LIGHT-INDUCED EFFECTS ON EARLY INFECTION WITH CARNATION MOTTLE VIRUS

Abstract

Exposure of Chenopodium amaranticolor, Gomphrena globosa, and Dianthus barbatus to light before and/or after mechanical inoculation with carnation mottle virus exerted marked effects on virus establishment, multiplication and host symptom response. A preinoculation dark treatment promoted large numbers of local lesions when coupled with a subsequent postinoculation light period. A preinoculation light treatment reduced the number of lesions even with a postinoculation light period. Continuous darkness during virus incubation prevented or delayed the appearance of lesions. Continuous darkness also depressed the amount of serologically detectable virus in inoculated leaves of D. barbatus and the virus was either confined to the inoculated leaves or its translocation to uninoculated leaves was delayed.