A sensitive method for detecting bamboo mosaic virus (BaMV) and establishment of BaMV-free meristem-tip cultures

A sensitive method was used to detect bamboo mosaic virus (BaMV) and its associated satellite RNA (satBaMV) by ³²P- and digoxigenin (Dig)-labelled probes synthesized from cDNA clones of BaMV genomic (L probe) and satBaMV (S probe) RNA. Both the ³²P- and Dig-labelled L and S probes could detect as little as 490 pg of BaMV viral RNA by slot- and dot-blot hybridization. In infected leaf extracts, ³²P-labelled L and S probes detected virus at 25-fold higher dilutions than Dig-labelled probes, which were also successfully used to detect BaMV infection in plants derived from meristem-tip culture. However, immunoassays failed to detect BaMV in meristem culture. By dot-blot hybridization assays, 25% of the seedlings were shown to be virus-free. These results suggest that a highly sensitive method for the detection of BaMV infection is required for the establishment of BaMV-free cultures. Meristem-tip culture also provides an efficient method for obtaining virus-free bamboo plants.