Disease Note.

Differences in Reactions Among Tomato Spotted Wilt Virus Isolates to Three Resistant Capsicum chinense Lines. H. A Hobbs, Department of Plant Pathology and Crop Physiology, Louisiana Agricultural Experiment Station, Louisiana Stale University Agricultural Center, Baton Rouge 70803. L. L. Black, R. R. Johnson, and R. A. Valverde, Department of Plant Pathology and Crop Physiology, Louisiana Agricultural Experiment Station, Louisiana Stale University Agricultural Center, Baton Rouge 70803. Plant Dis. 78:1220. Accepted for publication 2 September 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1220D.

In 1992, a tomato spotted wilt virus (TSWV) isolate from tomato (Lycopersicon esculentum Mill.) in New Roads in southern Louisiana was found to produce chlorotic lesions on inoculated leaves of Capsicum chinense Jacquin PI 152225 and PI 159236, followed by systemic movement and mosaic symptoms. These two PIs in 1991 were reported to produce necrotic local lesions with no systemic virus movement upon inoculation with seven Louisiana TSWV isolates (1). In 1993, 61 TSWV isolates were collected from tomato, pepper, and weed hosts at five locations in Louisiana, and mechanically inoculated to the C. chinense PIs and to systemic hosts. Fifty-nine of 61 isolates produced necrotic local lesions with no systemic movement in the two PIs (typical), but two isolates (one from New Roads and one from Calhoun in north central Louisiana) produced chlorotic lesions and systemic symptoms (atypical). Progeny of selfed individual plant selections made from a third C. chinense line (Asian Vegetable Research and Development Center designation C00943) reacted the same as PI 159236 and PI 152225 when inoculated with typical and atypical isolates. No other host range susceptibility/resistance differences between typical and atypical isolates were observed. The TSWV-resistant tomato cultivar PS 55289 was resistant to all isolates. All isolates were positive in ELISA using the TSWV-L (lettuce) antiserum from Agdia, Inc., and antiserum produced to a Louisiana isolate of TSWV from tomato. Tospovirus isolates able to systemically infect PI 159236 have been reported from Brazil (2).