Latent and incubation periods of Cowpea aphid-borne mosaic virus in passionflower.
David Marques de Almeida Spadotti: University of São Paulo - ESALQ
<div>In Brazil,<em> Cowpea aphid-borne mosaic virus</em> (CABMV, genus <em>Potyvirus</em>) is widespread in yellow passion fruit (<em>Passiflora edulis</em> f. <em>flavicarpa</em>) causing woodiness disease. Currently, there are no effective and long-lasting forms of disease control. The objective of this work was to determine the latent and incubation periods of the disease to subsidize the roguing of infected plants as an alternative for disease management. 140 and 120 passion fruit plants were used on each assay, respectively. CABMV isolates from the states of São Paulo, Bahia and Rio de Janeiro were used, and the virus was sap transmitted to health plants. Latent period was evaluated throughout virus recovery from new developed leaf, 3 to 7 days after test-plants inoculation, whereas incubation was evaluated through symptoms and PTA-ELISA. The latent period ranged from 3 to 7 days (average 6 days), and the incubation 4 to 15 days (average 8 days). The same assay was performed with the São Paulo isolate of CABMV and transmission with the aphid <em>Myzus persicae</em> and the results were similar (average latent and incubation periods 8 and 9 days, respectively). Despite the variability of isolates, greenhouse environmental conditions, and inoculation methods, the latent and incubation periods of CABMV are very close, evidencing that the roguing of symptomatic plants can be consistently used to decrease source of inoculum of the virus, consequently diminishing secondary spread.</div>
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