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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Peanut and Small Grains Research Unit » Research » Publications at this Location » Publication #401735
Research Project: Genetic Mechanisms and Improvement of Insect Resistance in Wheat, Barley, and Sorghum

Location: Peanut and Small Grains Research Unit

Title: Identification of a novel Pm65 allele conferring a wide spectrum of resistance to powdery mildew in wheat accession PI 351817

Author
item Xu, Xiangyang
item Li, Genqiao
item COWER, CHRISTINA - U.S. DEPARTMENT OF AGRICULTURE (USDA)
item BAI, GUIHUA - U.S. DEPARTMENT OF AGRICULTURE (USDA)
item CARVER, BRETT - OKLAHOMA STATE UNIVERSITY
item BIAN, RUOLIN - KANSAS STATE UNIVERSITY
item BERNARDO, AMY - U.S. DEPARTMENT OF AGRICULTURE (USDA)

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2023
Publication Date: 5/9/2023
Citation: Xu, X., Li, G., Cower, C., Bai, G., Carver, B.F., Bian, R., Bernardo, A. 2023. Identification of a novel Pm65 allele conferring a wide spectrum of resistance to powdery mildew in wheat accession PI 351817. Phytopathology. https://doi.org/10.1094/PHYTO-01-23-0032-R.
DOI: https://doi.org/10.1094/PHYTO-01-23-0032-R

Interpretive Summary: Powdery mildew is caused by the most adaptive biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), which inflicts wheat worldwide. Novel powdery mildew resistance genes that can be rapidly used in wheat cultivar development are urgently needed. PI 351817 is a German cultivar exhibiting a wide spectrum of resistance to Bgt isolates collected from different wheat-growing regions of the United States. In this study, a single, dominant powdery mildew resistance gene, designated Pm351817, was identified in the terminal region of chromosome arm 2AL in PI 351817. A set of 18 user-friendly, high throughput Kompetitive Allele specific PCR (KASP) markers were developed, and Pm351817 was delimited to a 634 kb interval between KASP markers Stars-KASP656 and Stars-KASP662. Pm351817, a novel allele at the Pm65 locus, conferred resistance to all Bgt isolates tested in this study and therefore can be used to enhance powdery mildew resistance in the United States. KASP markers flanking Pm351817 can be used to select Pm351817 in wheat breeding programs.

Technical Abstract: Powdery mildew is caused by the most adaptive biotrophic fungus Blumeria graminis f. sp. tritici (Bgt) inflicting wheat worldwide, and novel powdery mildew resistance genes that can be rapidly used in wheat cultivar development are urgently needed. PI 351817 is a German cultivar exhibiting a wide spectrum of resistance to Bgt isolates collected from different wheat-growing regions of the United States. Evaluation of an F2 population and 237 F2:3 lines derived from OK105960-2C14 × PI 351817 for responses to Bgt isolate OKS(14)-B-3-1 identified a single, dominant gene, designated Pm351817, for powdery mildew resistance in PI 351817. Using bulked segregant analysis (BSA) and simple sequence repeat (SSR) markers, Pm351817 was mapped in the terminal region of the long arm of chromosome 2A. Deep sequencing of the genotyping-by-sequencing libraries of the two parental lines identified a set of single nucleotide polymorphism (SNPs) markers in the 2AL candidate gene region, and those SNP markers was subsequently converted to Kompetitive Allele specific PCR (KASP) markers for genotyping the mapping population. Linkage analysis delimited Pm351817 to a 634 kb interval between Stars-KASP656 (771,207,512 bp) and Stars-KASP662 (771,841,609 bp) on 2AL based on the Chinese Spring reference sequence IWGSC RefSeq v2.0. Tests of allelism indicated that Pm351817 is located at the Pm65 locus. Pm351817 shows resistance to all Bgt isolates used in this study and can be used to enhance powdery mildew resistance in the United States, and KASP markers flanking Pm351817 can be used to select Pm351817 in wheat breeding programs after further tests for polymorphism.