Diagnostic markers for Soil-borne wheat mosaic virus resistance in soft red winter wheat

1. Diagnostic markers for Soil-borne wheat mosaic virus resistance in soft red winter wheat Yuanfeng Hao1, Yingying Wang1, Zhenbang Chen1, Dan Bland1, Gina Brown-Guedira2, Jerry Johnson1* 1 Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, GA 30223, USA 2 USDA-ARS Plant Science Research, Department of Crop Science, North Carolina State University, Raleigh, NC 27695, USA * Corresponding author: jjohnso@uga.edu Soil-borne wheat mosaic virus 2010 GAWN* Abstract We recently showed that two co-dominant SSR markers Xbarc161 and Xbarc177 were closely linked with the major QTL for SBWMV resistance in Pioneer 26R61 and AGS 2020. The two markers were suitable for marker-assisted selection in Pioneer 26R61 background. The aim of this study was to validate the marker effectiveness in genetically diverse backgrounds. Seventy-five advanced lines in 2010 Gulf Atlantic Wheat Nursery (GAWN), and 38 tested lines in 2011 Uniform Eastern Soft Red Winter Wheat Nursery (UESRWWN) were used. These lines were mainly contributed by the public breeding units from 15 States in USA, covering nearly all winter wheat growing regions, and other few lines were provided by private company including Limagrain, Syngenta/AgriPro, Trio Research Inc. and Pioneer Hi-Bred. Pioneer 26R61 and AGS 2000 were used as positive and negative checks for marker detection, respectively. For the 2010 GAWN material, the phenotype data was collected in Plains, GA, and genotype was conducted in Small Grains Lab in University of Georgia. Out of 75 lines, 73 showed the consistency between the phenotype and the genotype, and two other lines were negative for linked markers but resistant to SBWMV in the field. Therefore, new gene (s) might be present in the two lines. And for the 2011 UESRWWN material, the genotype data for the 38 lines totally agreed with the phenotype data in Clarksville, MD. The genotype work was conducted by USDA-Eastern Regional Small Grains Genotyping Lab in North Carolina State University. These results demonstrate that Xbarc161 and Xbarc177 are highly diagnostic for detection of SBWMV resistance in diverse genetic material, and also can be used as a starting point for discovering new resistant genes for SBWMV in wheat. • Soil-borne wheat mosaic virus (SBWMV) is an important viral disease in US, and can practically destroy the entire crop of a susceptible cultivar. • SBWMV belongs to genus Furovirus, vectored by the plasmodiophoridPolymyxagraminis, can survive in soil for decades until a suitable host plant is encountered. • Utilization of resistant varieties is currently the only practical and environmentally friendly means for controlling SBWMV. • Development of resistant cultivars is restrained by germplasm screening in the field, however, quick and accurate laboratory-based marker-assisted selection can facilitate the selection procedure. • Two co-dominant SSR markers Xbarc161 and Xbarc177, closely linked with SBWMV resistance at Sbm1 locus on chromosome 5DL, were previously identified (Hao et al. 2011 TAG, submission). Linked markers of QSbm.uga-5DL * GAWN: Gulf Atlantic Wheat Nursery 2011 UESRWWN* Acknowledgement QSbm.uga-5DLwas detected across all environments based on the linkage maps of chromosome 5D in the Pioneer 26R61/AGS 2000 population (a) and the AGS 2020/LA 95135 population (b). The QTL region is indicated as a red rectangle The authors acknowledge the financial support by the National Research Initiative of USDA’s Cooperative State Research, Education and Extension Service, CAP (Grant No. 2006-55606-16629). Contact Yuanfeng Hao UGA, Griffin Campus 1109 Experiment St., Griffin 30223 Email: yfhao@uga.edu * UESRWWN: Uniform Eastern Soft Red Winter Wheat Nursery The distribution of the tested lines in GAWN & UESRWWN in 15 States of the USA, the number means the amount of lines The typical amplification of marker Xbarc177 in GAWN entry G1-G38, P26R61 is positive check, and AGS 2000 is negative