Interspecific hybridization between L. peruvianum with L. esculentum has successfully been made at IVT, the Netherlands in 1980. Problems relating to this hybrid still exist especially in producing viable seeds that germinate in later generations. Backcrossing the F1 hybrid with L. esculentum produced seeds but did not produce seeds with L. peruvianum (Lindhout and Purimahua, 1988) while no or few seeds were produced after backcrossing F4 or F5 as a male to L. esculentum (Boukema and Den Nijs, 1984).
Backcrosses were made between F3 plants of this hybrid and a local L. esculentum variety (Intan). Use of the F3 as the staminate parent yielded fruits with undeveloped seeds but as a female no fruit was produced. Germination of this F3 seed was tested and only 35% germinated. Out of this, only two plants produced fruits and few plants had only flowers and no fruit. By treating pollen with IKI, a fertility test between F3 plants of non- fruitbearing and fruitbearing plants, with Intan as a control, was made. The fertility of both F3 plants was significantly lower than that of Intan (Table 1).
These results suggest the presence of both cross-(in the case of backcrossing) and self-incompatibilities, and are the reason that fruits with viable seeds were not produced even with assisted hand-pollination.
F4 seeds collected from F3 bearing-fruit plants had a higher percentage (almost 50%) of germination and its utilization is currently under study.
Table 1. Fertility percentage of F3 and Intan.
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Lines % Fertility of pollen
Range Mean
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F3 (unbearing-fruit) 6.0 - 14.4 11.3
F3 (bearing-fruit) 6.6 - 22.6 15.9
Intan 72.6 - 89.3 78.8
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Literature cited:Boukema and Den Nijs (1984). Synopsis Eucarpia tomato working group, Wageningen, 107-112.
Lindhout and Purimahua (1988). TGC report 38, 29.