In the scope of cabbage (Brassica oleracea var. capitata L.) breeding program the responsiveness of new donor genotypes to haploid embryogenesis was tested. Microspores were isolated from flower buds of donor plants, which were then cultivated on NLN medium, with and without the addition of 0. 02 % active charcoal. After 33 days, the embryos were counted. Charcoal had no statistically significant effect on embryo induction but embryos were more vigorous with higher germination efficiency. For three genotypes the embryo yield was higher than 50 embryos per petri dish, while the other five genotypes had lower number of embryos (11.4-39.0 per petri dish). The next step was either direct inoculation of embryos to the B5 regeneration medium or treatment of embryos with abscisic acid and desiccation before the inoculation to B5 medium. The percentage of regenerated embryos without ABA treatment was 23.8 – 46.0 %. The embryos with ABA treatment acheived higher germination percentage (37.0 % - 73.3 %) followed by normal plantlet development. From the total number of 671 regenerated plants analysed with flow cytometry, 275 plants (41 %) were dubled haploids. 98 % of dubled haploids were successfully acclimatized. In order to optimize the micropropagation and clone reproduction of already obtained lines from previous breeding experiments, nine inbred lines we inoculated to MS medium with different concentrations of hormones. The highest number of shoots were achieved on MS medium with 2 mg/l of IBA and 3 mg/l of BAP. The shoots were then transplanted to rooting medium. The percentage of rooting was between 50 % and 78 %. Rooting was induced on half-strength MS hormone free medium. The healthy and rooted regenerants were then planted in the green house, where the acclimatization rate was 97 %.
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