Protection between strains of Passion fruit woodiness virus in sunnhemp

Abstract

The main objective of the present study was to evaluate the effect of the sunhemp (Crotalaria juncea) host species on the protective ability of two mild strains of Passion fruit woodiness virus (PWV), named F-101 and F-144, which had failed to protect passion flowers (Passiflora edulis f. flavicarpa) in previous experiments. The nucleotide sequences of the capsid protein (CP) gene and the 3'-non-translated region (3'-NTR) of these mild strains and the severe strain of PWV-SP were compared to confirm their relationship. The results of two protective tests with sunhemp plants in the greenhouse and one test under field conditions showed that all plants infected with either mild strain were protected against infection and/or symptom expression of the severe strain of PWV-SP. Evaluation of the relative concentration of the mild strains in sun hemp leaves showed an apparent uniformity in virus distribution in the leaf tissues, different than that which was previously reported for these mild strains in passion flower leaves. These results agree with previous studies that showed the effect of the concentration of the protective strains and the host species in the protection process.

Protection between strains of Papaya ringspot virus: type w in zucchini squash involves competition for viral replication sites

“…As a result, in regions where the mild strains were irregularly distributed or were found at low concentrations, there may be free sites for superinfection with the severe strain to occur; because the severe strain is more competitive, it later invades the plants systemically. This breakdown on protection, however, did not occur in studies with sunn hemp plants (Crotalaria juncea L.) infected with the same mild strains of PWV (Novaes & Rezende, 2005). In this case, after analyzing the concentrations of mild strains in the plant tissues, the authors suggested that protection effectiveness was apparently associated with a more uniform concentration and distribution of mild strains in the tissues of this plant species.…”

Partial efficacy of early and temporary roguing to manage woodiness disease in pilot crops of passion fruit

“…The following aphid species are reported CABMV vectors in Brazil: Aphis craccivora , A. fabae , A. gossypii , Myzus persicae , Toxoptera citricidus and Uroleucon ambrosiae (Garcêz et al, 2015; Inoue et al, 1995). Under experimental conditions, A. fabae and A. solanella showed 40% efficiency in transmitting CABMV, whereas U. sonchi did not transmit the virus (Garcêz et al, 2015).…”