Comparison of short- and long-feed transmission of the cauliflower mosaic virus Cabb-S strain and S delta II hybrid by two species of aphid: Myzus persicae (Sulzer) and Brevicoryne brassicae (L.).

The cauliflower mosaic virus (CaMV) hybrid S delta II, partially deleted in ORFII, loses its transmissibility by the aphid Myzus persicae on 5-min acquisition feed. We have also shown that it is not transmitted after 8-h acquisition feed. The same occurs with Brevicoryne brassicae.

Differentiation of peanut clump virus serotypes by monoclonal antibodies.

A panel of monoclonal antibodies (mAb) produced against peanut clump virus (PCV) was used to characterize five serotypes of the virus. Four different formats of enzyme-linked immunosorbent assays (ELISA) were compared to establish the most suitable one for diagnosis of infected plants and for serotype differentiation. Since most mAb retained their activity when used for coating microtitre plates, a dual mAb-type assay was found to be most suitable.

A second cauliflower mosaic virus gene product influences the structure of the viral inclusion body.

We have used electron microscopy of thin sections and experiments on isolated viroplasms to compare the properties of four strains of cauliflower mosaic virus (CaMV), three of which were partially or completely deleted in open reading frame (ORF) II. Our results confirm that this gene is required for aphid transmissibility and show that the product of ORF II influences the firmness with which virions are held within the viroplasm. Analysis of the proteins in the viroplasms showed that a mutant with a partial deletion in ORF II produced a protein smaller than the normal ORF product.