Turnip yellows virus (TuYV) is a damaging pathogen severely reducing yields of oilseed rape (OSR) (3rd most widely grown crop in UK). UK losses are estimated at >15%, costing £69 million/annum. It also significantly reduces the yield (up to 65%) and quality of brassica vegetables (e.g. cabbage and sprouts). In earlier BBSRC-funded research, we identified sources of natural plant resistance to TuYV that were effective against the different strains of TuYV. The aim of the proposed research is to work together with commercial plant breeders from different companies to provide plant lines with our resistances to TuYV and tools (molecular markers) needed for our commercial partners to move the resistances in to commercial OSR and vegetable brassica crop varieties. The breeding of the virus-resistant varieties will increase yields, thereby helping food security and also reduce the amounts of pesticides farmers spray on crops, in attempts to stop the greenfly vectors spreading TuYV