Mechanical Transmission, Partial Purification, and Preliminary Chemical Analysis of Barley Yellow Streak Mosaic Virus. Nancy L. Robertson, Former Graduate Student and Postdoctoral Research Associate, Department of Plant Pathology, Montana State University, Bozeman 59717. Thomas W. Carroll, Professor, Department of Plant Pathology, Montana State University, Bozeman 59717. Plant Dis. 75:839-843. Accepted for publication 18 February 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0839.

Barley yellow streak mosaic virus (BaYSMV), shown previously to be transmitted to barley only by the brown wheat mite, Petrobia latens, was transmitted to Nicotiana benthamiana and Chenopodium quinoa by mechanical inoculation with sap from diseased barley leaves. Transmission of BaYSMV also occurred when leaf sap from diseased N. benthamiana was used to mechanically inoculate healthy N. benthamiana. No transmission occurred, however, when barley was mechanically inoculated with leaf sap from diseased N. benthamiana. BaYSMV was partially purified by centrifugation. Two prominent bands formed in sucrose step gradients at the 30/40 and 40/60% interfaces. Electron microscopy revealed that most virus particles were present in the 40/60% interface band. N. benthamiana mechanically inoculated with either band became infected. Preliminary chemical analysis of BaYSMV-enriched preparations showed that they contained unique high molecular weight RNAs (11–13 kb) and proteins of 32 and 100 kDa.