1Division of Plant Pathology, Central Potato Research Institute, Simla-171001 (H. P.)
Through graft transmission studies, Nicotiana excelsior, N. megalosiphon, N. sylvestris, N. tabacum cvs. NC 95 & Samsun NN were recorded additional hosts of purple top roll and N. excelsior, N. megalosiphon, N. sylvestris, N. tabacum var Ambalema, Burley 21, Delcrest, Kanak Prabha, McNair 12, Samsun, Samsun NN, Xanthi nc were found to be additional hosts of marginal flavescence. They are important in maintaining the pathogen cultures during potato-off-season; also as differentials and filter plants for these pathogens. N. stolonifolia was found to be immune to both the pathogens.