Purificação e caracterização de um isolado do vírus do endurecimento dos frutos do maracujá e sua incidência na Ibiapaba

• Ano de defesa: 1992
• Autor(a) principal: Bezerra, Desirée Rolim
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Agronomia
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/46137

A virus isolate obtained from Passiflora edulis f. flavicarpa (Yellow passionfruit) grown on the Ibiapaba Mountains in the State of Ceará, Brazil from 3°30' to 40°42' South Latitude and 40°40' to 41°25' West Longitude, was studied on the basis of its serological characteristics, stability in sap, molecular weight of its capsidial protein, aphid transmission, symptomatolgy, cytopatological effects in infected plants and host range. According to the obtained results, and the low degree of severity detected in the passionfruit orchards, the virus was identified as a mild strain of passionfruit woodiness virus (PWV), able to induce mosaic, blistering and leaf deformations in yellow passionfruit, without causing woodiness of the fruits. The strain of PWV studied was able to infected 14 dicotiledon plant species, distributed in 5 botanical famiIies that reacted in different ways, with systemic or local infections. The majority of infected species belongs to the family Leguminosae, among which Macroptilium lathyroides was selected for maintainance and propagation of the virus for its purification. The choice of the plant species combined with the method adapted for purification yeIded 18,24 mg of virus/Kg of fresh leaves and an antiserum of good quality. A high concentration of the virus in M. lathyroides was also observed in the infected plant regrowth which was colleted 20 days after the first samples and afforded a second purification. The virus was transmitted with 50% of efficiency by Aphis fabae, from passionfruit plants to M. lathyroides, in a non-persitent manner. Light microscope observations of epidermal cells from infected plants indicated the presence of inclusions similar to those described for the potyviruses. Polyacrilamide gell eletrophoresis with sodium dodecil sulfate (SDS) of purified virus preparation revealed the presence of a main component protein with molecular weight of 36 kDa. A smaller protein of 29 kDa was also detected in less concentration, which probably correspondes to an enzimatically degradation of the capsidial protein of 36 kDa, during the process of purification and storage of the virus. Serological tests showed that the strain of PWV studied is serologically related to cowpea aphid-borne mosaic virus and another potyviruses not totally characterized, isolated from: Canavalia ensiformes (Poty-CE); Cassia occidentales (Poty-CT); Glycine max (Poty-soja); Macroptilium atropurpureum (Poty-siratro); M. lathyroides (Poty-ML) and Sesamum orientale (Poty-SO).