VIEW ARTICLE

An Ultrasonic Inoculation Method for Tobacco Mosaic Virus Bioassay. Calvin R. Lamborn, Associate Director of Research, Gallatin Valley Seed Co., Twin Falls, Idaho 83301; George W. Cochran(2), and John L. Chidester(3). (2)(3)Professor and Research Associate, respectively, Department of Botany, Utah State University, Logan, Utah 84321. Phytopathology 61:1015-1019. Accepted for publication 23 March 1971. DOI: 10.1094/Phyto-61-1015.

An ultrasonic inoculation method for a sensitive bioassay of tobacco mosaic virus on halves of detached primary leaves of bean is described. The pressure of the leaf against the apparatus, the speed of an inoculation passage, and the power level of the ultrasonic energy all influenced the sensitivity of the bioassay. One thousand-mesh Carborundum proved to be the best abrasive for the method. When the volume of inoculum used per half-leaf was as small as 1 µliter, the inoculation efficiency was greatest. This inoculation method consistently gave straight line curves through 1,000-fold dilutions, and increased the sensitivity of the bioassay above finger-rubbing 88-fold. The ultrasonic method was quick, easy, and reproducible from operator to operator and from day to day.