First report of a mixed infection of pepper mild mottle virus and tobacco mild green mosaic virus in pepper (Capsicum annuum) in the United States.
In 2015, sweet pepper (Capsicum annuum) plants from a demonstration garden at the Louisiana State University Agricultural Centre Botanic Garden in Baton Rouge were showing leaf cupping and yellow mottle symptoms. Foliar samples from three plants showing symptoms were collected and each sample was used in mechanical inoculations to single plants of bell pepper cv. Marengo. Three weeks after inoculation, all plants developed leaf cupping, mottle, and later fruit discoloration and malformation. Results of ELISA tests and reverse transcription-PCR reactions revealed a mixed infection of Pepper mild mottle virus (PMMoV) and Tobacco mild green mosaic virus (TMGMV). Both PMMoV and TMGMV are seed transmitted and cause diseases in pepper worldwide. Mixed infections of PMMoV and TMGMV have been reported to occur in open-field pepper crops in Panama. In Louisiana, peppers (C. annuum and C. frutescens) are economically important crops. This is thought to be the first report of PMMoV and TMGMV in Louisiana and the first report of a mixed infection of these two viruses in pepper in the USA.