SummaryFor the induction and selection of double mutants with altered starch composition, a uniform (homohistont) amylose-free (amy') monoploid as basic plant is of vital importance. Therefore, new amf monoploids had to be developed via prickle pollination. And 26 monoploids were obtained which were screened in vitro for vigour, leaf size and for the percentage of monoploid cells. The number of monoploid cells was underestimated at about 28%. Seven vigorous monoploids were tested in vitro for tuberization capacity, which varied from 0 to 100%. After regeneration in vitro, 0 to 3.7 adventitious shoots per leaf explant were formed. The tuberization capacity of these shoots varied from 0 to 48. Two amfmonoploids were selected which were vigorous and tuberized well in vitro. They are the basis for the application of an in vitro mutation breeding protocol that should lead to the induction and selection of new starch mutants in potato.