Detecção sorológica de cowpea aphid-borne mosaic virus em diferentes espécies de Passiflora e caracterização biológica de um isolado obtido de Passiflora alata

Abstract

Species belonging to the Passiflora genus are popularly known as passion fruit. They are important mainly for ornamental and medicinal use and for commercialization of their fruits in nature and for industrialization. Among the agents that cause disease in Passiflora, viruses are very important. The passion fruit woodiness disease, caused by cowpea aphid-mosaic virus (CABMV) stands out for its widespread and management difficulty. Therefore, the main objective of this work was the detection of CABMV in different species of Passiflora and the biological characterization in infected Passiflora alata plants. Seventeen samples belonging to the species of P. edulis, P. watsoniana, P. cincinnata, P. alata, P. rupestris, P. subrotunda, P. serrato-digitata, P. galbana, P. vesicaria and an ornamental hybrid cv. BRS Céu do Cerrado from a cross between P. edulis x P. incarnata showing symptoms that may be associated with viral infections. The samples were submitted to serological detection by Dot-Elisa, using specific anti-CABMV primary antibody and anti-Igg secondary antibody conjugated with alkaline phosphatase enzyme (AS-0417, DSMZ, Germany). PCR was performed using universal primers pAL1v1978 (5'GCA TCT GCA GGC CCA CAT YGT CTT YCC NGT 3') and Par1C496 (5' AAT ACT GCA GGG CTT YCT RTA CAT RGG 3') to detect co-infection with begomoviruses in four samples of P. edulis and P. alata. The isolated RPA-1 CABMV, obtained from P. alata from producing areas from Recife was analyzed by Western Blot to confirm the viral presence. In addition, the biological characterization of the isolate RPA-1 was carried out by mechanically inoculating the virus in the following species: P edulis, P. suberosa, P. vesicaria, Phaseoulus vulgaris cv. Preto 193, Glycine max, Vigna unguiculata cv CNC 0434, V. unguiculata cv. TVu 2331 and Nicotiana benthamiana. Among all samples, 76% were positive for CABMV, namely P. edulis, P. alata, P. cincinnata, P. watsoniana, P. galbana, P. subrotunda and also the ornamental hybrid cv. BRS Céu do Cerrado. No sample was positive for begomovirus infection. The isolated RPA-1 was detected by western blot for the presence of CABMV that was able to infect plants of N. benthamiana, P. edulis, P. vulgaris cv. Preto 193, but was not able to cause symptoms in Glycine max, Vigna unguiculata cv CNC 0434, V. unguiculata cv. TVu 2331. Despite this experiment lead to symptoms in P. vesicaria, it was not possible to detect the CABMV in the sample. These results may indicate that the inoculum used in the mechanical inoculation experiment may contain another virus.