Submitted to: International Organization of Citrus Virologists Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/15/2005
Publication Date: 9/15/2005
Citation: Hilf, M.E. 2005. Partial sequence characterization of citrus tristeza virus that overcomes the general resistance to ctv expressed in poncirus trifoliata. International Organization of Citrus Virologists Proceedings. Interpretive Summary:
Technical Abstract: Previous work (T.E. Dawson and P.A Mooney, Proc. 14th IOCV, 69-76, 2000) provided evidence that Citrus tristeza virus (CTV) recovered from commercial orchard trees grown in the Kerikeri district of New Zealand replicated in graft inoculated seedlings of Rubidoux or Flying Dragon trifoliate orange (Poncirus trifoliata), which express a general resistance to systemic infection by CTV. Citrus budwood infected with this CTV was used to inoculate Madam Vinous sweet orange seedlings for propagation and addition of this isolate to the Exotic Citrus Pathogen Collection held at the Beltsville Agricultural Research Center, Beltsville, Maryland. Because of the importance of the P. trifoliata resistance gene in both scion and rootstock breeding programs, a preliminary analysis was undertaken to characterize the genome of this isolate of CTV. An immunocapture-RT-PCR procedure using degenerate primers yielded ~6150 nucleotides from contiguous and non-contiguous portions of the 1a open reading frame of this CTV propagated in Madam Vinous sweet orange. Nucleotide sequence comparisons of these clones showed ~90% identity to the Florida T36 isolate and phylogenetic analysis indicated a closer relationship with T36 than with the other CTV genomic sequences.