title: Effects of some cryopreservation procedures on recalcitrant zygotic embryos of Ammocharis coranica.
abstract: BACKGROUND
  Cryopreservation, the most promising method for the long-term conservation of recalcitrant (desiccation-sensitive) seed germplasm, is often associated with high viability losses. Cryo-procedures involve a sequence of steps which must be optimised to reduce the impact of the stresses.
  
  
  OBJECTIVE
  This study reports on the effects of some of the steps of cryopreservation on the recalcitrant zygotic embryos of the amaryllid, Ammocharis coranica.
  
  
  METHODS
  Embryos were subjected to cryoprotection with glycerol and/or DMSO, rapid (flash) drying, and rapid (>100 degree C s(-1)) or slow (1 degree C s(-1)) cooling.
  
  
  RESULTS
  Rapid dehydration (from c. 2.7 to 0.9 g g(-1) over 60 min) and cooling had a detrimental effect on the viability of the embryos, which was exacerbated when these steps were applied sequentially. After cooling, seedling production (30%) was obtained only from embryos that had been cryoprotected with glycerol prior to drying and rapid cooling, while 30% of non-treated embryos and 70% of those that had undergone cathodic protection during flash drying produced callus.
  
  
  CONCLUSIONS
  Noting that no post-cryo survival of A. coranica embryos had previously been obtained, this study identified cryoprotection with glycerol and the incorporation of cathodic protection during flash drying as promising intervention points for future studies.
authors.affiliation: School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, South Africa.
authors.forename: Z
authors.initials: Z
authors.lastname: Nomali
authors.affiliation: School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, South Africa.
authors.lastname: Ngobese
authors.affiliation: School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, South Africa.
authors.lastname: Sershen
authors.affiliation: School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, South Africa. berjak@ukzn.ac.za.
authors.forename: P
authors.initials: P
authors.lastname: Berjak
authors.affiliation: School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, South Africa.
authors.forename: N W
authors.initials: NW
authors.lastname: Pammenter
mesh_terms: D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D003890:Desiccation; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D019668:Liliaceae / Q000187:drug effects* / Q000502:physiology; D036226:Seedlings / Q000502:physiology; D012639:Seeds / Q000187:drug effects* / Q000502:physiology
chemical_list: D003451:Cryoprotective Agents; D005990:Glycerol; D004121:Dimethyl Sulfoxide