title: POST-HARVEST EMBRYO DEVELOPMENT IN GINSENG SEEDS INCREASES DESICCATION SENSITIVITY AND NARROWS THE HYDRATION WINDOW FOR CRYOPRESERVATION.
abstract: Despite its self-pollinating characteristics, Korean ginseng germplasm is mainly maintained in clonal gene banks as there is no defined approach to the long-term conservation of its seed, including the most appropriate stage of embryo development for storage.
  
  
  
  The aim of this study was to reveal the effect of embryo development on desiccation tolerance and cryopreservation success in ginseng seeds.
  
  
  
  Seeds of Korean ginseng (Panax ginseng C.A. Meyer) at three post-harvest stages (immediately after harvesting and following treatments to enable internal growth of the embryo) were desiccated and cryopreserved.
  
  
  
  The hydration window for the >80% dehiscence and germination of cryopreserved ginseng seeds varied with embryo developmental stage: 3-9% moisture content (MC) for both unpulped and undehisced seeds when the embryo was 0.1 the length of the endosperm, 7-10% MC for dehisced seeds (0.5 embryo:endosperm) and 9-11% MC for seeds with fully developed embryos (0.9 embryo:endosperm). Whilst dried (4-8% moisture content) and undehisced seeds within fruits (unpulped seeds) lost more than half their viability during 1 year's storage at room temperature, cryopreservation enabled germination levels of c. 90%. Overall, 432 accessions of Korean ginseng landraces have been cryopreserved using undehisced seeds with or without fruits.
  
  
  
  Post-harvest treatment of Korean ginseng seeds to enable embryo development decreases tolerance of very low MCs, and thus narrows the hydration window for cryopreservation. Fresh-harvested and unpulped seeds that have been dried to c. 5% MC are recommended for long-term cryogenic storage.
authors.affiliation: National Agrobiodiversity Center, RDA-NAAS, Suwon, Korea.
authors.forename: E
authors.initials: E
authors.lastname: Han
authors.affiliation: Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, Univ. Guelph, Ontario N1G 2W1, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Popova
authors.affiliation: National Agrobiodiversity Center, RDA-NAAS, Suwon, Korea.
authors.forename: G
authors.initials: G
authors.lastname: Cho
authors.affiliation: Division of Plant Science and Resources, Chungnam National University, Daejeon, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Park
authors.affiliation: Dept. of Well-being Resources, Sunchon National University, Suncheon, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.affiliation: Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK.
authors.forename: H W
authors.initials: HW
authors.lastname: Pritchard
authors.affiliation: Dept. of Well-being Resources, Sunchon National University, Suncheon, Korea. cryohkim@sunchon.ac.kr.
authors.forename: H H
authors.initials: HH
authors.lastname: Kim
mesh_terms: D015925:Cryopreservation; D003890:Desiccation; D018525:Germination; D005894:Panax / Q000502:physiology*; D012639:Seeds / Q000254:growth & development*