Location: Vegetable ResearchTitle: Revisiting seed-transmissibility of Sweet potato leaf curl virus, a begomovirus infecting sweetpotatoes
|ANDREASON, SHARON - Orise Fellow|
|OLANIYI, OMOTOLA - Orise Fellow|
|JACKSON, D. MICHAEL - Retired ARS Employee|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2020
Publication Date: 8/3/2020
Citation: Andreason, S., Olaniyi, O., Wadl, P., Williams, L., Jackson, D.M., Simmons, A., Ling, K. 2020. Revisiting seed-transmissibility of Sweet potato leaf curl virus, a begomovirus infecting sweetpotatoes. Plant Health 2020 Online.
Technical Abstract: Sweet potato leaf curl virus (SPLCV), a begomovirus (Geminiviridae) transmitted via vegetative propagation of sweetpotato or by the whitefly species Bemisia tabaci, threatens global sweetpotato production. Complicating management of SPLCV is the disputed publication of seed transmission of this begomovirus, a group of viruses which before 2015 were not reported to be seed transmissible. That report prompted an investigation into the validity of seed transmission of SPLCV. In this study, experiments were conducted on over 26,000 individuals. Conventional and quantitative real-time polymerase chain reaction (PCR) were performed to detect the presence of virus on the seed coat (seed-borne; contaminant) and subsequently in germinated seedlings. Virus was detected on seed coats in each year of the study. Year one, circa (ca.) 200 seedlings were tested, and no seed transmission was detected. Year two, ca. 5,000 seedlings were tested, and a small number of samples were positive for SPLCV; however, adult whiteflies were observed in the greenhouse, therefore transmission via the seed versus the vector could not be determined. Year three, ca. 20,000 seedlings derived from breeding seeds of SPLCV-infected plants were examined, and no seed transmission was detected. Year four, 900 seedlings were grown, again with no seed transmission detected. Vector transmission tests demonstrated successful transmission of SPLCV to seedlings by viruliferous B. tabaci, although at low efficiency (0.02%). Repeated large-scale, multi-family seedling grow-out experiments over successive years did not support seed transmission of SPLCV.