VIEW ARTICLE

Disease Control and Pest Management

Uneven Distribution of Tobacco Streak Virus in Santiam Blackberry Before and After Heat Therapy. Richard H. Converse, Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331; Phytopathology 68:241-244. Accepted for publication 1 August 1977. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-241.

Santiam is an Oregon blackberry cultivar that is naturally infected with the Rubus strain of tobacco streak virus (TSV-R). Indexing of softwood propagants showed that TSV-R was unevenly distributed in the shoot system when Santiam plants were grown at normal greenhouse temperatures. When grown at a constant 37 C over a 14-mo period, Santiam plants also produced both healthy and virus-infected propagants. The percentage of infected propagants varied with the source of the mother plant, increased in cyclic fashion with time, but was not influenced by the nodal position on the shoot from which the propagant was taken. Santiam-75, a clone obtained free from known viruses, produced significantly (32%) more shoots in field tests than stock infected with TSV-R.