VIEW ARTICLE

A Severe Strain of Tobacco Mosaic Virus from Cactus. Lallan Giri, Department of Botany, University of Montana, Missoula 59801; M. Chessin, Department of Botany, University of Montana, Missoula 59801. Phytopathology 65:824-825. DOI: 10.1094/Phyto-65-824.

A previously unreported strain of tobacco mosaic virus was found in the Beavertail cactus, Opuntia basilaris, growing in the wild. Host reactions were most like those induced by the yellow-mottling distorting-type and J14D1 strains in Nicotiana sylvestris and Turkish tobacco, respectively. In crude sap, the thermal inactivation temperature was 85-90 C, and the dilution end point 10^–8 – 10^–9. Long needles were observed in polyethylene glycol precipitates of infected sap. Electron microscopy of purified virus revealed rigid rods typical of TMV with an NML of 302±5 nm. A sedimentation coefficient of 183S was determined. The virus was serologically related to common TMV.