{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T22:35:56Z","timestamp":1787610956510,"version":"build-2736575974"},"reference-count":50,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2022,12,8]],"date-time":"2022-12-08T00:00:00Z","timestamp":1670457600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"ForestValue Research Program","award":["773324"],"award-info":[{"award-number":["773324"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Somatic embryogenesis (SE) is considered the most effective method for vegetative propagation of Norway spruce (Picea abies L. Karst). For mass propagation, a storage method that is able to handle large quantities of embryogenic tissues (ETs) reliably and at a low cost is required. The aim of the present study was to compare freezing at \u221280 \u00b0C in a freezer to cryopreservation using liquid nitrogen (LN) as a method for storing Norway spruce ETs. The possibility of simplifying both the pre-treatment and thawing processes in cryopreservation was also studied. The addition of abscisic acid (ABA) to the pre-treatment media and using polyethylene glycol PEG4000 instead of PEG6000 in a cryoprotectant solution were tested. Both the pre-and post-treatments on semi-solid media could be simplified by reducing the number of media, without any loss of genotype or embryo production capacity of ETs. On the contrary, the storage of ETs in a freezer at \u221280 \u00b0C instead of using LN was not possible, and the addition of ABA to the pre-treatment media did not provide benefits but increased costs. The lower regeneration rate after using PEG4000 instead of PEG6000 in a cryoprotectant solution in cryovials was unexpected and unwanted. The simplified pre-and post-treatment protocol will remarkably reduce the workload and costs in the mass-cryopreservation of future forest regeneration materials and in thawing the samples for mass propagations, respectively.<\/jats:p>","DOI":"10.3390\/ijms232415516","type":"journal-article","created":{"date-parts":[[2022,12,8]],"date-time":"2022-12-08T01:44:31Z","timestamp":1670463871000},"page":"15516","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Reducing Pre- and Post-Treatments in Cryopreservation Protocol and Testing Storage at \u221280 \u00b0C for Norway Spruce Embryogenic Cultures"],"prefix":"10.3390","volume":"23","author":[{"given":"Saila A.","family":"Varis","sequence":"first","affiliation":[{"name":"Natural Resources Institute Finland (Luke), Vipusenkuja 5, FI-57200 Savonlinna, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susanna","family":"Virta","sequence":"additional","affiliation":[{"name":"Natural Resources Institute Finland (Luke), Vipusenkuja 5, FI-57200 Savonlinna, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1868-5058","authenticated-orcid":false,"given":"Itziar A.","family":"Montalb\u00e1n","sequence":"additional","affiliation":[{"name":"Department of Forestry Science, NEIKER, 01080 Arkaute, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5442-5002","authenticated-orcid":false,"given":"Tuija","family":"Aronen","sequence":"additional","affiliation":[{"name":"Natural Resources Institute Finland (Luke), Vipusenkuja 5, FI-57200 Savonlinna, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,8]]},"reference":[{"key":"ref_1","unstructured":"FAO (2008). 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