Samenvatting

There are two aims of this thesis; one is selecting 2n pollen producers from F1 hybrids of T. gesneriana x T. fosteriana tulip hybrids crossing experiment. Furthermore, to test one year old tulip seedlings for ploidy levels of the F1 progenies in order to determine the result of the function of the 2n pollen for which the genotypes were previously selected. In this thesis report, two activities have been attempted to achieve Polyploidization in tulip and lily by two different approaches. The second objective was to investigate the efficiency of in vitro chromosome doubling by using different concentrations of oryzalin in lily .