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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 #415668
Research Project: Genetic Improvement for Resistance to Aphids and Major Diseases in Wheat, Barley, and Sorghum in the Great Plains

Location: Peanut and Small Grains Research Unit

Title: Characterization of a gene conferring resistance to U.S. Russian wheat aphid biotypes in the Iranian wheat landrace PI 625139

Author
item Xu, Xiangyang
item Li, Genqiao
item WATIRA, TEZERA WOLABU - Oklahoma State University
item Bai, Guihua
item BIAN, RUOLIN - Kansas State University
item Bernardo, Amy
item CARVER, BRETT - Oklahoma State University
item WU, YANQI - Oklahoma State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Russian wheat aphid (RWA, Diuraphis noxia Kurdjumov) is a highly invasive and destructive wheat pest. RWA resistant wheat cultivars are preferred for managing RWA because RWA can avoid insecticides by living on the inside of rolled wheat leaves. However, RWA evolves rapidly to overcome wheat resistance and most RWA resistance genes have lost effectiveness to new RWA biotypes. Therefore, novel RWA resistance genes are needed to sustain wheat production. The Iranian landrace PI 625139 is resistant to all U.S. RWA biotypes and is valuable for developing RWA resistant wheat cultivars. A genetic analysis was conducted, leading to the discovery of a new RWA resistance gene, designated Dn625139, in the short arm of chromosome 7D. Dn625139 confers resistance to all U.S. RWA biotypes and can be widely used in U.S. wheat breeding programs. Molecular markers that closely linked to Dn625139 were subsequently developed. These markers can be used to trace Dn625139 in breeding populations and rapidly transfer Dn625139 into new cultivars.

Technical Abstract: Russian wheat aphid (RWA, Diuraphis noxia Kurdjumov) is a highly invasive and destructive wheat pest evolving rapidly to overcome host resistance. Novel genes conferring resistance to multiple RWA biotypes are needed to sustain wheat production. The Iranian landrace PI 625139 was previously identified to be resistant to all five U.S. RWA biotypes. To map the RWA resistance gene in PI 625139, both F2 and F2:3 populations were developed from cross PI 625139 × OK11D25060, and the F2:3 population was evaluated for responses to infestation by five US RWA biotypes, RWA1, RWA2, RWA3/7, RWA6, and RWA8. RWA assays identified a single gene in PI 625139, designated Dn625139, conditioning resistance to all the five U.S. RWA biotypes. Selective genotyping of a subset of F2 plants using genotyping-by-sequencing (GBS) revealed a set of single nucleotide polymorphism (SNP) markers in a chromosome region on the short arm of chromosome 7D that closely associated with RWA resistance. Kompetitive allele specific PCR (KASP) markers were developed for selected GBS-SNPs in the 7DS region. Genetic analysis using the new KASP and simple sequence repeat (SSR) markers placed Dn625139 to a 2.6 cM interval. Dn625139 was 1.2 cM proximal to the KASP marker Stars-KASP1007 (169.57 Mb) and 1.4 cM distal to the SSR marker Stars1039 (195.27 Mb) in the Chinese Spring IWGSC RefSeq v2.1 reference sequence, and co-segregated with the SSR marker Stars1029 (180.82 Mb) in chromosome arm 7DS. Dn625139 is a valuable gene resistant to multiple RWA biotypes and the molecular markers developed in this study will facilitate its rapid introgression into locally adapted cultivars to enhance wheat RWA resistance.