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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Publications at this Location » Publication #393076
Research Project: Cereal Rust: Pathogen Biology and Host Resistance

Location: Cereal Disease Lab

Title: Origin and genetic analysis of stem rust resistance in wheat line Tr129

Author
item SHARMA, JYOTI - Agriculture And Agri-Food Canada
item FETCH, THOMAS - Agriculture And Agri-Food Canada
item GHAZVINI, HABIBOLLAH - Agricultural Research, Education And Extension Organization (AREEO)
item Rouse, Matthew
item DANILOVA, TATIANA - North Dakota State University
item FRIEBE, BERND - Kansas State University
item HIEBERT, COLIN - Agriculture And Agri-Food Canada

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2022
Publication Date: 3/17/2022
Citation: Sharma, J.S., Fetch, T.G., Ghazvini, H., Rouse, M.N., Danilova, T., Friebe, B., Hiebert, C.W. 2022. Origin and genetic analysis of stem rust resistance in wheat line Tr129. Scientific Reports. 12. Article 4585. https://doi.org/10.1038/s41598-022-08681-4.
DOI: https://doi.org/10.1038/s41598-022-08681-4

Interpretive Summary: Wheat is harvested from over 37 million acres in the United States. The rust diseases of wheat can cause devastating yield losses. In order to mitigate stem rust of wheat, varieties with genetic resistance are needed. The objective of this study was to characterize the genetics of stem rust resistance in wheat line Tr129. Mapping and phenotyping showed that Tr129 carried four stem rust resistance (Sr) genes on chromosome arms 2BL (Sr9b), 4AL (Sr7b), 6AS (Sr8a), and 6DS (SrTr129). SrTr129 co-segregated with markers for SrCad, however Tr129 has a unique haplotype suggesting the resistance could be new. We also found that like SrTr129, SrCad is ineffective against three North American stem rust pathogen races, but resistant to emerging strains of the stem rust pathogen such as Ug99. Tr129 and the DNA markers reported here are useful resources for developing new stem rust resistant varieties of wheat for the United States.

Technical Abstract: Wheat line Tr129 is resistant to stem rust, caused by Puccinia graminis f. sp. tritici (Pgt). The resistance in Tr129 was reportedly derived from Aegilops triuncialis, but the origin and genetics of resistance have not been confirmed. Here, genomic in situ hybridization (GISH) showed that no Ae. triuncialis chromatin was present in Tr129. Genetic and phenotypic analysis was conducted on F2 and DH populations from the cross RL6071/Tr129. Seedlings were tested with six Pgt races and were genotyped using an Illumina iSelect 90 K SNP array and kompetitive allele specific PCR (KASP) markers. Mapping and phenotyping showed that Tr129 carried four stem rust resistance (Sr) genes on chromosome arms 2BL (Sr9b), 4AL (Sr7b), 6AS (Sr8a), and 6DS (SrTr129). SrTr129 co-segregated with markers for SrCad, however Tr129 has a unique haplotype suggesting the resistance could be new. Analysis of a RL6071/Peace population revealed that like SrTr129, SrCad is ineffective against three North American races. This new understanding of SrCad will guide its use in breeding. Tr129 and the DNA markers reported here are useful resources for improving stem rust resistance in cultivars.