Pepper mild mottle virus in jalapeno pepper in Georgia

First Report of Pepper mild mottle virus in Jalapeno Pepper in Georgia

Natalia Martínez-Ochoa, David B. Langston, and Stephen W. Mullis, Department of Plant Pathology, University of Georgia, Coastal Plain Experiment Station, Tifton 31793-0748; and James T. Flanders, University of Georgia Cooperative Extension Service, Grady County, Cairo 31728

Pepper mild mottle virus (PMMoV) of the genus Tobamovirus occurs worldwide and can drastically reduce fruit yield in chili and bell peppers (2,3). In the southeastern United States the virus has been reported since 1997 in Florida, where it was first identified on ornamental peppers and more recently in several bell pepper cultivars in commercial fields (1). In October of 2002, an entire field of jalapeno pepper (Capsicum annuum L.) in Grady County in Georgia was affected by a virus-like disease, where most fruits were severely mottled, reduced in size, deformed, and some showed off-colored sunken areas (Fig. 1). Disease incidence on plants ranged from 20 to 80% and resulted in a 50 to 100% yield loss.

Fig. 1. Jalapeno peppers showing typical symptoms caused by PMMoV (left) and Tomato spotted wilt virus (TSWV) (right).

Fruit and leaf tissues from several plants were tested by compound direct ELISA with commercial antisera for PMMoV (Agdia Inc., Elkhart, IN). Jalapeno pepper seeds of the variety Agriset 4001, from the same seed lot used in the field, were obtained from the grower and also tested by ELISA. All tissues and seed samples tested positive for PMMoV. Seeds from the lot testing positive were planted in individual pots in the greenhouse at 25 to 35°C using Berger peat moss BM1 (Saint Modeste, Quèbec, Canada). Subsequent developing tissues (leaves, stems, roots, and fruits from 16 plants) were tested for PMMoV, and 75% were positive, confirming transmission through seed. The virus was also mechanically transmitted by sap inoculation (from leaves and symptomatic fruit tissues) into leaves of several healthy seedlings of jalapeno pepper Grande, sweet bell pepper green Colossal, and tobacco K-326 (with transmission rates of 25, 63 and 50%, respectively) under greenhouse conditions as described earlier. This is the first report of seed-transmitted PMMoV affecting jalapeno peppers in Georgia. These findings suggest that seed companies may need to implement new screenings for PMMoV in jalapeno pepper.

Literature Cited

1. Adkins, S., Lamb, E. M., Roberts, P. D., Gooch, M. D., Breman, L., and Shuler, K. D. 2001. Identification of Pepper mild mottle virus in commercial bell pepper in Florida. Plant Dis. 85:679.

2. Green, S. K. 2003. Pepper mild mottle virus. Pages 32-33 in: Compendium of Pepper Diseases. K. Pernezny, P. D. Roberts, J. F. Murphy, and N. P. Goldberg, eds. American Phytopathological Society, St. Paul, MN.

3. Wetter, C. 1984. Serological identification of four tobamoviruses infecting pepper. Plant Dis. 68:597-599.