A complete set of procedures comprising of the induction of haploid embryo development by pollination with irradiated pollen, embryo isolation and in vitro culture, haploid plant development, chromosome doubling by regeneration from leaf explants, acclimatization, self-pollination of DH plants and assessment of DH lines was performed in cucumber. Haploid and doubled haploid plants were obtained from all eight genotypes used in the study. The donor plant genotypes were evaluated by comparing the number of haploid embryos and DH plants obtained from each genotype. The influence of the donor plant genotype and its age on the regeneration and the yield of DH plants were evaluated. In order to optimize the method of chromosome doubling, the composition of medium was modified and the explants were divided into four groups with regard to the leaf sector used for regeneration. Acclimatization of DH plants to the greenhouse conditions was improved. Uniform, useful in breeding, DH lines were obtained.

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