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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Cereal Crops Research » Research » Publications at this Location » Publication #397050

Research Project: Improvement of Biotic Stress Resistance in Durum and Hard Red Spring Wheat Using Genetics and Genomics

Location: Cereal Crops Research

Title: High resolution melting (HRM) based marker development for wheat leaf rust resistance gene Lr34

Author
item KAUR, SHIVREET - North Dakota State University
item PENNINGTON, TAYLOR - North Dakota State University
item CONLEY, EMILY - University Of Minnesota
item GREEN, ANDREW - North Dakota State University
item Kolmer, James - Jim
item ANDERSON, JAMES - University Of Minnesota
item Gupta, Rajeev
item GILL, UPINDER - North Dakota State University

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2022
Publication Date: 11/8/2022
Citation: Kaur, S., Pennington, T., Conley, E., Green, A., Kolmer, J.A., Anderson, J., Gupta, R., Gill, U. 2022. High resolution melting (HRM) based marker development for wheat leaf rust resistance gene Lr34. Phytopathology. https://doi.org/10.1094/PHYTO-08-22-0313-R.
DOI: https://doi.org/10.1094/PHYTO-08-22-0313-R

Interpretive Summary: Global wheat production is continuously constrained by emergence of new and more virulent races of pathogens causing several economically important diseases. Among these, fungal pathogens are known to cause several important foliar diseases in wheat including three rusts: leaf rust, stem rust and stripe rust. Leaf rust alone is responsible for 3.25% yield loss in global wheat production annually. Deploying adult plant resistance (APR) against rust diseases is an important breeding objective of most wheat breeding programs. The gene Lr34 is the most effective and successfully deployed APR gene in wheat against leaf rust fungus. Various molecular markers have been developed for Lr34 but, either they require post-PCR handling processes or are not economical. Herein, we developed a high-resolution-melting (HRM) based diagnostic assay for Lr34 which was able to differentiate a set of resistant and susceptible breeding lines accurately. To our knowledge, this is the first report of an HRM assay for genotyping a wheat rust resistance gene and could be deployed in wheat breeding programs.

Technical Abstract: Deploying adult plant resistance (APR) against rust diseases is an important breeding objective of most wheat breeding programs. The gene Lr34 is the most effective and successfully deployed APR gene in wheat against leaf rust fungus Puccinia triticina. Various molecular markers have been developed for Lr34 but, either they require post-PCR handling processes or are not economical. Herein, we developed an HRM based diagnostic assay for Lr34 based on a three bp ‘TTC’ deletion in exon 11 of the resistant allele. The susceptible cv. Thatcher and its near-isogenic Thatcher Lr34 (RL6058) with Lr34, yielded distinct melting profiles and were differentiated with high reproducibility. For further validation, all three copies of Lr34 were cloned in plasmid vectors and HRM analysis using individual and combination (equimolar mixture of three copies) of homoeologs yielded distinguishing melting profiles. When compared with a KASP Lr34 assay, the HRM assay was able to differentiate a set of resistant and susceptible breeding lines more accurately. To our knowledge, this is the first report of an HRM assay for genotyping a wheat rust resistance gene.