Increase in thebaine content of Papaver bracteatum Lindl. after colchicine treatment of seeds. Annual fluctuations in thebaine level of individual plants.

From colchicine-treated seeds of Papaver bracteatum Lindl. some poppy plants were obtained that developed capsules richer in thebaine than the controls. The individual poppies were analyzed for capsule thebaine content annually for eight successive years, the results revealing significant year-to-year differences. One of the poppies, X7, (ca 5% thebaine) developed capsules consisting partly of polyploid tissue during the first and second year. This plant was propagated vegetatively to give a series (the X7 series) of new P. bracteatum plants. The capsule thebaine content of these individuals differed markedly the first two years, whereupon the alkaloid production decreased and appeared to level out and reach a value still clearly higher than the controls (mean values 2.3% and 1.3%, respectively). From seeds of four of the thebaine-rich poppies of the X7 series, four new series of P. bracteatum plants were obtained. The capsule thebaine level of these was significantly lower than that of the mother plants.