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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Publications at this Location » Publication #357153

Research Project: Cereal Rust: Pathogen Biology and Host Resistance

Location: Cereal Disease Lab

Title: A backcross line of Thatcher wheat with adult plant leaf rust resistance derived from Duster wheat has Lr46 and Lr77

item Kolmer, James - Jim
item SU, ZHI - Kansas State University
item BERNARDO, AMY - Kansas State University
item Bai, Guihua
item Chao, Shiaoman

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2018
Publication Date: 8/1/2018
Citation: Kolmer, J.A., Su, Z., Bernardo, A., Bai, G., Chao, S. 2018. A backcross line of Thatcher wheat with adult plant leaf rust resistance derived from Duster wheat has Lr46 and Lr77. Phytopathology.

Interpretive Summary: Wheat is attacked by the leaf rust fungus, Puccinia triticina. Genes in wheat can provide resistance to this important pathogen and disease of wheat. The wheat cultivar Duster which was developed in the United States, has had long lasting resistance to leaf rust. The objective of this research was to determine on what chromosomes the long lasting leaf rust resistance genes in Duster are found. Duster had a major gene for leaf rust resistance on chromosome 3BL, and another gene on chromosome 1BL. The resistance gene on 3BL was a new gene and was designated as Lr77, the gene on 1BL was Lr46. Duster can be used as a parent by wheat breeders and plant pathologists to improve the leaf rust resistance in wheat improvement programs.

Technical Abstract: The widely grown hard red winter wheat cultivar Duster released in 2006 has remained highly resistant to leaf rust, caused by Puccinia triticina in the southern Great Plains of the United States. In contrast, many of the winter wheat cultivars in this region are susceptible to leaf rust. The goal of this study was to identify the number and chromosome location of leaf rust resistance genes in a line of Thatcher*2/Duster wheat that was selected for adult plant leaf rust resistance. The Thatcher*2/Duster line was crossed with Thatcher (Tc) and a recombinant line inbred line (RIL) population was advanced to F6 generation by single seed descent. The parents and RIL population were phenotyped for leaf rust resistance in three field plot tests and in an adult plant greenhouse test. Single nucleotide polymorphism (SNP) markers derived from the Illumina Infinium iSelect 90K wheat SNP array, kompetitive allele specific polymerase chain reaction (KASP) assays on chromosome 3BL, and a sequence tagged site (STS) marker on chromosome 1BL were used to construct a genetic map of the RIL population. The STS marker csLV46G22 that is linked with resistance gene Lr46 on chromosome 1BL, and SNP marker IWB10344 that is linked with Lr77 on chromosome 3BL, were significantly associated with lower leaf rust severity. Duster has at least three adult plant resistance genes for leaf rust resistance since it was previously determined to also have the adult plant resistance gene Lr34. Duster is a valuable source of durable leaf rust resistance for hard red winter wheat improvement in the Great Plains region.