Vaccinations and challenge inoculations in greenhouse. To study the effect of
plant age on the efficacy of the vaccine
(that is, the age at which plants could be
inoculated and achieve maximum numbers
of plants infected), pepper (Capsicum annuumcv. California Wonder) and melon
(Cucurbita melocv. Janus des Canaries)
plants were mechanically inoculated with
CMV-S genomic RNA and S-CARNA 5
(the vaccine) at 20 µg/ml in 0.03 M
Na2HPO4
at three different stages of development (i.e., cotyledon, first true leaf, and
4-leaf stage).