Germplasm Conservation Techniques and Assessment of Physiological, Biochemical and Molecular Integrity of Indigenous, Endangered Dioscorea prazeri

Cryopreservation is a reliable and economical method for the long-term ex situ conservation of valuable genetic resources.The present study focuses on establishing novel regeneration strategies and on assessing various cryogenic methods using nodal explants/shoot apices and on developing in vitro technologies for germplasm conservation of Dioscorea prazeri.Pre-treatment, growth regulators, temperature conditions, treatment period for recovery and growth of explants were optimized and various germplasm conservation methods were conducted to attain the conservation and mass multiplication of the endangered therapeutic plant. The plants regenerated from vitrified tissues were evaluated for physiological stability through morphological characteristics, genetic stability using RAPD analysis and with key metabolites for biochemical characterization.An optimized vitrification method resulted in a regeneration level of 92 ± 2 %, whereas a method comprising encapsulation dehydration resulted in 75 ± 2 % regeneration. In contrast, only a 38 ± 2 % regeneration was achieved using an encapsulation vitrification method.Vitrification-based procedures significantly improve cryopreservation survival and can be successfully employed for the long-term conservation of Dioscorea species and, potentially, other medicinal plants.