Pepper Mild Mottle Virus - Host and Symptoms

Host and Symptoms

The Pepper Mild Mottle Virus is the major viral pathogen of peppers (Capsicum spp.). The host range of PMMoV include most cultivars and species of pepper (Capsicum spp.). This virus strain does not infect tomato, eggplant, or tobacco; however, other members of the genus Tobamovirus can infect these other hosts PMMoV is one of at least 4 different species of Tobamovirus that infect peppers. The others include Tobacco mosaic virus (TMV), Tomato mosaic virus (ToMV) and Tobacco mild green mosaic virus (TMGMV).

This pathogen is known to occur throughout the world and it frequently results in significant crop losses or reductions in both field and greenhouse plantings. The virus has been identified in places like Australia, Japan, China, Taiwan, Europe, and North Africa. Since 1997, PMMoV has been the cause of many major outbreaks in the southeastern states namely Georgia and Florida.

Symptoms caused by this pathogen vary based on the specific host cultivar; however, a majority of the symptoms are very similar between the different hosts. Symptoms usually include various degrees of mottling, chlorosis, curling, dwarfing, and distortion of the fruit, leaves, and even whole plants. The symptoms on fruit include: a reduction in size, mottling and color changes, and an obvious distorted and lumpy appearance. Also, many times brown necrotic streaks or splotches can be seen on the leaves and fruit. The symptoms can easily be seen on new growth, and they are far more pronounced if the plant was infected when it was young rather than when it was older.

This disease is harmful because of the mild foliar symptoms (chlorosis, necrosis, etc.) and due to this many times the pathogen goes unnoticed until the more evident symptoms on the fruit appear. This is why there are higher yield losses because symptoms only become evident during the fruiting stage right before the crops are supposed to harvested.