Barley yellow dwarf virus-PAV, among the virus species that cause yellow dwarf disease in winter cereals, is predominant in Southern Brazil. Genetic resistance and tolerance to the virus and to the aphid vector are important strategies to control this virus. BRS Timbaúva shows low reduction of productivity, in relation to other wheat cultivars, when exposed to aphid-virus complex, and is resistant to the Rhopalosiphum padi vector. This work aimed to establish if this cultivar is also resistant or tolerant to BYDV-PAV. The experiments were carried out comparing BRS Timbaúva and Embrapa 16 (susceptible and intolerant). Virus resistance was evaluated by viral growth curves and tolerance estimated by morphological and yield components in relation to healthy plants. Inoculum pressure effects on resistance/tolerance were also evaluated. BRS Timbaúva was as susceptible to viral infection as Embrapa 16, but in all experiments its productivity loss was lower than that of Embrapa 16, which suggests its BYDV-PAV tolerance. BRS Timbaúva field behavior may be associated with vector resistance and virus tolerance.
Luteovirus; B/CYDV; aphids
