Cryopreservation of a threatened medicinal plant, Valeriana jatamansi Jones, using vitrification and assessment of biosynthetic stability of regenerants

Abstract

Background: Valeriana jatamansi Jones is a medicinal plant of the Himalayan region with high trade value. Since overexploitation of this wild species led it to be listed as threatened, a comprehensive conservation strategy is needed. Cryopreservation would be a useful complementary method to conventional conservation methods.

Objective: To develop a cryopreservation protocol for V. jatamansi with maintenance of biosynthetic stability of regenerants.

Materials and methods: In vitro shoot tips were cryopreserved using vitrification with either PVS2 or PVS3 and the efficacy of the two cryoprotectant mixtures compared. Regenerated plantlets were evaluated by HPLC analysis for contents of four valepotriates viz. valtrate, acevaltrate, didrovaltrate and IVHD valtrate.

Results: The highest shoot recovery (91.6%) after transfer to liquid nitrogen was obtained when shoot tips were treated with PVS2 at 0°C for 110 min, which was significantly higher than the highest recovery (73.3%) obtained using PVS3 for any duration tested. Evaluation of biosynthetic stability showed no variation in valepotriate contents between in vitro maintained and cryopreserved derived plantlets.

Conclusion: This protocol will be useful for the long-term conservation of this species as high frequency recovery and biosynthetic stability after cryopreservation were obtained.