VIEW ARTICLE

Properties of Tobacco Necrosis Virus Strains Isolated From Apple. J. K. Uyemoto, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva, New York 14456; R. M. Gilmer, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva, New York 14456. Phytopathology 62:478-481. Accepted for publication 1 November 1971. DOI: 10.1094/Phyto-62-478.

Tobacco necrosis virus (TNV) was sporadically isolated from certain crude apple sap inocula that only occasionally incited 1-2 lesions/Chenopodium quinoa indicator. When these inocula were concentrated and partially purified by differential centrifugation, infectivity was often greatly increased, and isolation of TNV was more consistent. TNV was isolated from apple leaves and fruits with this technique. Several TNV isolates from apple induced a mixture of white and necrotic lesions in cowpea. Each lesion type was unstable; selections of either induced white lesions at 28 C and necrotic lesions at 15 C. These isolates were alike antigenically, and the one isolate tested selectively activated satellite virus B. Another TNV isolate from apple induced only necrotic lesions in cowpea irrespective of temperature. It differed antigenically from mixed-lesions isolates and selectively activated satellite virus C.