Genotypes and alkaloid contents of Datura metel varieties

Datura metel L. var. muricata (BERNH.) DANERT was found to be double recessive with respect to the genes concerning the color and form of the corolla by breeding experiments involving four varieties, i.e. var. metel (white, simple corolla), var. rubra (purple, simple), var. fastuosa (purple, double or triple) and var. muricata (white, purple). The results support the proposal by Danert and others that these variants should be considered as varieties or forms of a single species, Datura metel. The analysis of tropane alkaloids in the seeds, flowers, and leaves of these four varieties showed that scopolamine was always dominant over hyoscyamine. The range of the scopolamine content (% of dry weight) of seeds, flowers, and leaves was 0.294 (var. rubra)-0.631 (var. fastuosa), 0.190 (var. metel)-0.698 (var. rubra), and 0.042 (var. rubra)-0.255 (var.metel), respectively. These findings proved that all the varieties, including var. muricata, which exhibited medium scopolamine content among the varieties, can be utilized as sources of scopolamine.