Elimination of Bean common mosaic virus using an electrotherapy technique

Bean common mosaic virus (BCMV) is a major seed transmitted virus of common bean (Phaseolus vulgaris). The use of virus-free germplasm is a prerequisite for production of certified seeds, which is an important disease control measure. In this study, the efficiency of electrotherapy in eliminating BCMV and producing virus-free plants in two common bean cultivars, Khomein and Capsouli, was evaluated. Nodal cuttings of infected bean plants were exposed to electric currents of 5, 10 and 15 mA for 10 minutes and planted in vitro. One month old regenerated plantlets were tested by a Double Antibody Sandwich (DAS)-ELISA method for BCMV infection. The three intensities of electric current resulted in mean virus elimination percentages of 37.2%, 45.5% and 71.9% and mean plant regeneration of 79.5%, 68.6% and 58.4%, respectively. The Therapy Efficiency Index for the three electrotherapy treatments was estimated as 28.9, 29.2 and 39.1 in cv Khomein and 26.9, 33.3 and 44.8 in cv Capsouli, respectively. Based on the Therapy Efficiency Indices, an electric current of 15 mA for 10 min was the most effective treatment in both cultivars. The technique developed in this study can be a useful procedure for the production of virus-free germplasm and/or nucleus seed stock in crop plants infected with seed-borne viruses.