United States Department of Agriculture, Agricultural Research Service, United States Horticultural Research Laboratory, 2001 South Rock Road, Fort Pierce, FL 34945, USA
Three aspects of the infection process of a new tobamovirus species, Hibiscus latent Fort Pierce virus, recently isolated from hibiscus in Florida, were examined: (i) transmission efficiency of rub-, slash-, and cut-inoculation for two hibiscus cultivars, Pink Versicolor and Brilliant Red; (ii) distribution within infected hibiscus plants; and (iii) treatments to prevent infection during plant propagation and pruning. Rub-, slash-, and cut-inoculation methods were all effective and yielded infection rates of 66, 74, and 70%, respectively, in Pink Versicolor and 50, 56, and 38%, respectively, in Brilliant Red. Analysis of virus distribution in infected plants over time revealed that the virus moved from the place of inoculation to the roots and then toward the bottom (oldest) leaves of the plants. Virus was found in all leaves on branches of Brilliant Red plants at 210 days postinoculation, whereas it remained restricted to the bottom and middle leaves of Pink Versicolor plants at 290 days postinoculation. Although several treatments of tools reduced infection of hibiscus during experiments mimicking plant propagation and pruning, 10% (wt/vol) sodium hypochlorite and 20% (wt/vol) nonfat dry milk completely prevented infection.