Identification of RFLP markers for resistance to wheat spindle streak mosaic bymovirus (WSSMV) disease

Wheat spindle streak mosaic bymovirus (WSSMV) causes an economically import ant disease of winter wheat in Europe and North America. Artificial inocula tion with this virus to identify resistant wheat genotypes is difficult. Th is study was conducted to identify restriction fragment length polymorphism (RFLP) markers associated with resistance to this disease. A population, c onsisting of 104 F-5 recombinant inbred lines from a cross between hexaploi d Triticum aestivum cultivars 'Geneva' (resistant) and 'Augusta' (susceptib le), was evaluated for WSSMV symptoms under field conditions for four years . Two linked markers on the long arm of chromosome 2D, Xbcd1095 and Xcdo373 , were determined to be associated with WSSMV resistance by bulked segregan t analysis of the 10 most resistant and 10 most susceptible lines. Marker X cdo373 accounted for 79% and Xbcd1095 for 73% of the phenotypic variation. Our results suggest that resistance to WSSMV in this population is qualitat ive in nature and is controlled by few genes. These markers should be usefu l in the development of wheat cultivars resistant to WSSMV and perhaps also to wheat yellow mosaic bymovirus (WYMV).