Transformation to auxin-autotrophy and its reversibility in a mutant line of Crepis capillaris callus culture

Summary From a callus culture which was started from explants of a single plant of Crepis capillaris, a line was isolated which could grow on auxin- and kinetin-free medium (in contrast to the other lines of the culture). The calluses of this habituated line grew on hormone-free medium as teratomas. Regenerated plants were obtained from the habituated line and from other lines of the culture as control. In the secondary callus cultures which originated from these plants, the subcultures belonging to the initially transformed line no longer had the ability to grow on hormone-free medium. Since this line was also a chromosome mutant and the same mutation was present in its regenerated plants and in the secondary culture line of them, the loss of the auxin-autotrophy cannot be explained in this case on the basis of a selection of cells with karyotypes different from those of the primary culture.