METHOD: ELISA, Visual Examination, slot-blot hybridization CONDITIONS: In Vitro - 16h light at 22C with light intensity of 6Klux METHOD NARR: Solanum species were mechanically innoculated with PVXcp. Estimates of PVX multiplicaELISA and slot-blot hybridization. Graft inoculation tests were used to confirm cases of extreme resistance. Results are given as mg PVX/g concentrations (range: 0.8-40) and visual symptoms. Hybridization results confirmedNATION: To asses PVX levels, an internal calibration curve was constructed by sampling a range of 4-600ng of purified PVX per well in each ELISA plate. Relative PVX concentration levels in 5 genotypes graft-inoculated are expe PVX concentration level in the tested genotype and its susceptible partner.