Phoma resistance in tomato seedlings.

Lobo, M., R. Navarro, B.N. Quintero and A.M. Jaramillo

Resistance to a new species of Phoma (Boerema, written communication) was tested by inoculating twice with a suspension of 1 x 10^6 spores by ml. of the fungus. Twenty four plants out of more than 4000 from 178 different genotypes were classified as immune (no disease symptoms). Those plants and the ones with the lowest intensity of disease were transplanted to a field in which the pathogen had been detected previously. All of the plants were eventually killed at the adult stage. In spite of the above, ti was observed that the advance of the disease was slower in such plants in comparison with susceptible plants (cv. Licato) included as controls. Data obtained with the most resistant materials are included in Table 1.

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                             Plants in each disease
                                   class (2)
Genotype          Source (1)   0  1   2   3   4   5
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L 1533           AVRDC        14  8   6   -   -   -
Tropic            UF           4  8   8   2   -  14
3668-2            UF           2  7   3   1   -   -
6058-FPBK         UF           1  -   1   -   -   -
6101-FPBK         UF           2  -   2   2   -   -
L 1519           AVRDC         1  -   1   1   6   -
L 1531           AVRDC         -  -  20   8   2  16
L 1150           AVRDC         -  1   4  16   7   6
Imp. Summertime   T.           -  1   3  13   7  16
Licato (control)  ICA          -  -   3  20  46  91
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(1) AVRDC: Asian Vegetable Research and Development Center
       UF: AREC Bradenton, Univ. of Florida
        T: Texas Agricultural Experiment Station
      ICA: Instituto Colombiano Agropecuario

(2)     0: Immune
        5: Dead