|Mornhinweg, Dolores - Do|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2008
Publication Date: 7/1/2008
Citation: Mittal, S., Dahleen, L.S., Mornhinweg, D.W. 2008. Locations of genes conferring Russian wheat aphid resistance in barley germplasm STARS-9301B. Crop Science. 48:1452-1458 Interpretive Summary: Russian wheat aphids (RWA) feed on plants like barley and have caused more than $1 billion in losses in the Western United States since they were first identified in Texas in 1986. Russian wheat aphid infestations reduce grain yield and quality of barley and some producers have ceased to grow barley due to RWA damage. While insecticides can be used to control RWA, they are expensive and can leave chemical residues in barley products. We examined RWA resistance from the barley line STARS-9301B by crossing it to a susceptible line Morex to determine the locations of genes for resistance. Progeny from the cross were evaluated twice in the greenhouse for RWA resistance and were screened for differences in DNA markers. Results indicated that STARS-9301B contains two RWA resistance genes, one each on chromosomes 1H and 3H. A potential minor RWA resistance gene was located on chromosome 2H. DNA markers linked to the genes will be useful for incorporating multiple RWA resistance genes into barley cultivars.
Technical Abstract: Russian wheat aphid (RWA, Diuraphis noxia Mordvilko) infestations of barley reduce grain yield and quality and have caused more than $1 billion in losses in the Western United States since 1986. Our objective was to map genes conferring resistance to RWA feeding damage in the germplasm line STARS-9301B via PCR-based marker assays of 196 F2-derived F3 families from the cross ‘Morex’/STARS-9301B'. Seedling reactions to RWA infestations were used to phenotype each family. A total of 107 molecular markers were used to construct a linkage map and QTL analysis identified two major QTL for resistance. The QTL on the short arm of chromosome 1H was associated with marker KV-12 and explained 26% of the variation for RWA reaction. A QTL on chromosome 3H associated with EBmac0541 explained 38% of the variation. A potential minor QTL on chromosome 2H was associated with marker SCSSR07759 and explained 6% of the variation. A combined analysis indicated that the three marker-QTL associations explained 59% of the phenotypic variation for RWA resistance. These linked markers will be valuable in pyramiding genes for long-term protection against RWA in barley.