VIEW ARTICLE

Spread of Seed-Borne Barley Stripe Mosaic Virus and Effects of the Virus on Barley in California. S. A. Slack, Department of Plant Pathology , University of California, Davis 95616, Current address of senior author: Department of Plant Pathology, University of Wisconsin, Madison 53706; R. J. Shepherd(2), and D. H. Hall(3). (2)(3)Department of Plant Pathology , University of California, Davis 95616. Phytopathology 65:1218-1223. Accepted for publication 23 May 1975. DOI: 10.1094/Phyto-65-1218.

Barley was planted at two locations in California which corresponded to two different growing seasons, to determine the spread of barley stripe mosaic virus (BSMV) and its effect on yield. Greater spread of the virus and higher percentage of seed transmission occurred in spring-seeded barley than when the same cultivars were sown in the fall. Spread was effected by leaf contact transmission, but not by infected pollen dispersal. The possibility that BSMV can be reduced or eliminated from spring-seeded barley by producing seed sources in fall-seeded areas is suggested. BSMV infection of barley cultivar CM67 resulted in the production of significantly fewer and smaller seed. BSMV was found to have a detrimental effect both on male and female gametes of CM67 barley. Fertilized ovules from infected plants of this cultivar set approximately 10% less seed than ovules from healthy plants. Plants of infected cultivars CM67 and Firlbecks III produced less pollen per anther and a smaller percentage of apparently mature pollen grains (as determined by iodine stainability) than comparable healthy plants. Early infection of CM67 barley with BSMV resulted in reduced seed set and germinability and 38-45% seed transmission; in contrast, inoculation at heading produced no detectable effects compared to uninoculated controls.