Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: April 25, 2005
Publication Date: June 1, 2005
Citation: Lee, L., Hunter, W., Dawson, W., Hilf, M. 2005. Variability in transmission of Citrus tristeza virus isolates from Florida by Toxoptera Citricida. Phytopathology. 95:S58. Technical Abstract: Fifteen florida isolates of Citrus tristeza virus (CTV) were tested for transmissibility by the brown citrus aphid (Toxoptera citricida Kirkaldy) (BrCA). A CTV isolate with the T68 genotype, propagated by successive graft inoculation for 25 years was readily transmitted by BrCA, with 45-80% of receptor plants infected. A CTV isolate with the T36 genotype, propagated by successive graft inoculation for 30 years, was poorly transmitted by BrCA (3%). Furthermore, progeny virus from an infectious clone derived from the T36 genotype was also poorly transmitted by BrCA (<1%). In contrast, two other CTV isolates with the T36 genotype porpagated from field trees infected within the previous 18 months were moderately transmitted by BrCA (25-30%). A CTV isolate with the VT genotype, propagated by successive graft inoculation for 11 years was not transmitted by BrCA, while two other CTV isolates with the VT genotype, propagated from infected field trees, were moderately transmitted by BrCA (23-36%). These results indicate that virus transmission by BrCA is variable among CTV isolates from Florida. While our data indicates that the isolate genotype and the time spent in graft propagation without transmission by an aphid may play a role, no single factor is a specific indicator for virus transmission by BrCA.