Novel resistance to tobacco etch virus in peppers (Capsicum spp.)

Abstract Tobacco etch virus (TEV) is a pathogen that affects peppers all over the world. It causes serious losses, and it is difficult to control since it has many aphid vectors. Because these aphids move around, and transmit TEV in a non-persistent manner, many applications of pesticides would be necessary to reduce TEV incidence, leading to more environmental pollution and destruction of beneficial predator insects. Therefore, host plant resistance is the best solution for TEV. Peppers ( Capsicum spp.) exhibit ample genetic variability. Numerous resistance genes against TEV have been documented over the past 70 years. However, these are all recessive in nature. This has made deployment in hybrids more difficult and therefore, not many TEV resistant pepper cultivars have been released. The pepper breeding project at Texas A&M AgriLife Research screened over 200 USDA plant introductions from 6 species for resistance to TEV with both natural field infection and controlled inoculations at Weslaco. ELISA tests and visual assessments of symptoms of the virus in the plants were performed. Four accessions not previously characterized as resistant were identified with mild or no symptoms. These included two C. chinense and two C. baccatum accessions. An interspecific population of C. annuum ‘serrano’ x C. baccatum var. baccatum was developed to study the resistance from that wild type. Chi-square analysis indicated that resistance is controlled by a single, dominant gene, which will facilitate the development of resistant varieties using traditional breeding procedures such as backcrossing.