Variation of Alkaloid Production in Nicotiana rustica Callus Cultures

Abstract

Callus cultures have been established from the seed, root and leaf of Nicotiana rustica L. var. brasilia in a synthetic medium containing 1 μM 2,4‐D and μM kinetin. These callus tissues behaved similarly not only in growth and organogenesis but also in nicotine production. The nicotine contents of callus cultures, which were in the order of 0.25–0.58% of dry weight during a few passages subsequent to callus induction, rapidly decreased to trace amounts in succeeding subcultures in association with the decline of the root‐regenerating activity. On the other hand, free cells prepared from a callus tissue in the third passage developed into individual clones showing wide differences in growth and nicotine production. One of these clones gave rise to a relatively stable strain which is capable of producing nicotine at a high rate (0.29% of dry weight) in the absence of organization. The significance of these findings is discussed in connection with some results which have been reported for other callus cultures of Nicotiana species.