GENETIC ENHANCEMENT FOR RESISTANCE TO BIOTIC AND ABIOTIC STRESSES IN HARD WINTER WHEAT
Location: Hard Winter Wheat Genetics Research Unit
Title: Association study of resistance to soil-borne wheat mosaic virus (SBWMV) in U.S. winter wheat
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 20, 2011
Publication Date: October 15, 2011
Citation: Zhang, D., Bai, G., Hunger, R., Bockus, W., Yu, J., Carver, B., Brown Guedira, G.L. 2011. Association study of resistance to soil-borne wheat mosaic virus (SBWMV) in U.S. winter wheat. Phytopathology. 101:1322-1329.
Interpretive Summary: Soil-borne wheat mosaic virus (SBWMV) disease can cause significant yield losses of winter wheat. To identify genes for resistance to the disease in U.S. winter wheat, a selected set of 205 elite U.S. winter wheat experimental lines and cultivars was evaluated for virus symptoms at Manhattan, KS and Stillwater, OK. About 67% of lines showed at least moderately resistant reactions to the disease at the two locations. Association analysis identified one major gene for SBWMV resistance on the long arm of chromosome 5D. We suggested that it is the gene previously reported for soil borne cereal mosaic virus resistance. In addition, a gene on the short arm of chromosome 4D was also associated with disease resistance. Markers linked to the two genes should be useful in marker-assisted selection in U.S. winter wheat.
Soil-borne wheat mosaic virus (SBWMV) is one of the most important winter wheat pathogens worldwide. To identify genes for resistance to the virus in U.S. winter wheat, association study was conducted using a selected panel of 205 elite experimental lines and cultivars from U.S. hard and soft winter wheat breeding programs. Virus symptoms were evaluated twice in virus-infected fields for the panel at Manhattan, KS in spring 2010 and 2011 and for a subpanel of 137 hard winter wheat accessions at Stillwater, OK in spring 2008. At the two locations, 69.8% and 79.5% of cultivars were resistant or moderately resistant to the disease, respectively. After 282 simple sequence repeat (SSR) markers covering all wheat chromosome arms were scanned for association in the panel, a marker Xgwm469 on the long arm of chromosome 5D (5DL) showed a significant association with the disease rating. Three alleles (Xgwm469-165bp, -167bp, and -169bp) were associated with resistance, and the null allele was associated with susceptibility. Correlations between the marker and the disease rating were highly significant (0.80 in Manhattan at P<0.0001 and 0.63 in Stillwater at P<0.0001). The alleles Xgwm469-165bp and Xgwm469-169bp were present mainly in the hard winter wheat group, whereas allele Xgwm469-167bp was predominant in the soft winter wheat. The 169bp allele can be traced back to the cultivar Newton, and the 165bp allele to Aegilops tauschii. In addition, a novel locus on the short arm of chromosome 4D (4DS) was also identified to associate with the disease rating. Marker Xgwm469-5DL is closely linked to SBWMV resistance and highly polymorphic across the winter wheat accessions sampled in the study and thus should be useful in marker-assisted selection in U.S. winter wheat.