VIEW ARTICLE

Characterization of a Factor of Resistance in Curly Top Virus-Resistant Tomatoes. Peter E. Thomas, Plant Pathologist, Plant Science Research Division, ARS, USDA, Irrigated Agriculture Research and Extension Center, Prosser, Washington 99350; Mark W. Martin, Geneticist, Plant Science Research Division, ARS, USDA, Irrigated Agriculture Research and Extension Center, Prosser, Washington 99350. Phytopathology 62:954-958. Accepted for publication 28 February 1972. DOI: 10.1094/Phyto-62-954.

Studies on that portion of the resistance to curly top virus in certain tomato cultivars operative after inoculation suggest that resistance is not the result of: (i) selective immunities to specific virus strains; (ii) tolerance or masking of symptoms; (iii) recovery from symptoms; (iv) restriction of virus to the roots; (v) resistance to systemic translocation of virus; (vi) localization of virus at sites of insect inoculation; or (vii) slow movement of virus from sites of inoculation to sites of infection. The resistance apparently results because virus delivered by the vector fails to establish infection as often in resistant as in susceptible plants.