Abstract:

For the preliminary study on the suppression of Citrus tristeza virus（CTV）genotypes by different citrus cultivars. Four genotypes of CTV were graft-inoculated to‘Symons’Sweet orange，‘Mexican Lime’，‘Duncan’grapefruit and‘Chandler Pummelo’. The results of RT-qPCR showed that ‘Mexican Lime’was most suitable for the survival of these four CTV genotypes. The cope levels of VT，T3 and T36 genotypes in‘Duncan’grape fruit were much more lower than in other citrus cultivars. Furthermore，T36 genotype was reduced significantly by all of the citrus cultivars. Sequence analysis indicated that CP gene of VT genotype had frequent mutation in sweet orange.

Key words: Citrus, cultivar, Citrus tristeza virus, genotype, RT-qPCR, sequence analysis