To provide more efficient conditions for a method, said method comprising using, as a medium,a plant, which belongs to a specific family such as Solanaceae and is graft-compatible with different families, and allowing a character regulator to function in a plant belonging to a different family. A plant virus for producing a character regulator is selected as a substance to be delivered and then the selected plant virus is delivered, through a plant which belongs to a specific family such as Solanaceae and is graft-compatible with different families, to a plant belonging to a different family.Se proporcionan condiciones más eficientes para permitir que un regulador de característica funcione, al utilizar una planta inter-familia-injertable de una familia específica, tal como Solanaceae, como un medio, en una planta que pertenece a una familia diferente de aquella del medio； un virus de planta para producir un regulador de característica se selecciona como el medio de suministro, y es suministrado a una planta de diferente familia a través de una planta interfamilia- injertable de una familia específica, tal como Solanaceae.
