Spotted-wilt development in resistant and susceptible Lycopersicon species.

Abstract

Studies have been made of the development of the spotted-wilt virus In the inoculated leaves and non-inoculated parts of three Lycopersicon species. At temperatures of 60°F to 87°F. L. pimpinellifolium (Porter's strain), L. peruvanum, and the L. esculentum variety Rey de los Tempranos, exhibit different degrees of resistance to virus multiplication when compared with the susceptible Bonny Best variety. Infected plants of Porter's strain and Rey de los Tempranos are able to develop new growth free from virus. Resistance appears to depend on the presence of a virus-inactivating system which functions more actively when plants are maintained at a temperature of 90°F. Although the resistance of Porter's strain can be transmitted to hybrids, Rey de los Tempranos appears more promising as a parent for the development of spotted-wilt-resistant tomato varieties. A method for the selection of the resistant phenotypes in hybrid progenies is suggested.