RESUMO
A carlavirus was found to be widespread in commercial passionfruit (Passiflora edulis) plantings in New South Wales and Queensland. The particles observed were flexuous rods with mean dimensions of 651 × 12 nm. The particles often occurred in cells as aggregates but were never associated with pinwheel inclusion bodies, as is typical with passionfruit woodiness potyvirus. The particles showed a strong affinity (by immunoelectron microscopy) for antiserum prepared against Passiflora latent carlavirus (PLV) from Germany but increasingly less affinity for antisera against potato viruses S and M and PLV from the United States. Survey results indicated that PLV has been present in Australian passionfruit for more than 10 years and is widespread in most commercial cultivars in New South Wales and Queensland. The virus was twice found in wild Passiflora suberosa, once in wild P. subpeltata, and once in a feral seedling of P. edulis near an infected planting of P. edulis.
RESUMO
A procedure based on the polymerase chain reaction (PCR) has been developed to classify cucumber mosaic cucumovirus (CMV) isolates accurately into two subgroups. Two CMV-specific primers that flank the CMV capsid protein gene were used to amplify a DNA fragment of approximately 870 bp. Restriction enzyme analysis of this fragment produces distinct restriction patterns that assign the CMV isolate into one of two subgroups. These two restriction groups correlate with the previously established CMV subgroupings; this PCR-based method may provide a simple alternative to the serological assays used for typing CMV isolates.
Assuntos
Vírus do Mosaico/classificação , Reação em Cadeia da Polimerase , RNA Viral/genética , Sequência de Bases , Capsídeo/genética , Clonagem Molecular , Dados de Sequência Molecular , Vírus do Mosaico/genética , Oligodesoxirribonucleotídeos/genética , Plantas/microbiologia , Mapeamento por RestriçãoRESUMO
Electrophoresis on 5% polyacrylamide was used to analyze dsRNAs of 26 cucumber mosaic virus isolates propagated in Nicotiana tabacum. There was variation between isolates in the migration of each of the dsRNAs 1, 2, and 3. Comparison of the dsRNA profiles enabled each isolate to be allocated to 1 of 7 distinct dsRNA profile types. Two distinct and readily distinguishable isolates were mixed in planta and dsRNA from these infected plants compared with in vitro mixtures of them. All bands from both types were present, indicating that the differences were real and reproducible. This method is of value as a means of classifying cucumber mosaic virus isolates, as it more closely reflects a range of biological characteristics than do other methods currently used.
