اثر افزایشی حضور (Subterranean clover stunt alphasatellite 1(C11 بر انتقال ویروس زردی بافت مرده باقلا (FBNYV) توسط شته Acyrthosiphon pisum

Faba bean necrotic yellows virus, a member of the genus Nanovirus (Family: Nanoviridae) is a multipartite virus with eight circular single-stranded DNA molecules (DNA-C, -M, -N, -R, -S, -U1, -U2, -U4) each about 1kb in size, which are packed individually in the small isometric viral capsids. In addition to their genomic components, nanoviruses might be associated with other single-stranded, circular DNA segments called Alphasatellites whose genome organization is similar to that of the DNA-R. Alphasatellites depend on their helper viruses for incapcidation, movement, and transmission. In order to investigate the effect of the presence of Subterranean clover stunt alphasatellite 1 (C11) on the transmission of FBNYV by Acyrthosiphon pisum, agroinoculation of faba bean seedlings (Vicia faba var Sevilla) was carried out using FBNYV infectious clones with/without the infectious clone of C11 alphasatellite. Then, the presence of all agroinoculated segments was confirmed by quantitative PCR in symptomatic plants. Transmission experiments were performed using these source plants in two treatments (with and without alphasatellite) and three replications (15 faba bean seedling in each replication). The percentage of infected plants compared to the total plants was calculated after the transmission tests and the effect of the presence of alphastellite on the transmission rate of the virus was investigated using Generalized Linear Model and R software. The results showed that at comparable virus loads in the source plants, FBNYV transmission rate by A. pisum is higher in the presence of C11 alphasatellite. The alphasatellite may affect the selection efficiency and enhance virus compatibility, thereby increase the virus transmission rate. These results are in contrast with the results of previous research on the role of the associated alphasatellite with Euphorbia yellow mosaic virus (EuYMV) on the transmission of this geminivirus by Bemisia tabaci, where the reduction of transmission rate was reported.