STUDIES ON IN VITRO PROPAGATION METHODS IN CACTUS SPECIES OF THE GENERA MELOCACTUS, CEREUS AND LOBIVIA
In vitro propagation methods are frequently used for the conservation of rare cacti and also for the production of plants for commercial purposes. Here we report on the micropropagation by axillary shoot proliferation at the cactus species Melocactus salvadorensis, Lobivia tegeleriana and Cereus jamacaru being important as ornamentals and also as a forage and fruit crop in the case of the latter one. Depending on species, explants were derived from surface-sterilized shoots or seedlings germinated in vitro. Transverse or longitudinal slices of donor shoots were incubated on MS media supplemented with 1, 2 or 4 mg L-1 BAP. Addition of NAA (0.1 mg L-1) had positive effect on shoot induction. A 50% reduction of basal salt, vitamin and sugar concentration of hormone-free MS medium helped vitrified or abnormal shoots of C. jamacaru to recover and significantly improved rooting rate. Hyperhydricity was frequently observed among adventitious shoots induced on secondary explants of L. tegeleriana, while it did not occur in M. salvadorensis. Besides micropropagation, somatic callus cultures of L. tegeleriana have also been generated to develop a plant cell plant system. Somatic cell cultures make possible manipulations at the cellular level and production of somaclonal variants of interest to cactus enthusiasts. Using MS-based induction media supplemented with 2,4-D (2 or 4 mg L-1) calli of granular structure were produced after the passage on MS medium containing 1-1 mg L-1 2,4-D and kinetin, respectively. Vigorously growing plantlets of normal morphology have been regenerated on this medium, while plantlets regenerated from calli transferred to hormone-free MS medium grew slower and exhibited abnormal characteristics.
Monostori, T., Tanács , L. and Mile, L. (2012). STUDIES ON IN VITRO PROPAGATION METHODS IN CACTUS SPECIES OF THE GENERA MELOCACTUS, CEREUS AND LOBIVIA. Acta Hortic. 937, 255-261
micropropagation, axillary shoot proliferation, callus culture, somatic embryos, vitrification