In 1996, an isolate of Cucumber mosaic virus (CMV) obtained from banana in São Paulo State, was partially characterizated. In order to establish its CMV subgroup, ELISA, RT-PCR, RFLP, and sequencing of a fragment of genomic RNA were used. Infected leaf samples that have been stored since 1994 on calcium chloride at -20 °C were inoculated in Nicotiana glutinosa plants. Ten days after inoculation, the leaves showing mosaic symptoms were used for ELISA and total RNA extraction. The ELISA results were positive for the antiserum against CMV subgroup I. By RT-PCR, with primers designed to anneal the conserved regions of the coat protein gene3' end, a 486 base pair DNA fragment was amplified. The RFLP results with EcoRI, HindIII, BamHI and MspI enzymes showed a typical digestion pattern for subgroup I. These results were confirmed by sequencing the PCR product showing a homology of 96 to 98% with the subgroup I CMV isolates. Based on symptom expression on the differential host Vigna unguiculata, the isolate was confirmed as belonging to the subgroup Ia.
