Effect of combining two genes for partial resistance to Barley yellow dwarf virus-PAV (BYDV-PAV) derived from Thinopyrum intermedium in wheat

Abstract : In this study two Sources of resistance to Barley yellow dwarf virus (BYDV), both originating from Thinopyrum intermedium, were combined in a single genotype, line ZT, using GISH (genomic in situ hybridization) and a new molecular marker of the partial resistance gene Bdv2. Susceptible wheat cv. Sunstar, the translocation line TC14 carrying Bdv2, the addition line ZH with the group-2 chromosome arm carrying resistance, and line ZT with both resistances were inoculated with five strains of Barley yellow dwarf virus-PAV. The tests confirmed the resistance of TC14 and ZH and revealed an additive effect of the two sources of resistance in ZT. The resistance of line ZT was characterized by 1 proportion of infected plants significantly lower than the parental lines TC14 and ZH (42% vs. a mean of 76% for the parents) and a very low virus titre (area under the virus concentration progress curve of 1.2 vs. a mean on 6.3 for the parents).