Indexed on: 01 Jul '14Published on: 01 Jul '14Published in: Letters in Applied Microbiology
Resistance-breaking strains of Tomato mosaic virus (ToMV) are emerging in many countries, including Japan. We examined whether deep ultraviolet (UV) irradiation on tomato plants using light-emitting diodes (LEDs) could suppress the expression of ToMV symptoms. We also investigated the optimum wavelength and radiant exposure for suppressing the disease effectively in tomato plants. Among the three wavelengths tested, UV irradiation at 280-290 nm had a relatively high suppressive effect on ToMV and resulted in a low incidence of UV damage. Pre-inoculation exposure to UV was effective in suppressing viral disease, indicating that acquired resistance was induced by UV irradiation. UV-B fluence of 0·7-1·4 kJ m(-2 ) day(-1) at wavelengths of 280-290 nm suppressed ToMV effectively without significant UV damage.Disease caused in tomato plants by resistance-breaking Tomato mosaic virus (ToMV) could be suppressed by ultraviolet (UV)-B irradiation using light-emitting diodes (LEDs). This paves the way for the future management of plant viral diseases using deep UV LEDs.