CALLUS INDUCTION AND MORPHOGENESIS IN DIOSCOREA DUMETORUM FOR STEROID PRODUCTION

Diosgenin is characteristic of the genus Dioscorea (Dioscoreaceae), which is used in partial synthesis of steroid drugs. It was not detected in the crude sapogenin extract of Dioscorea dumetorum and in the calluses. Callus was induced from the meristem of the two genotypes and maintained successfully on Murashige and Skoog's medium (MS) supplemented with 0.1mg/l of 2, 4-dichlorophenoxyacetic acid (2,4-D). Shoots induced from nodal cuttings of the white and yellow genotypes regenerated plantlets, which were subsequently maintained on MS medium, and Linsmaier and Skoog's medium (LS) supplemented with 0.5mg/l kinetin. Control of microbial contamination was achieved with tetracycline. Microtubers were also obtained from the yellow genotype plantlet growing on the MS medium. Steroids, especially the Δ 5 , 3-hydroxy steroids were detected only in the yellow genotype callus. Keywords : Dioscorea dumetorum; diosgenin; 3-hydroxy steroids; callus; shoot culture; meristem culture; yellow genotype Nigerian Journal of Natural Products and Medicine Vol.7 2003: 5-8