Three pairs each of Atom and Ontario 7710, Plodiv 2305 and Ontario 7710, and Plovdiv 2722 and Ontario 7710 plants were used for the test which can thus be considered as covering three repetitions. The results obtained for all three repetitions are shown in Table 1. With the bacterial test, classification of the plants was simple. The susceptible control plants developed numerous spots whereas the resistant control plants either developed no symptoms or a very small number of necrotic spots. In the case of Fenthion test, discrimination between plants was even simpler. We observed either a total absence of necrosis on plants susceptible to P. tomato or very extensive leaf necrosis on plants resistant tot he bacteria. Notwithstanding, one difference is to be noted: the Plovdiv 2722 line revealed less intense necrosis than Ontario 7710 and the two other resistant lines. This had also been noted with the F1 Monallbo x Plovdiv 2722 hybrid. We had already observed this lesser sensibility to Fenthion in Lycopersicon peruvianum, a species which belongs to the same subgeneric complex as L. chilense from which Plovdiv 2722 obtains its resistance.
The findings reported in table 1 show no segregation in the F2 populations and none in the plant populations obtained from crossing F1 plants with the Atom, Plovdiv 2305 and Plovdiv 2722 lines carry the same Pto gene as the Ontario 7710 line.
Table 1. Response (number of plants) of lines and populations after inoculation with Pseudomonas tomato and after spraying with Fenthion insecticide
Laterrot H. and Philouze J., 1986, TGC Report 36:23.Bogatsevska, N., Stamova, L. and Yarda M., 1990. TGC Report 40:6.
Stamova L., Bogatsevska N. and Yardanov M., 1990. Proc. XIth Eucarpia Tomato Meeting, Torremolinos, Spain, March 6-8, 1990, 25-29.