Two previously undescribed potato viruses from South America

Abstract

THE proneness of potatoes (Solanum spp.) to virus diseases is well known, and about 20 viruses are recorded in naturally infected potatoes in Europe and North America^1,2. Many of these viruses also occur in the Andean region of South America. For example, in Peru several well known viruses were detected³ in ‘basic seed’ stocks by inoculating sap to a range of indicator species and by serological tests. Some indicator plants in these tests, however, developed symptoms unlike those typical of previously described potato viruses. These symptoms were of two main types, necrotic local lesions and systemic necrosis in Chenopodium quinoa, and systemic necrosis and shoot distortion in Phaseolus vulgaris cv. Pinto or Sanilac. We describe here the characterisation of the virus isolates producing these effects. Two previously undescribed viruses were identified: we call them potato black ringspot virus (PBRV) and potato virus T (PVT).