Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/12/1998
Publication Date: N/A
Technical Abstract: The barley varieties 'Morex' and 'Modjo-1' are susceptible to barley stripe mosaic virus (BSMV) strain ND18, but are resistant to strain CV42. Although both 'Morex' and 'Modjo-1' are believed to possess the recessive BSMV resistance gene rsm 1, 'Modjo-1' exhibits a higher level of resistance. Using recombinant viruses generated from ND18 and CV42, we have mapped the determinants of BSMV pathogenicity to these hosts. Although we previously showed that pathogenicity to oat could be conferred to ND18 by as little as a single nucleotide change in the sequence of RNA alpha (C-2261 to A-2261), the sequence responsible for pathogenicity to barley was not determined. Pathogenicity determinants for 'Morex' barley have now been found to be in the same region previously identified as critical to oat pathogenicity. Additional sequence changes are required for pathogenicity to 'Modjo-1' barley. The possible significance of the additional sequence requirements for 'Modjo-1' pathogenicity will be discussed.