Field experiment was conducted to study the diversity in growth parameters
and alkaloid production between diploidy and tetra ploidy levels of Datura stramonium
and Datura innoxia plants. Increases in plant height. number of branches and fresh
weight of different plant organs were observed at all growth stages. for tetraploid of
both Datura sPP. as compared with those of diploidy plants. Moreover. chromosome
doubling led to increase fruit yield by 12% for D. stramonium and by 82% for D.
innoxia. HPLC-analysis revealed that all plant organs of two Datura spp had relatively
high concentrations of hyoscine and hyoscyamine. Hyoscine remained the principal
alkaloid in roots. stem and leaves of diploidy and tetraploidy D. stramonium and D.
innoxie, throughout the growing season. Fruits and leaves of both ploidy levels of two
Datura spp were generally considered to be the organs with the higher amounts of
alkaloids. Hyoscyamine was the main alkaloid in the fruits of diploidy and tetraploidy
D. stramonium. whereas hyoscine was the main alkaloid in D. innoxia fruit. A great
enhancement effect of chromosome doubling on concentration and amount of
hyoscine and hyoscyamine in different plant parts was obtained by D. innoxia. Amount
of alkaloids in tetraploid D. innoxia plant ranged between 177% and 406% relative to
those occurred in diploid plant. at all growing stages. As for D. stramonium the
consistent increase in hyoscine and hyoscyamine concentrations due to chromosome
doubling was occurred only by roots. At harvest. tetraploidy D. stramonium plant had
more alkaloids than those produced by diploid one. Positive correlations were
observed between alkaloid formation in roots and stem of both ploidy levels of two
Datura spp and its total N and soluble N contents.