Nuclear DNA content in 84 Hosta cultivars was measured by flow cytometry. A
s an internal standard we used the closely related Agave americana, the lat
ter was calibrated against other reference species. Propidium iodide values
were 20% higher than DAPI values, indicating a lower AT/GC ratio for Hosta
. Ten new tetraploid plants were found in addition to the only tetraploid k
nown so far; H. ventricosa. Small forms of the tetraploid H. ventricosa tur
ned out to be triploid hybrids. Three other triploids were discovered. Thre
e supposed tetraploids turned out to be diploid. In five plants the ploidy
levels of the germ layers L1 and L3 appeared to be different. In these case
s thick leaves coincides with a tetraploid DNA content. The DNA contents as
measured in these ploidy chimeras coincide with differences in leaf colour
, thus giving an opportunity to analyze the build-up of Hosta plants. In ge
neral, analysis of the nuclear DNA content can be used as a simple means to
increase the possibilities for creating new cultivars in this economically
important perennial.