NASCIMENTO, Ana Verônica Silva do.; SANTANA, Enilton Nascimento de.; BRAZ, Antonio Sergio Kimus.; ALFENAS, Poliane Alfenas.; PIO-RIBEIRO, Gilvan.; ANDRADE, Genira Pereira de.; CARVALHO, Murilo G.; ZERBINI JUNIOR, Francisco Murilo.
Resumo:
Leaf samples of yellow passionfruit (Passiflora edulis f. flavicarpa)
displaying fruit woodiness symptoms were collected in seven Brazilian states and
the Federal District. Viral infection was confirmed by host range and ELISA,
and fourteen viral isolates were obtained. All isolates were capable of infecting
several leguminous host species, although differences in symptom severity were
noticeable. Woodiness symptoms were reproduced in yellow passionfruit, and
mosaic symptoms were induced in common bean. All isolates infected cowpea,
reported as a non-host of passion fruit woodiness virus (PWV). Indirect ELISA
demonstrated that all isolates were serologically related to each other and also
to cowpea aphid-borne mosaic virus (CABMV). The complete sequence of the
capsid protein was determined for all isolates. Comparison of these sequences with
those of other potyviruses indicated the highest identity with CABMV isolates
(85 to 94%). Identity with PWV isolates ranged from 54 to 70%. Phylogenetic
analysis grouped all of the Brazilian isolates in a monophyletic cluster with
the CABMV isolates, clearly distinct from the PWV isolates. Furthermore, this
analysis demonstrated that a group of previously characterized isolates from Brazil
that had been designated as PWV should be reclassified as CABMV. Together,
these results provide unequivocal evidence that, in Brazil, passionfruit woodiness
disease is primarily caused by CABMV. The presence of PWV in Brazil has yet
to be confirmed.