Detection of Poplar Mosaic Carlavirus (POPMV) by Immuno-Capture RT-PCR

Abstract

Poplar mosaic virus (PopMV) is a widespread disease of poplar trees (Populus sp.), where it can causing severe growth losses. Typical symptoms are a mosaic or diffuse spotting in mature leaves and, in severely responding clones, necrosis of veins and leaf stalks or splits on the stem (Biddle and Tinsley, 1971). Viruses of forest trees are often difficult to detect due to their low virus concentration, their inhomogenous distribution in the plant and phenolic compounds in plant extracts. For reliable diagnosis several samples from each plant have to be tested either as single samples by ELISA or gathered as one sample by RT-PCR. Immuno-capture RT-PCR is a highly sensitive method for the detection of specific viruses. We applied this sensitive method in the detection of CLRV (Buttner et al., 1996) and PopMV. Immuno-capture RT-PCR is sensitive enough to detect minute amounts of a virus in small samples e.g. CLRV in single birch seeds or bugs (Kleidocerys resedae Panzer), sampled from infected trees and in highly diluted plant extracts (Werner et al., 1996). The advanced sensitivity of this diagnostic tool allows the combination of several samples in one charge for virus detection in woody plants. We show that the very inhomogenous distribution of PopMV in poplar leaves makes this procedure nessessary to obtain reliable diagnostic results.