Indian Institute of Vegetable Research, Varanasi, India.
A total of 550 lines of tomato were tested for resistance to ToLCV using both natural infestation and rigorous single plant whitefly inoculation technique at Indian Institute of Vegetable Research, Varanasi. Initially all the lines were screened in the natural conditions to cut down the population size for artificial screening. Many of the chilense-derived and hirsutum-derived lines exhibited high field resistance to ToLCV in the three consecutive experiments conducted from 2004 to 2006. These lines were further screened using single plant whitefly inoculation technique in the glasshouse. Chilense derived Fla-478 and hirsutum-derived H-88-78-1 lines showed high resistance in artificial conditions as well.
These two lines were crossed with highly susceptible Punjab chhuhara to develop F2, B1 and B2 populations to study the inheritance of resistance. All the generations were screened artificially. The F1 between the resistant lines and susceptible cultivar Punjab chhuhara were susceptible. Segregation pattern of the resistance and susceptibility indicated to complementary gene action with 9:7 ratio of susceptible and resistance individuals. Confirmation of the complementary gene action in F3 families of these lines is underway. Towards making use of these lines in resistance breeding program and integration of marker assisted selection, set of F2 population was advanced to F3 generation to develop recombinant inbred lines. Currently F3 individuals are being advanced F4 using single seed descent method.
