Twenty one diallel F1 dihaploid lines and their parental forms were tested in the field during 1992-1993 in order to evaluate their vitality compared to the parental forms, depending on their hybrid origin. F1 hybrids of diallel crossing between the varieties Plovdiv 7, Plovdiv 50, Kozarsko 541, Plovdiv 187 and the dihaploid lines 262, 123 and 550 (blue mould and TMV resistant) were dihaploidized by the method of induced androgenesis in vitro (Nitsch Y.P., Nitsch C., 1969). The sensitivity of the dihaploid lines - F1 hybrid combinations with lines 262, 123 and 550 was carried out by the method of mechanical inoculation (Noordam D., 1973) with serologically checked TMV isolates. The evaluation of the sensitivity of the regenerants obtained was based on symptoms manifested and extinction values of virus presence and accumulation (Edwards, Cooper, 1985). Data from the biometric measurements - plant height and leaf number - were processed by the methods of variational analysis and variance analysis. The analyses show that most of the F1 dihaploid lines are not of higher variability or with lower leaf number or plant height compared to their parental forms. Only a few of the F1 dihaploid lines were less vital by the characters analysed compared to both parents. These lines were hybrid combinations between two varieties as well as between a variety and a dihaploid line and/or between two dihaploid lines. Therefore, their reduced vitality can not be associated with the influence of a specific parent's genotype, but rather with the effect of the genotype of the hybrid combination in a homozygous state.