Potato Viruses of Economic Importance for Production of Planting Material in Bulgaria

Potato is the world's third most widespread food crop, following wheat and rice. Tubers play an im¬portant role in the spread of virus diseases in different regions in Bulgaria for seed production. The most important viruses in potatoes in Bulgaria include Potato virus Y (PVY), Potato leaf roll virus (PLRV), Potato virus S (PVS), and Potato virus M (PVM). Most of the viruses in potatoes do not induce symptoms in tubers, which plays an important role in viral dissemination by the growers. In this way, after planting the tubers, the quality and yield of the production may be severely reduced. The use of virus-free tubers by growers is of key importance for the control of diseases and the reduction of loss of production.