Submitted to: International Organization of Citrus Virologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2006
Publication Date: 1/10/2007
Citation: Ramos, C., Roistacher, C.N., Muller, G.W., Bederski, K., Rangel, B., Lee, R.F. 2007. Molecular Characterization of Citrus Tristeza Virus Isolates from Mild Strain Cross Protection Experiments in Peru. International Organization of Citrus Virologists Proceedings, 16th Conference, Pg. 492. Interpretive Summary: Strains of Citrus tristeza virus (CTV) exist in Peru which cause severe stem pitting on sweet orange and limes. Previous research was done to select mild strains which are useful for mild strain cross protection in Peru. We report here on the molecular characterization of five mild isolates of CTV collected from the field after being challenged by naturally occurring severe strains of CTV, plus two isolates from the field from trees not pre-inoculated with the cross protecting isolates of CTV.
Technical Abstract: Seven isolates of Citrus tristeza virus (CTV) collected from the Topara Nursery, Lima, Peru were established as in planta cultures in Madam Vinous sweet orange in the Exotic Citrus Pathogen Quarantine Greenhouse, Beltsville, MD. Two of the isolates were collected from non-cross protected plants; Peru isolates #6 and #14. Five of the isolates were collected from cross protected trees in the field: Peru #2 isolate L-2 collected from the L-1 tree at Topara, #3 is the R2 isolate used for Fukomoto sweet orange, #4 isolate L-2 collected from a navel with little pitting, #10 isolate Toapra-1 Key lime protective source collected from grapefruit, and #12 isolate collected from Minneola with deep pits. The isolates were genotyped using the multiple molecular markers method and the coat protein gene sequenced and the sequences compared to determine relatedness of the isolates. Biological indexing on sweet orange and grapefruit will be done using the in planta cultures.