in collaboration with the Dubcovsky lab (UC Davis) and the Chen lab (ARS-Pullman). As of September, 2016 17/123 have been selected and characterized for resistance to UG99 stem rust, stripe rust, and leaf rust. Seed of the resistant accessions is available - ordering instructions.