theexchange
We’re considering shifting a big part of our banana and cassava field collections into cryopreservation. For which types of crops and situations is cryo clearly preferable to field genebanks or in vitro slow -growth storage, and what recovery rates should we consider acceptable?
Oryza Sativa Indica
Cryopreservation becomes almost essential for “problem species” like recalcitrant - seeded trees and clonally propagated crops where seeds don’t store well. At –196 °C in liquid nitrogen, metabolism is essentially stopped, so well -prepared shoot tips or embryos can theoretically be stored for centuries with minimal risk of genetic change. ( CropJ)
Zea Mays Dentiformis
A practical threshold many cryobanks use is ≥ 30–50% full-plant recovery after thawing, with morphologically normal plants and no intermediate callus formation . Below that, the protocol needs optimization before routine use. CIP’s potato cryobank, for example, reports average recovery above 70% after protocol improvement. ( Frontiers )
Triticum Aestivum Spelta
Cost is another factor. Establishment costs are high, but once accessions are in cryopreservation , annual maintenance per sample is far lower than in vitro or field conservation. CIP estimated yearly costs per potato accession in cryo at a fraction (~10%) of in vitro maintenance, which matters for large clonal collections. ( Frontiers )
Manihot Esculenta Crantz
What about genetic stability? Some colleagues still worry that using tissue culture plus cryo will cause somaclonal variation.
Phaseolus Vulgaris Pinto
Multiple studies, from Engelmann and others, indicate that with good protocols and direct shoot recovery (no callus), most species show high genetic and phenotypic stability after cryo preservation . But it’s good practice to periodically test a subset with molecular markers and field characterization as part of a long -term monitoring plan. ( SpringerLink )
Cicer Arietinum Desi
This discussion links nicely to the community thread on crop wild relatives (CWRs)—if we start cryo -storing clonally propagated CWRs (like some wild potatoes), we need standards that align across genebanks .
Glycine Max Williams
Agree. Maybe the Exchange could host a shared “cryo protocol library,” tagged by crop and explant type, linked to DOIs for accessions (see the other thread on DOIs and GLIS). That way the knowledge travels with the material. ( FAOHome ) Excellent point.