Thanks to USDA-ARS NACA funding, 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 germplasm resistant to race TTKSK (UG99) of stem rust. By leveraging resources provided by the Barley Stripe Rust NACA, we are also assessing this germplasm for resistance to other rusts. We are now into our fifth cycle of doubled haploid resistance allele introgression and deployment.
On this page, you can access a chronological listing of projects and reports.
To access phenotype and genotype data, please send a request* for access to the Box folder containing a treasure trove of phenotype and genotype data.
Resistance donors: The donors were spring habit varieties, both hulled (TR02272, SB97197) and hull-less (MC0181-11, MC0181-31, SH98076, SH98073). This germplasm was developed by Drs. Brian Rossnagel 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. Genotype data were generated using the Illumina 9K and allele-specific primers for Rpg1 and rpg4/Rpg5. Phenotype data for UG99 resistance at the seedling stage were generated at the Steffenson lab (University of Minnesota).
Resistance donors: The donors were TTKSK-resistant selections from Cycle I.
Adapted germplasm: The Cycle I selections were crossed with winter/facultative malting and multi-use germplasm from the OSU program and the UC Davis Program.
384 doubled haploids were generated. The DH and parents were genotyped with the Illumina 50K and allele-specific genotyping was conducted for rpg4/Rpg5. The array was phenotyped for TTKSK resistance at the seedling stage and for QCC-J resistance at the adult stage at the Steffenson lab (University of Minnesota).
Cycle III: An array of 373 doubled haploids was generated from crosses among OSU germplasm that exhibited resistance to race TTKSK at the seedling stage. None of this germplasm amplified for rpg4/Rpg5. These are, therefore, potential new sources of resistance to TTKSK. These resistance donors were crossed with winter/facultative malting and winter/facultative malting barley germplasm from OSU Barley Breeding Program. Stem rust at the seedling stage was assessed under controlled environment conditions at University of Minnesota. The array was genotyped at the USDA-ARS Fargo Genotyping Lab using using the Illumina 50K SNP platform.
Cycle IV: An array of 661 genotypes (primarily doubled haploids and their parents) was assembled for phenotyping and genotyping. The array consists of germplasm from five sources within the OSU barley program (1) elite malting 2-row winter and facultative types with resistance to multiple diseases and potential for brewing and distilling end-uses; (2) 2-row winter and facultative selections developed for the US Wheat and Barley Scab Initiative with potential malting quality; (3) 2-row and 6-row winter and facultative selections from the USDA-OREI fall naked diversity panel with potential multi-purpose end uses; (4) 2-row winter and facultative selections from the AMBA LTT panel; (5) 2-row and 6-row winter selections from Cycle 2; (5) 2-row winter, facultative, and spring selections from Cycles 1 and 2.
Cycle V: An array of 267 genotypes (primarily doubled haploids and their parents) consists of germplasm from two sources within the OSU barley program (1) elite malting 2-row winter and facultative types with resistance to multiple diseases and potential for brewing and distilling end-uses and (2) naked 2-row winter and facultative naked selections with potential for malting and downstream uses. The array was genotyped with the 50K Illumina SNP platform at the USDA-ARS lab at Fargo, ND. A subsample of winter growth habit entries was assessed in the in the USDA/ARS trials in Africa.
Cycle VI: A selection of 186 experimental lines and six checks from the 903 experimental doubled haploid lines represented in the 2021-2022 OSU barley program fall-planted malting trials. The original population includes lines from 16 distinct crosses and was phenotyped for agronomic traits and prevailing diseases in the 2021-2022 season. This 186-line subset was selected both for the identification of fall planted barley lines with good malting capability and for the identification of novel resistance to barley yellow dwarf virus (BYDV). Of these 186 lines, 93 were selected based on positive agronomic performance as well as resistance to BYDV. The other 93 lines were selected based on their susceptibility to BYDV for the purposes of identifying disease resistance genes in a genome-wide association study. Of the 16 founding crosses, lines representing 15 of them were selected for the Cycle VI population. The Cycle VI population will be planted at Corvallis, Oregon and Davis, California in the 2022-2023 season for BYDV, stripe rust, and other prevailing diseases. The current strategy for assessing stem rust at the adult plant stage, which is currently not possible at US locations, will be to assess a subsample of winter growth habit accessions in the USDA/ARS trials in Africa. The array was genotyped with the 50K Illumina SNP platform at the USDA-ARS lab at Fargo, ND.
Additional Outcomes (in reverse chronological order):
*Please send requests for data access, and any questions/suggestions to Chris Massman: firstname.lastname@example.org