DISTRIBUTION OF TOBACCO-STREAK, TOMATO-RINGSPOT, AND RASPBERRY-BUSHY-DWARF VIRUSES IN RUBUS-URSINUS AND R-LEUCODERMIS COLLECTED FROM THE PACIFIC-NORTHWEST

Clonal and seed propagules of Rubus ursinus, the trailing blackberry, and seed of R. leucodermis, the western black raspberry, were collecte d from throughout the Pacific Northwest (Oregon, Washington, and Briti sh Columbia). The collections were made in four general environmental regions: at sea level along the Pacific coast, in the coastal mountain s adjacent to the coast, in the Willamette Valley, and in the Cascade Mountains. After the resulting propagules were established, leaves wer e tested by enzyme-linked immunosorbent assay according to standard pr ocedures. None of the R. leucodermis samples tested positive for raspb erry bushy dwarf idaeovirus (RBDV), tomato ringspot nepovirus (TomRV), or tobacco streak ilarvirus (TSV). Rubus leucodermis is either resist ant to these viruses or their vectors, the viruses are not seed transm itted in this species, or the viruses were not detected due to inadequ ate sampling. No samples of R. ursinus tested positive for RBDV or Tom RV. Samples from 77% of the sites where cuttings were taken and 37% of the seedling populations tested positive for TSV. Along the Pacific c oast, only 20% of the sites sampled by cuttings tested positive for TS V. However, the percentage of infected sites where cuttings were taken increased to 88 and 100% in the coastal mountains and the Cascade Mou ntains, respectively. Along the Pacific coast, 14% of seedling sites t ested positive for TSV The number of TSV positive seedling sites incre ased to 45 and 36% in the Cascade Mountains and the coastal mountains, respectively. The Willamette Valley site tested negative for TSV. Wit h one exception, all of the low elevation sites tested negative for TS V Prevailing winds or earlier flowering may prevent some of these Paci fic Coast populations from becoming infected. Many of the TSV positive sites had some samples that tested negative, indicating that TSV is u nevenly distributed within these populations.