title: Cold storage and cryopreservation of hops (Humulus l.) shoot cultures through application of standard protocols.
abstract: The USDA-ARS National Clonal Germplasm Repository (NCGR) stores the global diversity of Humulus for the US Plant Germplasm System as trellised plants in a field genebank. In vitro storage and cryopreservation are now considered excellent ways to provide medium and long-term storage for plant collections. Developing a new cryopreservation or cold storage protocol for every accession or genus of large multi-crop collections can be a very time consuming and long-term activity. We propose that standard cold storage and cryopreservation techniques used for other temperate crop genera would be successful for additional crops with few modifications. This study was initiated to determine if a large collection of hops germplasm could be successfully stored with techniques developed for unrelated genera. In this study we characterized the response of diverse Humulus genotypes to in vitro storage under low light at 4 degree C following techniques used for strawberry and mint plants, and cryopreservation in liquid nitrogen by slow cooling with a pear protocol. The average storage time without transfer for the 70 genotypes evaluated was 14 +/- 3.5 months with a range of 6 to 26 months. Mean recovery of cryopreserved shoot tips of accessions with 1-wk cold acclimation was 41 +/- 18 percent and increased to 54 +/- 13 percent with 2-wk cold acclimation. This demonstrates that application of a well-tested standard technique can provide a quick start for storing additional germplasm collections.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository, 33447 Peoria Road, Corvallis, OR 97333, USA. corbr@ars-grin.gov
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Reed
authors.forename: Nese
authors.initials: N
authors.lastname: Okut
authors.forename: Jeff
authors.initials: J
authors.lastname: D'Achino
authors.forename: Lee
authors.initials: L
authors.lastname: Narver
authors.forename: Jeanine
authors.initials: J
authors.lastname: DeNoma
mesh_terms: D000064:Acclimatization; D003080:Cold Temperature; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D006801:Humans; D027582:Humulus; D018520:Plant Shoots / Q000187:drug effects* / Q000254:growth & development
chemical_list: D003451:Cryoprotective Agents