Lawton and Mac Neil (1986) reported the existence of race 1 of Pseudomonas syringae pv. tomato in Canada. The latter was detected also in Bulgaria (Bogatsevska et al., 1989). There are no reports till now about cultivated tomato lines resistant to P. syringae race 1.
After artificial inoculation of 300 tomato lines from "Maritza" Veg. Crops Res. Institute-Plovdiv, we found resistance in 13 lines as it is shown in Table 1. The evaluation was made after Chambers and Merriman (1975). Three lines - 4069/88, 3722/88 and 1109/88 showed homozigous resistance. To our information they are the first reported cultivated lines resistant to race 1 of P. syringae They have different wild species in their pedigree. The other lines under study segregated for resistance. It is worth noting that susceptible plants had only a few spots on the leaves. We are on the way of distinguishing stable resistant lines because of their good economical properties and resistance to other diseases. The genetics of the factors controlling resistance to race 1 of P. syringae is under investigation.
Table 1. Reaction of some breeding lines to race 1 of P. syringae
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Lines Number of plants with rating
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No/1988 0 1 2 3 4
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4069 50 - - - -
3722 50 - - - -
1109 50 - - - -
2839* 36 14 - - -
3301* 50 20 - - -
3308* 38 12 - - -
3323* 38 12 - - -
3259* 48 12 - - -
2928* 38 12 - - -
2574* 44 16 - - -
3306 20 30 - - -
2917** 28 12 - 4 16
3294* 34 26 - - -
ONT 7710 - 18 12 15 5
Ottawa 78 - - - - 50
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* Only one spot on S-plant.** One to four spots on S-plants.
Literature cited:
Bogatsevska, N., V. Sotirova and L. Stamova 1989 Tomato Genetics Cooperative Report 39: 7.
Chambers, S. and R. Merriman 1975 Austr. J. Agric. Res. 26:657-663
Lawton, M. and M. MacNeil 1986 Can. J. of Plant Pathology. 8:85-87.