Detection Of Citrus Tatter Leaf Virus (CTLV) By Semi-nested RT-PCR

Citrus tatter leaf disease induced by citrus tatter leaf virus (CTLV) was first reported in latently infected Meyer lemon in 1962. CTLV can infect most citrus cultivars latently. Bud-union incompatibility, stunting, chlorosis are shown in the trees grafted on trifoliate orange or trifoliate orange hybrid. It is known that CTLV is widespread in China. CTLV-susceptible rootstocks is rapidly increasing. It could become a significant problem in the citrus industry of China. Biological indexing is the traditional method for the detection of the disease and has many limitations such as time-consuming, season- and green house-dependant. The development of rapid and reliable detection methods for CTLV are in need. CTLV in different parts and orientations of a infected tree were detected by Semi-nested RT-PCR developed by Hailstones et al(2000). Annual detection of CTLV in four infected varieties was done by the Semi-nested RT-PCR in this study. Partial sequence analyses was carried out for CTLV isolates from the four infected varieries. Semi-nested RT-PCR was used to detect CTLV in 23 imported citrus varieties from "948" project and 788 candidate mother trees from "Bai Wan Dun" project.Following conclusions can be drawn from this study:1. Different parts of a CTLV-infected tree were subjected to the Semi-nested RT-PCR analysis.The results showed that CTLV was detectable in all sampled parts except old bark. Three different orientations of CTLV-infected trees of 14-1 and 14-2 were analysed . The results showed that CTLV wasn't detected in one orientation of a 14-2 tree. It can be concluded that the distribution of CTLV in infected trees is uneven.