In Vitro Conservation of Turbinicarpus (Cactaceae) Under Slow Growth Conditions

Absctract: The current work describes an in vitro conservation technique employing slow growth conditions in 16 threatened species and subspecies of the genus Turbinicarpus (Cactaceae), all native to the Chihuahuan Desert in Mexico. It was demonstrated that the addition of osmotic agents like mannitol (30 g L-1) and sorbitol (30 g L-1) to the culture medium, as well as low-temperature incubation (4 ± 0.5 °C), are able to reduce the in vitro growth rate without affecting the viability of shoots subjected to these treatments. The material that was kept under the aforementioned treatment conditions for 12 months was able to regenerate shoots through areole activation when transferred to media containing cytokinins. These shoots are able to root, and the generated plants can adapt and survive in soil, with similar efficiencies to those that were not subjected to slow-growth treatment. With this methodology it is possible to maintain a bank of viable tissues of these species in vitro, with minimal maintenance ...