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ARS Home » Plains Area » Stillwater, Oklahoma » Wheat, Peanut, and Other Field Crops Research » Research » Publications at this Location » Publication #361927

Research Project: Genetic Mechanisms and Improvement of Insect Resistance in Wheat, Barley, and Sorghum

Location: Wheat, Peanut, and Other Field Crops Research

Title: Characterization of Pm65, a new powdery mildew resistance gene on chromosome 2AL of a facultative wheat cultivar

Author
item LI, GENQIAO - Oklahoma State University
item Cowger, Christina
item WANG, XUEWEN - University Of Georgia
item CARVER, BRETT - Oklahoma State University
item Xu, Xiangyang

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2019
Publication Date: 6/18/2019
Citation: Li, G., Cowger, C., Wang, X., Carver, B.F., Xu, X. 2019. Characterization of Pm65, a new powdery mildew resistance gene on chromosome 2AL of a facultative wheat cultivar. Theoretical and Applied Genetics. 132(9):2625-2632. https://doi.org/10.1007/s00122-019-03377-2.
DOI: https://doi.org/10.1007/s00122-019-03377-2

Interpretive Summary: Wheat powdery mildew, a widely occurring disease caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), poses a serious threat to wheat production. A high breeding priority is to identify powdery mildew resistance genes that can be readily used either alone or in gene complexes involving other disease resistance genes. A new powdery mildew resistance gene, designated Pm65, was identified in wheat cultivar Xinmai 208. Linkage analysis delimited Pm65 to a 0.5 cM interval on the long arm of chromosome 2A in the Chinese Spring reference sequence., and an allelism test indicated that Pm65 is a new gene about 10.3 cM distal to the Pm4 locus. Pm65 was 0.3 cM proximal to Xstars355 and 0.2 cM distal to Xstars356. It conferred near-immunity to 19 of 20 Bgt isolates collected from different wheat-growing regions of the USA. Coming from a high-yield potential cultivar, Pm65 can be directly used to enhance powdery mildew resistance in wheat. The newly developed SSR markers Xstars355 and Xstars356 have the potential to tag Pm65 for wheat improvement.

Technical Abstract: Wheat powdery mildew, a widely occurring disease caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), poses a serious threat to wheat production. A high breeding priority is to identify powdery mildew resistance genes that can be readily used either alone or in gene complexes involving other disease resistance genes. An F2 population and 227 F2:3 families derived from the cross Xinmai 208 × Stardust were generated to map a powdery mildew resistance gene in Xinmai 208, a high-yielding Chinese wheat cultivar. Genetic analysis indicated that Xinmai 208 carries a single dominant powdery mildew resistance gene, designated herein Pm65, and linkage analysis delimited Pm65 to a 0.5 cM interval covering 531.8 Kb (763,289,667 – 763,821,463 bp) on chromosome 2AL in the Chinese Spring reference sequence. An allelism test indicated that Pm65 is a new gene about 10.3 cM distal to the Pm4 locus. Pm65 was 0.3 cM proximal to Xstars355 and 0.2 cM distal to Xstars356. It conferred near-immunity to 19 of 20 Bgt isolates collected from different wheat-growing regions of the USA. Coming from a high-yield potential cultivar, Pm65 can be directly used to enhance powdery mildew resistance in wheat. The newly developed SSR markers Xstars355 and Xstars356 have the potential to tag Pm65 for wheat improvement.