Shoot Tip Cryopreservation as a Conservation Tool for Species of Quercus: Effects of Species and Environment on Recovery

Cryo Letters. 2021 May-Jun;42(3):159-167.

Abstract

Background: The seeds of oak (Quercus) species cannot be conserved in conventional seed banks and require cryobiotechnologies for long-term, ex situ conservation.

Objective: To evaluate shoot tip cryopreservation as a method for conserving oaks ex situ.

Materials and methods: Droplet vitrification was tested on tips from shoot cultures of four oak species; the effects of three preculture and recovery growth conditions on survival and growth were tested with Q. virginiana.

Results: Shoot tips of Q. virginiana gave the best survival through liquid nitrogen exposure (56%), compared with Q. hinckleyi (20%), Q. suber (12%), and Q. gambelii (0%). In further tests with Q. virginiana, recovery in the alternating temperature regime (27 C / 151C, 16 h / 8 h) gave significantly better survival than at constant 21sC and significantly better growth than constant 26CC.

Conclusion: While there are species differences in the response to droplet vitrification, these results indicate that shoot tip cryopreservation should be explored further as a conservation tool for oaks.

MeSH terms

  • Conservation of Natural Resources / methods*
  • Cryopreservation*
  • Cryoprotective Agents / pharmacology
  • Plant Shoots*
  • Quercus*
  • Vitrification

Substances

  • Cryoprotective Agents