Selection for high thebaine/low morphine content in Papaver somniferum L.

Abstract

High contents of thebaine in the ripe capsules were observed in the L4 and I5 generations from a spontaneous mutant, similar to the observations in earlier generations. Outcrossings of plants with normal morphine contents still take place. Some correlation was found for ‘high thebaine content in mother capsule/high frequency of plants with thebaine as major alkaloid in progeny’ but no correlation was obtained for thebaine content and capsule size. Thebaine in these plants accumulates in a way similar to that of morphine in normal plants. Varying light intensities had no influence on the the-baine/morphine relationship in the plant. A retarded development in the pre-flowering period was observed in breeding lines with high frequencies of thebaine plants.