Grapevine virus A (GVA) and Grapevine virus B (GVB) are involved in the Kober stem grooving and grapevine corky bark diseases, respectively. This work reports the molecular detection of isolates of GVA (GVA-SP) and GVB (GVB-C-SP and GVB-I-SP) in grapevines (Vitis spp.) and tobacco (Nicotiana occidentalis) by non-radioactive molecular probes. The digoxigenin-labeled probes were generated by RT-PCR using specific primers to the coat protein genes. Total RNA was extracted from 45 plants of several grapevine varieties and from 13 plants of tobacco mechanically inoculated with GVB. The RNA extracted from infected plants, considered infected by biological indexing, reacted to the cDNA probes while there was no hybridization with healthy plants. These results were also confirmed by RT-PCR experiments. The use of the cDNA probes hybridization was proved to be efficient in detecting both GVA and GVB with high specificity and sensitivity. However, mature leaves and dormant cuttings should be preferably used in diagnostic tests of GVB and GVA, respectively.
Vitis; Vitivirus; stem grooving; grapevine cork barky; Kober stem grooving
