TITLE:
Cryopreservation of Cat’s Claw (Uncaria tomentosa)
AUTHORS:
J. Perez, A. Guillen, K. Ramos, F. Engelmann, A. Abdelnour-Esquivel
KEYWORDS:
Uncaria tomentosa, Vitrification, Encapsulation-Dehydration, Conservation of Plant Genetic Resources, PVS2, Preculture, Regeneration Media
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.6 No.18,
November
26,
2015
ABSTRACT: Uncaria tomentosa presents tomentum that resembles cat’s claws, hence its common name, is a
plant that produces various secondary metabolites that are traditionally used in alternative medicine.
The natural distribution of this species has been affected by indiscriminate harvesting from its
habitat. In the present research, cryopreservation (liquid nitrogen, LN, -196°C) was evaluated as an
option for ex situ conservation of this species. The following techniques were evaluated: vitrification
and encapsulation-dehydration of apices, vitrification of cell suspensions, and seed desiccation
and vitrification. Preculture conditions and exposure times to LS and PVS2 were evaluated. Apex
survival was the highest (82%) with preculture in 0.25 M sucrose followed by incubation for 20
and 30 min in LS and PVS2, respectively, prior to cooling in LN. The encapsulation-dehydration
technique was evaluated by using sucrose preculture and different capsule moisture contents.
Survival of apices cooled in LN was not significantly different between treatments and varied from
31.8% to 52.9% for capsule moisture contents between 22.7% and 20.3%. For cell suspensions
precultured in 0.5 M sucrose, cell multiplication and formation of calli with very good appearance
were observed in 61.1% of the cultures following vitrification. For cryopreservation of seeds,
germination was 89.5% using the desiccation technique and 67.6% to78.1% using vitrification.